Heat engine

Abstract

A rotary heat engine (100) comprising a rotor (200) centred on, and rotatable about, a rotational axis (202) and a stator (300) which bounds the rotor (200). The stator (300) defines a radially inner surface (304) which faces a radially outer surface (204) defined by the rotor (200). The rotor radially outer surface (204) defines a plurality of rotor combustion chambers (210). The stator radially inner surface (304) defines a plurality of stator combustion chambers (310). As the rotor (200) rotates relative to the stator (300), rotor-stator combustor volumes are formed each time one each of the stator combustion chambers (310) and rotor combustion chambers (210) overlap such they are in fluid communication. The rotary heat engine (100) is configured to perform thermodynamic cycles as the rotor (200) rotates relative to the stator (300), at least part of each thermodynamic cycle occurring within each rotor-stator combustor volume formed. Each thermodynamic cycle comprises a combustion stage in which a combustion event results in a first pressure condition (P1) and an exhaust stage at a second pressure condition (P2). The rotary heat engine (100) being configured such that the exhaust stage of the first rotor-stator combustor volume starts after the ignition of a combustion event in the second rotor-stator combustor volume.

Description

[0001] HEAT ENGINE

[0002] The present disclosure relates to a heat engine.

[0003] Background

[0004] As is well understood in the art, a heat engine is a system that converts heat to usable energy, particularly mechanical energy, which can then be used to do mechanical work. Heat engines provided as internal combustion engines are well known and have been developed for many years to improve their efficiency for a given power output. However, there is a pressing environmental need for further improvements in internal combustion engine design in order to reduce greenhouse gas emissions.

[0005] Hence a heat engine which is highly efficient and / or is configurable for use with environmentally friendly fuels, and yet has a comparable or greater power output than examples of the related art, is highly desirable.

[0006] Summary

[0007] According to the present disclosure there is provided an apparatus, system and method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows.

[0008] Accordingly, there may be provided a rotary heat engine (100). The rotary heat engine may comprise a rotor (200) centred on, and rotatable about, a rotational axis (202), and a stator (300) which bounds the rotor (200). The rotor (200) may be rotatable relative to the stator (300). The stator (300) may define a radially inner surface (304) which faces a radially outer surface (204) defined by the rotor (200). The rotor radially outer surface (204) may define a plurality of rotor combustion chambers (210). The stator radially inner surface (304) may define a plurality of stator combustion chambers (310).

[0009] The rotary heat engine (100 may be configured such that as the rotor (200) rotates relative to the stator (300), rotor-stator combustor volumes are formed each time one each of the stator combustion chambers (310) and rotor combustion chambers (210) overlap such they are in fluid communication.

[0010] The rotary heat engine (100) may be configured to perform thermodynamic cycles as the rotor (200) rotates relative to the stator (300), at least part of each thermodynamic cycle occurring within each rotor-stator combustor volume formed. Each thermodynamic cycle may comprise a combustion stage in which a combustion event results in a first pressure condition (P1); and an exhaust stage at a second pressure condition (P2). The rotary heat engine (100) may be configured such that the exhauststage of the first rotor-stator combustor volume starts after the ignition of a combustion event in the second rotor-stator combustor volume.

[0011] The rotary heat engine (100) may be configured such that the first pressure condition (P1) is controlled to occur in each rotor-stator combustor volume formed and in one rotor-stator combustor volume at a time.

[0012] Each rotor combustion chamber (210) and stator combustion chamber (310) may be configured such that as the rotor (200) rotates relative to the stator (300) the second rotor-stator combustor volume is formed after the first rotor-stator combustor volume is formed.

[0013] The rotor combustion chamber (210) and stator combustion chamber (310) may be configured such that as the rotor (200) rotates relative to the stator (300), the second rotor-stator combustor volume is formed before the first rotor combustion chamber and first stator combustion chamber forming the first rotor-stator combustor volume become fluidly isolated from one another.

[0014] The rotor combustion chamber (210) and stator combustion chamber (310) may be configured such that the first rotor-stator combustor volume and second rotorstator combustor volume are formed in series, and the second rotor-stator combustor volume is formed next in the series after the formation of the first rotorstator combustor volume.

[0015] Each thermodynamic cycle may comprise an inlet stage at a third pressure condition (P3) which starts prior to formation of each rotor-stator combustor volume.

[0016] The first pressure condition (P1) may have a higher value than the second pressure condition (P2) and the third pressure condition (P3). The third pressure condition (P3) may have a higher value than the second pressure condition (P2).

[0017] The first pressure condition (P1) may be at least 5 times, but no more than 300 times, greater than the second pressure condition (P2). The first pressure condition (P1) may be at least 5 times, but no more than 50 times, greater than the third pressure condition (P3).

[0018] Each rotor combustion chamber (210) and each stator combustion chamber (310) may have a fixed volume.

[0019] The number of rotor combustion chambers (210) may not be equal to the number of stator combustion chambers (310).

[0020] The rotary heat engine (100) may comprise three rotor combustion chambers (210) and two stator combustion chambers (310).The rotary heat engine (100) may comprise four rotor combustion chambers (210) and three stator combustion chambers (310);

[0021] The rotary heat engine (100) may comprise five rotor combustion chambers (210) and four stator combustion chambers (310); or

[0022] The rotary heat engine (100) may comprise six rotor combustion chambers (210) and five stator combustion chambers (310).

[0023] Each rotor combustion chamber (210) may have a leading edge (212) and a trailing edge (214). Each stator combustion chamber (310) may have a leading edge (312) and a trailing edge (314). Each rotor combustion chamber (210) may be defined by a rotor surface base wall (218) which faces the stator (300) and extends from the leading edge (212) to the trailing edge (214) of the rotor combustion chamber (210) to define a rotor combustion chamber surface (220) extending at least part of the way from the leading edge (212) to the trailing edge (214) of the rotor combustion chamber (210).

[0024] The rotor (200) may comprise a firstair inlet port (230). The first air inlet port (230) may be is configured for communication with a source of air (600). The first air inlet port (230) may be provided proximate to, but circumferentially spaced apart from, each rotor combustion chamber trailing edge (214). The first air inlet port (230) may open on the rotor radially outer surface (204).

[0025] The rotary heat engine (100) may comprise a leakage flow mitigation feature (240) wherein the leakage flow mitigation feature (240) comprises: a leakage recess (242) which opens at an opening (244) onto the rotor radially outer surface (204) and extends part of the way across the rotor radially outer surface (204) between each rotor combustion chamber trailing edge (214) and the first air inlet port (230) on the rotor radially outer surface (204); and a first circumferential recess (250) which extends along the rotor radially outer surface (204) from the leakage recess (242) towards and past the respective rotor combustion chamber (210), terminating at a first lead region (252) circumferentially spaced apart from the respective rotor combustion chamber leading edge (212); the first circumferential recess (250) configured such that, as the rotor (200) rotates relative to the stator (300), the first circumferential recess (250) is in flow communication with the exhaust port (320) before the respective rotor combustion chamber (210).

[0026] The leakage flow mitigation feature (240) may comprise: a second circumferential recess (260) which extends along the rotor radially outer surface (204) from the leakage recess (242) towards and past the respective rotor combustion chamber (210), terminating at a second lead region (262) circumferentially spaced apart from therespective rotor combustion chamber leading edge (212); the second circumferential recess (260) configured such that, as the rotor (200) rotates relative to the stator (300), the second circumferential recess (260) is in flow communication with the exhaust port (320) before the respective rotor combustion chamber (210); and the second circumferential recess (260) is spaced apart from the first circumferential recess (250) by the respective rotor combustion chamber (210).

[0027] The rotary heat engine (100) may comprise a leakage flow mitigation feature (240). The leakage flow mitigation feature (240) may comprise a leakage recess (242) which opens at an opening (244) onto the rotor radially outer surface (204) and extends part of the way across the rotor radially outer surface (204) between each rotor combustion chamber trailing edge (214) and the first air inlet port (230) on the rotor radially outer surface (204). The leakage flow mitigation feature (240) may comprise a first leakage passage (1250) which extends from the leakage recess (242) towards and past the respective rotor combustion chamber (210), terminating at a first leakage aperture (1252) circumferentially spaced apart from the respective rotor combustion chamber leading edge (212). The first leakage passage (1250) may be configured such that, as the rotor (200) rotates relative to the stator (300), the first leakage aperture (1252) is in flow communication with the exhaust port (320) before the respective rotor combustion chamber (210).

[0028] The leakage flow mitigation feature (240) may comprise a second leakage passage (1260) which extends from the leakage recess (242) towards and past the respective rotor combustion chamber (210), terminating at a second leakage aperture (1262) circumferentially spaced apart from the respective rotor combustion chamber leading edge (212). The second leakage passage (1260) configured such that, as the rotor (200) rotates relative to the stator (300), the second leakage aperture (1262) is in flow communication with the exhaust port (320) before the respective rotor combustion chamber (210). The second leakage passage (1260) may be spaced apart from the first leakage passage (1250) by the respective rotor combustion chamber (210).

[0029] The leakage recess (242) extends from its opening (244) to a radially inner base (270), and reduces in width between the opening (270) and the inner base (270).

[0030] The rotor surface base wall (218) may defines a step feature (280) which extends transversely across the rotor combustion chamber (210), the step feature (280) being provided at least 50% but not more than 99% of the distance between the rotor combustion chamber leading edge (212) and the rotor combustion chamber trailing edge (214); the distance of the rotor surface base wall (218) from the rotor radially outersurface (204) decreasing between the step feature (280) and the rotor combustion chamber trailing edge (214), and defining a surface (224) therebetween.

[0031] The rotary heat engine (100) may be provided with a corresponding exhaust port (320) which opens onto the stator radially inner surface (304), and is spaced apart from each stator combustion chamber (310) around the circumference of the stator radially inner surface (304); and each rotor combustion chamber (210) extends around the circumference of the rotor radially outer surface (204) such that they span the distance between the corresponding stator combustion chamber (310) and exhaust port (320) such that a first part of the exhaust stage is defined by: a part of a period of a revolution of the rotor (200) about the rotational axis (202) when the rotor combustion chamber (210) is in fluid communication with the corresponding exhaust port (320) and the corresponding stator combustion chamber (310).

[0032] Each first air inlet port (230) may be located such that a second part of the exhaust stage is defined by: a part of a period of a revolution of the rotor (200) about the rotational axis (202), when the rotor combustion chamber (210) overlaps the corresponding stator combustion chamber (310) and the exhaust port (320), such that the first air inlet port (230) is in flow communication with the exhaust port (320) via the respective stator combustion chamber (310) and rotor combustion chamber (210).

[0033] A third part of the exhaust stage may be defined by a part of a period of a revolution of the rotor (200) about the rotational axis (202) when each rotor combustion chamber (210) is in fluid communication with the corresponding exhaust port (320) and fluidly isolated from the corresponding stator combustion chamber (310).

[0034] The rotor (200) may comprise a second air inlet port (232) for communication with the source of air (600), the second air inlet port (232) being provided proximate to, but circumferentially spaced apart from, the first air inlet port (230), such that the second air inlet port (232) is circumferentially spaced apart from the respective rotor combustion chamber trailing edge (214) by the respective first air inlet port (230).

[0035] The second air inlet port (232) may be located such that during a revolution of the rotor (200) about the rotational axis (202), the second air inlet port (232) is in flow communication with each stator combustion chamber (310) for a part of a period when the proximate rotor combustion chamber (210) is fluidly isolated from the respective stator combustion chamber (310).

[0036] The first air inlet port (230) and the second air inlet port (232) may be located such that during a revolution of the rotor (200) about the rotational axis (202): in a first sub-period of the period when the rotor combustion chamber (210) is fluidly isolated fromthe stator combustion chamber (310), the first air inlet port (230) and the second air inlet port (232) are in flow communication with the respective stator combustion chamber (310); and in a second sub-period of the period when the rotor combustion chamber (210) is fluidly isolated from the stator combustion chamber (310), the first air inlet port (230) is fluidly isolated from the respective stator combustion chamber (310) and the second air inlet port (232) is in flow communication with the respective stator combustion chamber (310).

[0037] The rotor combustion chambers (210) may be equally spaced around the rotor (200) and each extend at least 25 deg, but no more than 70 deg, around the outer circumference of the rotor (200). The stator combustion chambers (310) may be equally spaced around the stator (300) and each stator combustion chamber (310) extends at least 15 deg, but no more than 35 deg, around the inner circumference of the stator (300). The stator combustion chamber trailing edge (314) may be at least 15 deg but no more than 60 deg around the inner circumference of the stator (300) from the exhaust port (320).

[0038] The stator (300) may comprise a third air inlet port (330) for communication with the source of air (600), the third air inlet port (330) being provided circumferentially spaced apart from the corresponding exhaust port (320).

[0039] The stator combustion chamber leading edge (312) may be at least 25 deg but no more than 75 deg around the inner circumference of the stator (300) from the third air inlet port (330).

[0040] A fourth part of the exhaust stage may be defined by: a part of a period of a revolution of the rotor (200) about the rotational axis (202) when each rotor combustion chamber (210) is in fluid communication with the corresponding exhaust port (320), fluidly isolated from the corresponding stator combustion chamber (310) and in fluid communication with the third inlet port (330).

[0041] A first part of the inlet stage may be defined by a part of a period of a revolution of the rotor (200) about the rotational axis (202) when the rotor combustion chamber (210) is in fluid communication with the corresponding third air inlet port (330), fluidly isolated from the corresponding exhaust port (320) and fluidly isolated from the corresponding stator combustion chamber (310).

[0042] A second part of the inlet stage may be defined by a part of a period of a revolution of the rotor (200) about the rotational axis (202) when the rotor combustion chamber (210) is in fluid communication with the corresponding third air inlet port (330), the corresponding rotor combustion chamber (210) is fluidly isolated from thecorresponding exhaust port (320), and in fluid communication with the corresponding stator combustion chamber (310).

[0043] A third part of the inlet stage may be defined by a part of a period of a revolution of the rotor (200) about the rotational axis (202) when the rotor combustion chamber (210) is fluidly isolated from the corresponding stator combustion chamber (310), and the stator combustion chamber (310) is in fluid communication with the first air inlet port (230) and fluidly isolated from the second air inlet port (232).

[0044] A fourth part of the inlet stage may be defined by: a part of a period of a revolution of the rotor (200) about the rotational axis (202) when the corresponding rotor combustion chamber (210) is fluidly isolated from the corresponding stator combustion chamber (310), and the stator combustion chamber (310) is in fluid communication with the first air inlet port (230) and second air inlet port (232).

[0045] A fifth part of the inlet stage may be defined by: a part of a period of a revolution of the rotor (200) about the rotational axis (202) when the corresponding rotor combustion chamber (210) is fluidly isolated from the corresponding stator combustion chamber (310), and the stator combustion chamber (310) is fluidly isolated from the first air inlet port (230) and in fluid communication with the second air inlet port (232).

[0046] Each stator combustion chamber (310) may be in fluid communication with a fuel source (400) via a fuel injection system (404), the fuel injection system (404) configured to inject fuel into the stator combustion chamber (310) during the first part and / or second part of the inlet stage.

[0047] The fuel injection system (404) may comprise a first fuel injector (4041) and a second fuel injector (4042). The first fuel injector (4041) may be configured to inject fuel in a radial direction from the stator (300) towards the rotor (200). The second fuel injector (4042) may be configured to inject fuel in a direction at a tangent to the rotor (200).

[0048] The first fuel injector (4041) may be controlled to inject fuel during the first part and / or second part of the inlet stage.

[0049] A fuel ignition system (402) may be located in each stator combustion chamber (310), the fuel ignition system (402) operable to be triggered to initiate a combustion event of the combustion stage after the first fuel injector (4041) is controlled to inject fuel.

[0050] The fuel ignition system (402) may comprise a first fuel igniter (4021) mounted in a side wall (360) of the stator (300).

[0051] The fuel ignition system (402) may comprise a first fuel igniter (4021) mounted in a first side wall (360) of the stator (300) and a second fuel igniter (4022) mounted in asecond side wall (362) of the stator (300). The first side wall (360) and the second side wall (362) may define opposite sides of the stator (300). The first fuel igniter (4021) and the second fuel igniter (4022) may be operable to be triggered at the same or different times.

[0052] The second fuel injector (4042) may be operable to be controlled to inject fuel after the first fuel injector (4041) has injected fuel and after the fuel ignition system (402) has triggered.

[0053] There may be provided a method of operation of a rotary heat engine (100), the rotary heat engine (100) comprising: a rotor (200) centred on, and rotatable about, a rotational axis (202); and a stator (300) which bounds the rotor (200); wherein the rotor (200) is rotatable relative to the stator (300); the stator (300) defines a radially inner surface (304) which faces a radially outer surface (204) defined by the rotor (200); the rotor radially outer surface (204) defines a plurality of rotor combustion chambers (210) the stator radially inner surface (304) defines a plurality of stator combustion chambers (310); such that as the rotor (200) rotates relative to the stator (300), rotor-stator combustor volumes are formed each time one each of the stator combustion chambers (310) and rotor combustion chambers (210) overlap such they are in fluid communication; and the rotary heat engine (100) is configured to perform thermodynamic cycles as the rotor (200) rotates relative to the stator (300), at least part of each thermodynamic cycle occurring within each rotor-stator combustor volume formed. Each thermodynamic cycle may comprise: a combustion stage in which a combustion event develops to a first pressure condition (P1 ) ; and an exhaust stage at a second pressure condition (P2). The method may comprise the step of controlling the exhaust stage of the first rotor-stator combustor volume to start after the ignition of a combustion event in the second rotor-stator combustor volume.

[0054] There may be provided a method of operation of a heat engine (100), the rotary heat engine (100) comprising a plurality of combustor volumes. The heat engine (100) may be configured to perform thermodynamic cycles within each combustor volume formed. Each thermodynamic cycle may comprise: a combustion stage in which a combustion event develops to a first pressure condition (P1); and an exhaust stage at a second pressure condition (P2). The method may comprise the steps of controlling the exhaust stage of the first combustor volume to start after the ignition of a combustion event in the second combustor volume; controlling the first pressure condition (P1) to occur in each combustor volume and in one combustor volume at a time; and controlling the first pressure condition (P1) to occur in each combustion volume in series,with the first pressure condition (P1) in the second combustor volume occurring next in the series after the first pressure condition (P1) in the first combustor volume.

[0055] Hence there is provided a heat engine which is highly efficient, configurable for use with environmentally friendly fuels, and has a comparable or greater power output than examples of the related art.

[0056] Brief Description of the Drawings

[0057] Examples of the present disclosure will now be described with reference to the accompanying drawings, in which:

[0058] Figure 1 shows a perspective view of an assembled rotary heat engine according to the present disclosure;

[0059] Figure 2 shows an exploded view of the assembly shown in figure 1 ;

[0060] Figure 3 shows an edge view of the assembled rotary heat engine as shown in figures 1, 2;

[0061] Figure 4 shows a cross-sectional view of the heat engine along the line A-A shown in figure 3;

[0062] Figure 5 shows a perspective view of a stator of the rotary heat engine;

[0063] Figure 6 shows a perspective view of a first side of an example of a rotor of the rotary heat engine;

[0064] Figure 7 shows a perspective view of a second side of the rotor of the rotary heat engine;

[0065] Figure 8 shows a perspective top view of the rotor of the rotary heat engine; Figure 9 shows a perspective view of a rotor combustion chamber of the rotary heat engine;

[0066] Figure 10 shows a perspective sectional view of the rotor of the rotary heat engine;

[0067] Figure 11 shows a side sectional view of the rotor of the rotary heat engine; Figure 12 shows a radial sectional view of the rotor of the rotary heat engine; Figure 13 shows part (e.g. side plates) of a housing of the rotary heat engine;Figures 14 to 67 illustrate stages of operation of the rotary heat engine according to the present disclosure;

[0068] Figure 68 shows a representation of variation of pressure in a combustor volume of a rotary heat engine (Mean Effective Pressure by Angle of Rotation);

[0069] Figure 69 shows a representation of variation of pressure in a combustor volume during operation of the rotary heat engine of the present disclosure (contiguous Combustion Mean Effective Pressure by Angle of Rotation); and

[0070] Figure 70 shows a perspective top view of an alternative rotor example to that shown in figure 8.

[0071] Detailed Description

[0072] The present disclosure relates to a heat engine 100. In particular, the present disclosure relates to a rotary heat engine 100. The heat engine 100 of the present disclosure may be configured as an internal combustion engine. The heat engine 100 of the present disclosure may be configured to be operable to be powered by a combustible fuel, for example a fluid (i.e. gas or liquid) fuel, including, but not limited to, ammonia hydrogen or hydrocarbon based fuels (e.g. petrol, diesel, liquefied petroleum gas (LPG), methane, bio-fuels), synthetic fuels (e.g. “e-fuel”), town gas and / or a blend of fluid fuels, for example hydrogen and a hydrocarbon based fuel.

[0073] The heat engine 100 of the present disclosure may be incorporated into a vehicle to drive and power the vehicle. For example, as shown in figures 2, 3 the heat engine 100 may comprise an output shaft 802 (i.e. a power offtake shaft) configured to be coupled to a vehicle powertrain. Additionally, or alternatively the output shaft 802 of the heat engine 100 may be operable to power an electricity generator which in turn powers an electrical drive motor of a vehicle. The heat engine 100 of the present disclosure may also form part of an electricity generation plant, operable to drive electricity generators. The heat engine 100 of the present disclosure may be used in any application where a conventional internal combustion engine may be used, for example in land-based applications (e.g. vehicles or static structures), watercraft and aircraft.

[0074] Figures 1 to 13 illustrate examples of the structure of the heat engine 100 of the present disclosure. Figures 14 to 66 illustrate stages of operation of the rotary heat engine 100 examples. Some features of the engine are omitted from some of the drawings. For example, features of the igniter 402, fuel injector 404, and pipe workassociated with the exhaust ports 320 and the third air inlet ports 330 are omitted from some of the drawings. However, it should be understood that although these details are not shown in the figures, it should be assumed their presence (or some appropriate functional alternative) may be implicit.

[0075] Figure 1 shows a perspective view of the rotary heat engine 100. Figure 2 shows an exploded view of part of the assembly shown in Figure 1. Figure 3 shows an edge view of the assembled rotary heat engine 100.

[0076] As shown in figure 1, the rotary heat engine 100 comprises a housing 700. The housing 700 comprises a first housing side wall 702 and a second housing side wall 704. An example of these first and second housing side walls 702, 704 is shown in isolation in figure 13. The first housing side wall 702 is spaced apart from the second housing side wall 704, with a stator 300 therebetween. The stator 300 is coupled to, and fixed relative to, the first housing side wall 702 and the second housing side wall 704.

[0077] As shown in figure 2, the heat engine 100 further comprises a rotor 200 centred on, and rotatable about, a rotational axis 202. The rotor 200 may be configured as a flywheel. As shown in figure 2, the stator 300 bounds (i.e. surrounds, encircles) the rotor 200. That is to say, the stator 300 is radially outward of the rotor 200. Put another way, the stator 300 and the rotor 200 may be concentrically arranged around the rotational axis 202, with the rotor 200 being radially inward of the stator 300.

[0078] The rotor 200 is rotatable relative to the stator 300 about the rotational axis 202. The rotor 200 may be carried on a support shaft 800. The rotor 200 may be coupled to the support shaft 800, and the support shaft 800 and the rotor 200 may be rotatable about the rotational axis 202 together. The power offtake 802 may extend from and / or be coupled to the support shaft 800. For example, the power offtake 802 may extend from and / or be coupled to either end of the support shaft 800 or be coupled indirectly to the support shaft 800 via a gearing.

[0079] The rotor 200 and the support shaft 800 may be centred on the rotational axis 202. The first housing side wall 702 may be spaced apart from the second housing side wall 704 along the rotational axis 202 by the rotor 200 and the stator 300. That is to say, the rotor 200 and the stator 300 may be located between the first housing side wall 702 and the second housing side wall 704. Put another way, the first housing side wall 702 may be axially spaced apart from the second housing side wall 704 along the rotational axis 202 by the rotor 200 and the stator 300.

[0080] Each of the first housing side wall 702 and the second housing side wall 704 may be in sealing engagement with the stator 300.The rotor 200 is rotatable relative to each of the first housing side wall 702 and the second housing side wall 704. A first clearance may be maintained between the first housing side wall 702 and a first side 215 of the rotor 200, and a second clearance may be maintained between the second housing side wall 704 and a second side 217 of the rotor 200 so that the rotor 200 is rotatable relative to each of the first housing side wall 702 and the second housing side wall 704.

[0081] The first housing side wall 702 and the second housing side wall 704 are coupled to the stator 300 in such a way, and configured, to physically constrain the stator 300 from expanding radially. For example (as shown in figure 2) a recess 710 may be provided in the first housing side wall 702 and the second housing side wall 704 within which a part of the stator 300 (for example a radially outer rim 350) is located. Alternatively, and additionally the first housing side wall 702 and the second housing side wall 704 may be coupled to the stator 300 laterally by clamping fixings bolts, studs or the like. The first housing side wall 702 and the second housing side wall 704 may be coupled to the stator 300 by any conventional means. Dowls, pins and such like may be used to achieve alignment between the stator 300 and the housing side walls 702, 704.

[0082] A side wall inlet port 708 may be provided in the first housing side wall 702 and / or the second housing side wall 704. The external side of the side wall inlet port 708 (i.e. the inlet) is configured for fluid communication with a source of air 600. The source of air 600 may be the local environment (e.g. at atmospheric pressure) or a pressurised air source. The supply of pressurised air may be a compressor. That is to say, the pressurised air may be provided by a compressor. The compressor may be coupled to or spaced apart from the housing 700 and connected by tubes / pipes etc. The compressor may be of any conventional kind (for example an axial or centrifugal compressor).

[0083] The heat engine 100 may further comprise a coolant which reduces the temperature of the fluid (e.g. air) prior to delivery to the side wall inlet ports(s) 708. The heat engine 100 may further comprise an air cooler which reduces the temperature of the air prior to delivery to the third air inlet port 330. Cooling the air may improve volumetric efficiency of the heat engine 100.

[0084] Figure 4 shows a cross-sectional view of the heat engine 100 along the line A-A shown in figure 3. Figure 5 shows a perspective view of the stator 300. As can be seen in figures 4, 5 the stator 300 defines a radially inner surface 304.

[0085] Figure 6 shows a perspective view of a first side of a first example of a rotor 200. Figure 7 shows a perspective view of part of a second side of a second example of therotor 200. As can be seen in figures 2, 6, 7 the rotor 200 comprises a radially outer surface 204.

[0086] As shown in figure 4, when the rotor 200 and stator 300 are assembled the radially inner surface 304 of the stator 300 faces the radially outer surface 204 of the rotor 200.

[0087] As shown in figures 4, 6, 7, the rotor 200 may comprise a support structure 207 which extends from a hub 211 to a radially outer rim 213. The radially outer rim 213 defines the radially outer surface 204 of the rotor 200. The hub 211 may be coupled to the support shaft 800. The hub 211 may be coupled to the support shaft 800 such that they are fixed relative to one another and hence are rotatable with one another. In other examples the hub 211 may be supported on the support shaft 800 by a bearing arrangement such that the rotor 200 is rotatable relative to the support shaft 800.

[0088] As shown in the figures, the support structure 207 may be provided as a solid disc or as a disc with cut outs (for example to reduce weight).

[0089] In other examples, not shown, the support structure 207 may comprise spokes which extend from the hub 211 to the radially outer rim 213. The spokes may be spaced apart from one another to define spaces therebetween.

[0090] The radially outer surface 204 of the rotor 200 defines (i.e. is provided with) a plurality of rotor combustion chambers 210, each having a leading edge 212 and a trailing edge 214. The rotor combustion chamber leading edge 212 and the rotor combustion chamber trailing edge 214 are so termed because when the rotor 200 is rotating the leading edge 212 precedes the trailing edge 214.

[0091] The stator radially inner surface 304 defines (i.e. is provided with) a plurality of stator combustion chambers 310 having a leading edge 312 and a trailing edge 314. The stator combustion chamber leading edge 312 and the stator combustion chamber trailing edge 314 are so termed because when the rotor 200 is rotating, the leading edge 212 of each rotor combustion chamber 210 passes the leading edge 312 of each stator combustion chamber 310 before it passes the trailing edge 314 of each stator combustion chamber 310.

[0092] In the examples shown in the figures there are provided three rotor combustion chambers 210 (labelled as the first rotor combustion chamber RC1, the second rotor combustion chamber RC2 and the third rotor combustion chamber RC3) and two stator combustion chambers 310 (labelled as the first stator combustion chamber SC1 and the second stator combustion chamber SC2). In the example shown in the figuresthe two stator combustion chambers 310 (SC1, SC2) are provided diametrically opposite one another (i.e. 180 degrees apart around the circumference of the stator 300).

[0093] In other examples, not shown, there may be provided a different number of rotor combustion chambers 210 and stator combustion chambers 310. For example, there may be provided four rotor combustion chambers 210 and three stator combustion chambers 310, five rotor combustion chambers 210 and four stator combustion chambers 310, or six rotor combustion chambers 210 and five stator combustion chambers 310.

[0094] The number of rotor combustion chambers 210 may not be equal to the number of stator combustion chambers 310. That is to say, either the number of rotor combustion chambers 210 may exceed the number of stator combustion chambers 310 or the number of stator combustion chambers 310 may exceed the number of rotor combustion chambers 210.

[0095] In an example in which the number of rotor combustion chambers 210 provided is N, the number of stator combustion chambers 310 provided may be N+1. In an example in which the number of stator combustion chambers 310 is N, the number of rotor combustion chambers 210 may be N+1.

[0096] In some examples there may be provided an even number of rotor combustion chambers 210 and an odd number of stator combustion chambers 310. Alternatively, there may be provided an odd number of rotor combustion chambers 210 and an even number of stator combustion chambers 310.

[0097] In some examples there may be provided an even number of rotor combustion chambers 210 and an even number of stator combustion chambers 310.

[0098] In some examples there may be provided an odd number of rotor combustion chambers 210 and an odd number of stator combustion chambers 310.

[0099] The rotor combustion chambers 210 may be equally (e.g. evenly) distributed around the circumference of the rotor 200. The stator combustion chambers 310 may be equally (e.g. evenly) distributed around the circumference of the stator 300.

[0100] Each rotor combustion chamber 210 is aligned with each stator combustion chamber 310 on a common circumferential path centred on the rotational axis 202 such that each rotor combustion chamber 210 is in fluid communication with each stator combustion chamber 310 during a revolution of the rotor 200 about the rotational axis 202. That is to say, each rotor combustion chamber 210 is aligned with each stator combustion chamber 310 on a common circumferential path centred on the rotationalaxis 202 such that each rotor combustion chamber 210 overlaps each stator combustion chamber 310 for a part of a revolution of the rotor 200 about the rotational axis 202.

[0101] Each rotor combustion chamber 210 is provided as a recess 206 (e.g. a cavity) extending along part, but not all, of the rotor radially outer surface 204.

[0102] Each stator combustion chamber 310 is provided as a recess 306 (e.g. cavity) which extends along part, but not all, of the stator radially inner surface 304.

[0103] Each rotor recess 206 is open on a side facing the stator 300. Each stator recess 306 is open on a side facing the rotor 200.

[0104] Each rotor combustion chamber 210 extends radially inwardly into the rotor 200 at the leading edge 212 to define a rotor step 216 with a leading edge depth RDIe, each rotor combustion chamber 210 reducing in depth towards their trailing edge 214. That is to say, the depth RDIe of each of the rotor combustion chamber 210 at the leading edge 212 is greater than the depth RDte of each rotor combustion chamber 210 at their trailing edge 214.

[0105] Each rotor combustion chamber 210 may be defined by a rotor surface base wall 218 which faces the stator 300 and extends from the leading edge 212 to the trailing edge 214 of the rotor combustion chamber 210 to define a rotor combustion chamber surface 220 extending at least part of the way from the leading edge 212 to the trailing edge 214 of the rotor combustion chamber 210.

[0106] The rotor combustion chamber 210 may be defined by a rotor surface base wall 218 which faces the stator 300 and extends from the radially innermost point of the rotor step 216 to the trailing edge 214 to define a rotor combustion chamber surface 220 extending at least part of the way from the radially innermost point of the rotor step 216 to the trailing edge 214.

[0107] In both examples the rotor combustion chamber surface 220 may be convex. Each stator combustion chamber 310 may extend radially outwardly into the stator 300 at the leading edge 312 to define a stator step 316 with a leading edge depth SDIe, each stator combustion chamber 310 reducing in depth towards the trailing edge 314. The depth SDIe of each of the stator combustion chamber 310 at the leading edge 312 is greater than the depth SDte of each stator combustion chamber 310 at the trailing edge 314.

[0108] Each stator combustion chamber 310 may be defined by a stator surface base wall 318 which faces the rotor 200 and extends from the stator combustion chamber leading edge 312 to the stator combustion chamber trailing edge 314. The stator surface base wall 318 may define a surface 319 extending at least part of the way from the statorcombustion chamber leading edge 312 to the stator combustion chamber trailing edge 314. The stator surface base wall surface 319 may be concave.

[0109] Each stator combustion chamber 310 may be defined by a stator surface base wall 318 which faces the rotor 200 and extends from the radially outermost point of the stator step 316 at the stator combustion chamber leading edge 312 to the stator combustion chamber trailing edge 314. The stator surface base wall 318 may define a concave surface 319 extending from the stator combustion chamber leading edge 312 to the stator combustion chamber trailing edge 314.

[0110] In the example shown in figure 5, the stator combustion chamber surface 319 comprises a first section 311 which extends from the stator combustion chamber leading edge 312 at the inner surface of the stator 300 to define the stator step 316, and a second section 313 which extends at an angle (for example perpendicular or an alternative angle) to the first section 311 , and extends from the first section 311 towards the trailing edge 314. By way of non-limiting example, and as shown in the figures, the stator combustion chamber surface 319 may define a wedge shape.

[0111] Each rotor combustion chamber 210 may extend at least 25 deg, but no more than 70 deg, around the outer circumference of the rotor 200. Each rotor combustion chamber 210 may extend (i.e. between the rotor combustion chamber leading edge 212 and the rotor combustion chamber trailing edge 214) at least 25 deg, but no more than 70 deg, around the outer circumference of the rotor 200.

[0112] Each stator combustion chamber 310 may extend at least 15 deg, but no more than 35 deg, around the inner circumference of the stator 300. Each stator combustion chamber 310 may extend (i.e. between the stator combustion chamber leading edge 312 and the stator combustion chamber trailing edge 314) at least 15 deg, but no more than 35 deg, around the inner circumference of the stator 300.

[0113] As shown in figures 2, 6, 7 a rotor combustion chamber wall 290 may extend from the rotor combustion chamber leading edge 212 to the rotor combustion chamber trailing edge 214 on both sides of each rotor combustion chamber 210 to thereby define the transverse extent of each rotor combustion chamber 210.

[0114] As illustrated in figure 12, a first labyrinth seal 292 may be provided at the lateral edges of the rotor 200 which extends around the circumference of the rotor 200, extending over the radial land 222 (e.g. tip) of each rotor combustion chamber wall 290.

[0115] The outer circumference of the rotor 200 may be defined by a first layer of a first material with a low coefficient of thermal expansion. The outer circumference of the rotor 200 may be provided by a first layer of a first material with a low coefficient of thermalexpansion. That is to say, the material which defines / provides the radially outer surface 204 of the rotor 200 may be provided as a first layer of a first material with a lower coefficient of thermal expansion than the material of the remainder of the rotor 200 which is radially inward of the first layer of the first material.

[0116] Hence the radially outer rim 213 of the rotor 200 may comprise, at least in part, a first material with a low coefficient of thermal expansion. The radially outer rim 213 of the rotor 200 may comprise the first layer of the first material with a first coefficient of thermal expansion and a second layer of a second material (which may be the same material as the support structure 207 or different to the material of the support structure 207) which has a second coefficient of thermal expansion, the first coefficient of thermal expansion being substantially / significantly less than the second coefficient of thermal expansion. The first layer of the first material may be provided radially outwards of the second layer of the second material.

[0117] The first material 264 with a low coefficient of thermal expansion may be nickel steel, for example an alloy comprising 1 to 20% Cobalt and / or 25 to 40% Nickel.

[0118] The second material may be a metal (for example steel).

[0119] In other examples, the rim 213, rim layers and / or support structure 207 of the rotor 200 may be formed of and / or comprise other materials with suitable properties, which, by way of non-limiting example, may be metal, metallic alloys and / or ceramics.

[0120] The rotor 200 and / or stator 300 may be made of the first material (e.g. with a low coefficient of thermal expansion).

[0121] As shown in figure 5, a stator combustion chamber wall may extend from the stator combustion chamber leading edge 312 to the stator combustion chamber trailing edge 314 on both sides of each stator combustion chamber 310 to thereby define the transverse extent of each stator combustion chamber 310.

[0122] Each stator combustion chamber 310 is in fluid communication with a fuel source 400 via a fuel injection system 404. That is to say the part of the stator 300 which defines a stator combustion chamber 310 may be configured to mount a fuel injection system 404, or define a passage in fluid communication with a fuel injection system 404, such that fuel may be delivered to the stator combustion chamber 310.

[0123] In the examples shown in the figures there are provided two fuel injection systems 404, one for each stator combustor 310. As will be appreciated, in other examples, where three or more fuel injection systems 404 are provided, the spacing of the fuel injection systems 404 will be adapted accordingly (e.g. spaced apart by 360 / [number of fuel injection systems 404] degrees).The fuel injection system 404 may comprise a first fuel injector 4041 and a second fuel injector 4042. These may be provided as any conventional kind and arrangement of fuel injection system, for example forming a direct fuel injection system or a port fuel injection system.

[0124] The part of the stator 300 which defines a stator combustion chamber 310 may be configured to mount the first fuel injector 4041 and the second fuel injector 4042 such that fuel may be delivered to the stator combustion chamber 310 from the first fuel injector 4041 and / or the second fuel injector 4042.

[0125] As illustrated in figure 4, the first fuel injector 4041 may be mounted such that it injects fuel from / through the stator combustion chamber base wall 318.

[0126] The part of the stator 300 which defines a stator combustion chamber 310 may define a first fuel passage and may be configured to mount the first fuel injector 4041 such that fuel may be delivered to the stator combustion chamber 310 from the first fuel injector 4041 via the first fuel passage. That is to say, the first fuel injector 4041 may be in fluid communication with the first fuel passage. The first fuel passage may be located such that it opens onto the stator combustion chamber base wall 318.

[0127] As illustrated in figure 4, the second fuel injector 4042 may be mounted such that it injects fuel from / through the stator combustion chamber leading edge 312 (e.g. from the stator step 316).

[0128] The part of the stator 300 which defines a stator combustion chamber 310 may define a second fuel passage, and may be configured to mount the second fuel injector 4042 such that fuel may be delivered to the stator combustion chamber 310 from the second fuel injector 4042 via the second fuel passage. That is to say the second fuel injector 4042 may be in fluid communication with the second fuel passage. The second fuel passage may be located such that it opens onto the stator combustion chamber leading edge 312 (e.g. from the stator step 316).

[0129] The first fuel injector 4041 may be configured to inject fuel in a substantially radial direction from the stator 300 towards the rotor 200 (e.g. in a radial direction or in a direction with a radial component towards the rotor surface 204).

[0130] The second fuel injector 4042 is configured to inject fuel in a direction substantially at a tangent to the rotor 200 radially outer surface 204 (e.g. in a tangential direction or in a direction with a tangential component relative to the rotor 200).

[0131] The fuel source 400 may be provided as tank, reservoir or the like. The fuel source 400 may be pressurised. For example, a pump may be provided to deliver the fuel to the or each fuel injector 4041, 4042.The fuel source 400 may comprise a combustible fuel, for example a fluid (i.e. gas or liquid) fuel, including, but not limited to, hydrogen and hydrocarbon based fuels (e.g. petrol, diesel, liquefied petroleum gas (LPG), methane, bio-fuels), synthetic fuel (e.g. “e-fuel”), town gas and / or a blend of fluid fuels, for example hydrogen and a hydrocarbon based fuel.

[0132] A fuel ignition system 402 may be located in each stator combustion chamber 310. The fuel ignition system 402 may be configured to generate a source of heat sufficient to ignite fuel from the fuel source 400 under the temperature and pressure conditions defined by the rotary heat engine 100. The fuel ignition system 402 may be any conventional fuel ignition device, for example may comprise one or more spark plugs. The fuel ignition system 402 may comprise a laser.

[0133] In the example shown in the figures the fuel ignition system 402 comprises a first fuel igniter 4021 and a second fuel igniter 4022 for each stator combustor 310.

[0134] In an example in which only one fuel igniter 4021 is provided, it may be mounted in the side wall 360 of the stator 300.

[0135] In an example in which two fuel igniters 4021, 4022 are provided, the first fuel igniter 4021 may be mounted in a first side wall 360 of the stator 300 and the second fuel igniter 4022 may be mounted in a second side wall 362 of the stator 300. The first side wall 360 and the second side wall 362 may define opposite sides of the stator 300.

[0136] The or each fuel igniters 4021, 4022 may be mounted in the side walls 360, 362 of the stator 300 such that they extends through the stator combustion chamber wall.

[0137] The first fuel igniter 4021 and the second fuel igniter 4022 may be operable to be triggered at the same or different times.

[0138] Hence the stator 300 may comprise a first fuel injector 4041, a second fuel injector 4042 and a first fuel igniter 4021. Additionally, the stator 300 may further comprise a second fuel igniter 4022. Hence each stator combustion chamber 310 may be provided with a first fuel injector 4041 , a second fuel injector 4042 and a first fuel igniter 4021 and, in some examples, may further comprise a second fuel igniter 4022.

[0139] In examples in which a second fuel igniter 4022 is provided, the first fuel igniter 4021 and the second fuel igniter 4022 may be mounted in opposite side walls 360, 362 of the stator 300 such that they extend through opposing stator combustion chamber walls 360. That is to say, the first fuel igniter 4021 and the second fuel igniter 4022 may be mounted opposite one another, spaced apart by the stator combustion chamber 310.

[0140] As illustrated in figure 21 for the second rotor combustion chamber RC2 and the first stator combustion chamber SC1, the stator radially inner surface 304 and therotor radially outer surface 204 are configured such that when each rotor combustion chamber 210 is circumferentially offset from each stator combustion chamber 310, each rotor combustion chamber 210 and each stator combustion chamber 310 are fluidly isolated from one another (e.g. separated with the flow path between configured to prevent or inhibit flow of gas therebetween to provide an at least partial seal). For example, the clearance between the stator radially inner surface 304 and rotor radially outer surface 204 may be chosen such that fluid isolation (e.g. at least a partial seal) between a rotor combustion chamber 210 and a corresponding stator combustion chamber 310 at this stage in the cycle is achieved when a seal is created between them.

[0141] There may be provided a corresponding exhaust port 320 spaced apart from each stator combustion chamber 310 around the circumference of the stator radially inner surface 304. The exhaust port 320 may open onto the stator radially inner surface 304.

[0142] That is to say, an exhaust port 320 may be provided spaced apart from a stator combustion chamber 310 around the stator radially inner surface 304, positioned at such a distance from the stator combustion chamber 310 that as the rotor 200 rotates around the rotational axis 202 combustion will be completed, or at least sufficiently complete, by the time the rotor combustion chamber 210 is in fluid communication with the exhaust port 320.

[0143] Each rotor combustion chamber 210 extends around the circumference of the rotor radially outer surface 204 such that they span the distance between an adjacent (i.e. corresponding) stator combustion chamber 310 and exhaust port 320, for example as illustrated for the second rotor combustion chamber RC2 and the first stator combustion chamber SC1 in figure 16.

[0144] That is to say, each rotor combustion chamber 210 may extend around the circumference of the rotor radially outer surface 204 such that during a part of a period of a revolution of the rotor 200 about the rotational axis 202, the rotor combustion chamber 210 will be in fluid communication with an exhaust port 320 and the stator combustion chamber 310 which corresponds to the same stator combustion chamber 310. Hence after a combustion event when each rotor combustion chamber 210 and stator combustion chamber 310 are in fluid communication (and hence work is being done on the rotor 200 by the expanding gas due to combustion, which results in an increase in pressure), but fluidly isolated from the corresponding exhaust port 320, the rotor 200 turns to align the rotor combustion chamber 210 with the next exhaust port 320 along the inner circumference of the stator 300 such that the rotor combustion chamber 210 and stator combustion chamber 310 are both in fluid communication with the saidexhaust port 320 so that exhaust gas may be purged from the rotor combustion chamber 210 and stator combustion chamber 310 through the exhaust port 320.

[0145] As shown in figures 2, 4, 6, the rotor 200 comprises (i.e. defines) a first air inlet port 230 for communication with the air source air 600. The first air inlet port 230 opens on the rotor radially outer surface 204. That is to say, the first air inlet port 230 is provided as an aperture in the radially outer surface 204 of the rotor 200. A first air inlet port 230 is provided for each rotor combustion chamber 210.

[0146] The first air inlet port 230 is provided proximate to, but circumferentially spaced apart from, a rotor combustion chamber trailing edge 214. That is to say, a first air inlet port 230 opens onto the radially outer surface 204 of the rotor 200 and is provided spaced apart from an adjacent rotor combustion chamber trailing edge 214 along the radially outer surface 204 of the rotor 200.

[0147] That is to say, the rotor 200 may comprise a first air inlet port 230. A first air inlet port 230 may be provided proximate to, but circumferentially spaced apart from, each rotor combustion chamber trailing edge 214. Hence in examples in which a plurality of rotor combustion chambers 210 are provided (and as shown in the figures), a first air inlet port 230 may be provided proximate to, but circumferentially spaced apart from, each rotor combustion chamber trailing edge 214. The first air inlet port 230 may be configured for communication with a source of air 600. The first air inlet port 230 may open on the rotor radially outer surface 204.

[0148] Hence the first air inlet port 230 is only in fluid communication with the rotor combustion chamber 210 if both the rotor combustion chamber 210 and the first air inlet port 230 are in fluid communication with the stator combustion chamber 310 (for example as shown in figures 17, 18 with reference to the second rotor combustion chamber RC2).

[0149] As illustrated in figures 17,18 with reference to the second rotor combustion chamber RC2 and the first stator combustion chamber SC1, each first air inlet port 230 is located such that during a revolution of the rotor 200 about the rotational axis 202, for a part of a period when the end of each rotor combustion chamber 210 overlaps the corresponding stator combustion chamber 310 and the exhaust port 320, the first air inlet port 230 is in flow communication (e.g. fluid communication) with the rotor combustion chamber 210 and the respective stator combustion chamber 310, and hence the first air inlet port 230 is also in flow communication with the respective exhaust port 320 to thereby purge the respective stator combustion chamber 310.As illustrated in figures 19 to 21 with reference to the second rotor combustion chamber RC2 and the first stator combustion chamber SC1 the first air inlet port 230 is located such that during a revolution of the rotor 200 about the rotational axis 202, the first air inlet port 230 is in flow communication with each stator combustion chamber 310 for a part of a period when each rotor combustion chamber 210 is fluidly isolated from the respective stator combustion chamber 310.

[0150] As shown in figures 2, 4, 6, the rotor 200 comprises (i.e. defines) a second air inlet port 232 for communication with the source of air 600, the second air inlet port 232 being provided proximate to, but circumferentially spaced apart from, the first air inlet port 230, such that the second air inlet port 232 is circumferentially spaced apart from the respective rotor combustion chamber trailing edge 214 by the respective first air inlet port 230.

[0151] Hence the rotor 200 comprises a second air inlet port 232 for communication with the air source air 600. The second air inlet port 232 opens on the rotor radially outer surface 204. That is to say, the second air inlet port 232 is provided as an aperture in the radially outer surface 204 of the rotor 200. A second air inlet port 232 is provided for each rotor combustion chamber 210.

[0152] That is to say, the rotor 200 may comprise a second air inlet port 232. The second air inlet port 232 may be configured for communication with a source of air 600. The second air inlet port 232 may open on the rotor radially outer surface 204. The second air inlet port 232 may be circumferentially spaced apart from the first air inlet port 230 such that the second air inlet port 232 is circumferentially spaced apart from the respective rotor combustion chamber trailing edge 214 by the respective first air inlet port 230.

[0153] Since the first air inlet port 230 and second air inlet port 232 are on the radially outer surface 204 of the rotor 200, they are effectively “closed” when facing the stator radially inner surface 340.

[0154] Hence in examples in which a plurality of rotor combustion chambers 210 are provided (and as shown in the figures), a second air inlet port 232 may be circumferentially spaced apart from each first air inlet port 230 such that each second air inlet port 232 is circumferentially spaced apart from its respective rotor combustion chamber trailing edge 214 by the respective first air inlet port 230.

[0155] As illustrated in figures 21, 22 with reference to the second rotor combustion chamber RC2 and the first stator combustion chamber SC1 the second air inlet port 232 is located such that during a revolution of the rotor 200 about the rotational axis 202,the second air inlet port 232 is in flow communication with each stator combustion chamber 310 for a part of a period when the proximate rotor combustion chamber 210 is fluidly isolated from the respective stator combustion chamber 310.

[0156] As illustrated in figure 22 with reference to the second rotor combustion chamber RC2 and the first stator combustion chamber SC1 the first air inlet port 230 and the second air inlet port 232 are located such that during a revolution of the rotor 200 about the rotational axis 202, in a second sub-period of the period when each rotor combustion chamber 210 is fluidly isolated from each stator combustion chamber 310, the first air inlet port 230 is fluidly isolated from the respective stator combustion chamber 310 and the second air inlet port 232 is in flow communication with the respective stator combustion chamber 310.

[0157] As illustrated in figures 21 with reference to the second rotor combustion chamber RC2 and the first stator combustion chamber SC1 , the first air inlet port 230 and the second air inlet port 232 are located such that during a revolution of the rotor 200 about the rotational axis 202, in a first sub-period of the period when each rotor combustion chamber 210 of a rotor-stator combustor volume is fluidly isolated from each stator combustion chamber 310 of a rotor-stator combustor volume, the first air inlet port 230 and the second air inlet port 232 are in flow communication (e.g. fluid communication) with the respective stator combustion chamber 310.

[0158] As shown in figures 7, 10, 11 the first air inlet port 230 and / or the second air inlet port 232 may be provided as an outlet slot 270 which extends transversely across the rotor outer surface 204.

[0159] As illustrated in figure 7, a feed slot 272 may be provided on at least one side 215, 217 of the rotor 200 for fluid communication with the side wall inlet port 708 shown in figures 1, 2. That is to say, a feed slot 272 may be provided on the first side 215 of the rotor 200 and / or the second side 217 of the rotor 200. For example, a feed slot 272 may be provided on the first side 215 of the rim 213 of the rotor 200 and / or the second side 217 of the rim 213 of the rotor 200. The feed slot 272 may be provided as a recess which extends part, but not all, of the way around each side of the rotor 200. In the example shown, the outlet slots 270 extend radially into the rotor 200 and the outlet slots 270 are in fluid communication with the feed slot 272 via a passage (or passages) in the rotor 200.

[0160] Hence the internal side of the side wall inlet port 708 is in fluid communication with a first air inlet port 230 and a second air inlet port 232 when they pass the respective side wall inlet port 708 as the rotor 200 rotates about the rotational axis 202.As shown in figures 1, 2, there are provided two side wall inlet ports 708 diametrically opposite one another across the rotational axis 202. A side wall inlet port 708 is provided for every stator combustion chamber 310. Hence, however many stator combustion chambers 310 are provided, the same number of side wall inlet ports 708 are provided.

[0161] Each side wall inlet port 708 is provided at the same radius from the rotational axis 202 as the feed slot 272 such that, as the rotor 200 rotates, each feed slot 272 passes a side wall inlet port 708 and is temporarily in fluid communication with the side wall inlet port 708.

[0162] As illustrated in figures 23 to 44, with reference to the second rotor combustion chamber RC2, the first air inlet port 230 and the second air inlet port 232 are located such that after the second sub-period the second air inlet port 232 is fluidly isolated from the rotor combustion chamber 210.

[0163] As illustrated in figure 12, a second labyrinth seal 293 may be provided on each side of the rotor 200. Each second labyrinth seal 293 may extend around a diameter the rotor 200. Each second labyrinth seal 293 may be provided between the side of the rotor 200 and a respective housing side wall 702, 704. The second labyrinth seal 293 may extend at a smaller diameter than the first labyrinth seal 292. The feed slot 272 may be provided between the first labyrinth seal 292 and the second labyrinth seal 293.

[0164] The first labyrinth seal 292 and the second labyrinth seal 293 are configured such that air delivered to the wall inlet ports 708 is sealed between the first labyrinth seal 292 and the second labyrinth seal 293. That is to say, the first labyrinth seal 292 and the second labyrinth seal 293 are configured such that they provide a tortuous leakage path, thereby retaining air delivered to the wall inlet ports 708 between the first labyrinth seal 292 and the second labyrinth seal 293.

[0165] As shown in figures 2, 4, 5, the stator 300 comprises a third air inlet port 330 in communication with the source of air 600. The third air inlet port 330 is provided circumferentially spaced apart from the corresponding exhaust port 320. The third air inlet port 330 opens on the radially inner surface 304 of the stator 300.

[0166] That is to say, the third air inlet port 330 is provided in the stator 300 for communication with the source of air 600, and for delivery of air to each rotor combustion chamber 210 as each rotor combustion chamber 210 at least partially overlaps the third air inlet port 330 (for example, with reference to the second rotor combustion chamber RC2, as shown in figures 25 to 34). The third air inlet port 330 is located circumferentially spaced apart from the corresponding exhaust port 320 such that, as the rotor 200 rotatesabout the rotational axis 202, a rotor combustion chamber 210 is first in fluid communication with an exhaust port 320 and then in fluid communication with a third air inlet port 330.

[0167] The stator combustion chamber leading edge 312 may be at least 25 deg but no more than 75 deg around the inner circumference of the stator 300 from the third air inlet port 330. The stator combustion chamber leading edge 312 may be at least 35 deg but no more than 65 deg around the inner circumference of the stator 300 from the third air inlet port 330. The stator combustion chamber leading edge 312 may be at least 45 deg but no more than 55 deg around the inner circumference of the stator 300 from the third air inlet port 330. The stator combustion chamber leading edge 312 may be about 49 deg around the inner circumference of the stator 300 from the third air inlet port 330.

[0168] In examples where multiple stator combustion chambers 310 are provided, a third air inlet port 330 is provided spaced apart, and around the stator radially inner surface 304, from the stator combustion chamber 310. Hence each third air inlet port 330 is positioned such that as the rotor 200 rotates about the rotational axis 202, a rotor combustion chamber 210 is first in fluid communication with a stator combustion chamber 310, then in fluid communication with an exhaust port 320, and then in fluid communication with a third air inlet port 330.

[0169] In some examples, fuel injection may also be provided through the third air inlet port 330. For example, this may be desirable with fuels which require a longer mixing, evaporation and / or atomisation time prior to ignition. Hence fuel injection via the third inlet port 330 may be in addition to fuel injection via the first and second fuel injectors 4041, 4042. For such examples, the same, different or no fuel may be injected via the fuel injectors 4041, 4042.

[0170] Each first air inlet port 230 and each second air inlet port 232 are in fluid communication with the air source 600 via each side wall inlet port 708. The third air inlet port 330 may be in fluid communication with the same air source 600 as each first air inlet port 230 and each second air inlet port 232. That is to say, the third air inlet port 330 may be in fluid communication with the same air source 600 as the side wall inlet port 708, for example via pipework (not shown). The third air inlet port 330 may be in fluid communication with a different air source 600 to each first air inlet port 230 and each second air inlet port 232.

[0171] The air delivered to each first air inlet port 230, each second air inlet port 232 (i.e. delivered to the side wall inlet port 708) and each third inlet port 330 may be provided / delivered at constant pressure through at least part of the running range of theengine. That is to say, the air delivered to each first air inlet port 230, each second air inlet port 232 (i.e. delivered to the side wall inlet port 708) and each third inlet port 330 may be provided at the same / common pressure through at least part of the running range of the engine.

[0172] The system is configured such that each third air inlet port 330 is fluidly isolated from each rotor combustion chamber 210 until each rotor combustion chamber 210 overlaps each third air inlet port 330. Hence no air will enter the rotor combustion chamber 210 via the third air inlet port 330 until the rotor combustion chamber 210 at least partially overlaps the third air inlet port 330.

[0173] Hence there are provided an exhaust port 320 and a third air inlet port 330 for each stator combustion chamber 310. That is to say, there is provided a third air inlet port 330, stator combustion chamber 310 and exhaust port 320 in sequence around the radially inner surface 304 of the stator 300 which correspond with one another. In the example shown in the figures there are provided two exhaust ports 320 and two third air inlet ports 330. In the example shown in the figures the two exhaust ports 320 are provided diametrically opposite one another (i.e. 180 degrees apart around the circumference of the stator 300). In the example shown in the figures the two third air inlet ports 330 are provided diametrically opposite one another (i.e. 180 degrees apart around the circumference of the stator 300).

[0174] Each set of fuel ignition system 402, fuel injection system 404 and stator combustion chamber 310 are provided in series around the radially inner circumference 304 of the stator 300 with the exhaust port 320 and third air inlet port 330. Hence, each unit which comprises the fuel ignition system 402, fuel injection system 404 and stator combustion chamber 310 is provided between a corresponding exhaust port 320 and a third air inlet port 330 around the inner circumference 304 of the stator 300. Hence as the rotor 200 rotates, the rotor combustion chamber 210 will first be in fluid communication with the third air inlet port 330, then the unit comprising a fuel ignition system 402, fuel injection system 404 and stator combustion chamber 310, and then the exhaust port 320.

[0175] Additionally, and as shown in figures 6 to 10, there may be provided a flow mitigation feature 240 to manage fluid (e.g. gaseous combustion products or air) leaked from the rotor combustion chamber 210. That is to say, there may be provided a flow mitigation feature 240 to manage combusted fuel from the rotor combustion chamber 210. That is to say, there may be provided a flow mitigation feature 240 to manage air from the rotor combustion chamber 210. An example of this is shown in figures 6 to 11.In this example the leakage flow mitigation feature 240 comprises a leakage recess 242 (e.g. a channel) which opens at an opening 244 onto the rotor radially outer surface 204. The leakage recess 242 extends part of the way across the rotor radially outer surface 204, (e.g. part of the way from the first side 215 to the second side 216 of the rotor 200), between each rotor combustion chamber trailing edge 214 and the first air inlet port 230 on the rotor radially outer surface 204.

[0176] Additionally the leakage flow mitigation feature 240 may comprise a first circumferential recess 250 which extends along the rotor radially outer surface 204 from the leakage recess 242 towards and past the respective rotor combustion chamber 210, terminating at a first lead region 252 circumferentially spaced apart from the respective rotor combustion chamber leading edge 212. The first lead region 252 may be provided between the rotor combustion chamber leading edge 212 and the next second air inlet port 232 on the rotor 200. Hence the leakage recess 242 is spaced apart from the first lead region 252 by the rotor combustion chamber 210.

[0177] The first circumferential recess 250 may be configured such that, as the rotor 200 rotates relative to the stator 300, the first circumferential recess 250 is in flow communication with the exhaust port 320 before (e.g. in advance of, ahead of) the respective rotor combustion chamber 210.

[0178] The leakage flow mitigation feature 240 may further comprise a second circumferential recess 260 which extends along the rotor radially outer surface 204 from the leakage recess 242 towards and past the respective rotor combustion chamber 210, terminating at a second lead region 262 circumferentially spaced apart from the respective rotor combustion chamber leading edge 212 and the next second air inlet port 232 on the rotor 200. Hence the leakage recess 242 is spaced apart from the first lead region 252 by the rotor combustion chamber 210.

[0179] The second circumferential recess 260 may be configured such that, as the rotor 200 rotates relative to the stator 300, the second circumferential recess 260 is in flow communication with the exhaust port 320 before the respective rotor combustion chamber 210.

[0180] The second circumferential recess 260 is spaced apart from the first circumferential recess 250 by the respective rotor combustion chamber 210.

[0181] As illustrated in figures 10, 11, the leakage recess 242 extends from its opening 244 to a radially inner base 246. The channel formed may have a constant width along its length (as shown in figure 10).ln the example shown in figure 11, the channel may reduce in width (e.g. taper) between the opening 244 and the inner base 246 such that the wall of the channel closest to the trailing edge 214 is angled to the radial direction relative to the rotor 200, and the wall of the channel closest to the first air inlet port 230 extends in (i.e. is parallel with) the radial direction relative to the rotor. The angled wall may promote a pressure drop, thereby providing a flow path for any exhaust gas.

[0182] Hence any flow leaking past the trailing edge 214 of the rotor combustion chamber 210 will enter the leakage recess 242, the first circumferential recess 250 and / or the second circumferential recess 260 and will be exhausted to the exhaust port 320 when the first circumferential recess 250 and / or the second circumferential recess 260 are in fluid communication with the exhaust port 320.

[0183] As illustrated in an alternative example shown in figure 70 the leakage flow mitigation feature 240 may comprise a first leakage passage 1250 which extends from the leakage recess 242 towards and past the respective rotor combustion chamber 210, terminating at a first leakage aperture 1252 circumferentially spaced apart from the respective rotor combustion chamber leading edge 212. The first leakage aperture 1252 may open onto the rotor radially outer surface 204. The first leakage passage 1250 may be configured such that, as the rotor 200 rotates relative to the stator 300, the first leakage aperture 1252 is in flow communication with the exhaust port 320 before the respective rotor combustion chamber 210.

[0184] Also as illustrated in the example of figure 70, the leakage flow mitigation feature 240 may comprise a second leakage passage 1260 which extends from the leakage recess 242 towards and past the respective rotor combustion chamber 210, terminating at a second leakage aperture 1262 circumferentially spaced apart from the respective rotor combustion chamber leading edge 212. The second leakage aperture 1262 may open onto the rotor radially outer surface 204. The second leakage passage 1260 configured such that, as the rotor 200 rotates relative to the stator 300, the second leakage aperture 1262 is in flow communication with the exhaust port 320 before the respective rotor combustion chamber 210. The second leakage passage 1260 may be spaced apart from the first leakage passage 1250 by the respective rotor combustion chamber 210.

[0185] In figure 70 the first leakage passage 1250 and the second leakage passage 1260 are indicated with a dashed / broken line, indicating that the passages 1250, 1260 extend through the rotor 200 (e.g. the radially outer rim 213) from the leakage recess 242 to their respective leakage apertures 1252, 1262.ln some examples, not shown, only one of the first leakage passage 1250 or second leakage passage 1260 (their respective leakage apertures 1252, 1262) may be provided.

[0186] Hence any flow leaking past the trailing edge 214 of the rotor combustion chamber 210 will enter the leakage recess 242, the first leakage passage 1250 and / or the second leakage passage 1260 and will be exhausted to the exhaust port 320 when the first leakage aperture 1252 and / or the second leakage aperture 1262 are in fluid communication with the exhaust port 320.

[0187] That is to say, any flow leaking past the trailing edge 214 of the rotor combustion chamber 210 will enter the leakage recess 242 and then flow along the first leakage passage 1250 and / or the second leakage passage 1260 and will be exhausted via the first leakage aperture 1252 and / or the second leakage aperture 1262 (e.g. when the first leakage aperture 1252 and / or the second leakage aperture 1262 are in fluid communication with the exhaust port 320).

[0188] The rotor surface base wall 218 defines a step feature 280, which defines a “turbulence generator”. The step feature 280 extends transversely across the rotor combustion chamber 210. The step feature 280 defines a change in radial depth of the rotor combustion chamber base wall 218, defining a region where the depth of the rotor combustion chamber increases. The step feature 280 may be provided at least 50% but not more than 99% of the distance between the rotor combustion chamber leading edge 212 and the rotor combustion chamber trailing edge 214 along the circumference of the rotor 200.

[0189] As illustrated in figures 8 to 11, the distance of the rotor surface base wall 218 from the rotor radially outer surface 204 may decrease between the step feature 280 and the rotor combustion chamber trailing edge 214. The base wall 218 may define a surface 224 between the step feature 280 and the rotor combustion chamber trailing edge 214. The base wall 218 may define a convex surface 224 between the step feature 280 and the rotor combustion chamber trailing edge 214.

[0190] The trailing edge 214 defines a change in radial depth of the rotor combustion chamber base wall 218, defining a physical end of the rotor combustion chamber 210.

[0191] In operation, as flow from the combustion event passes over the step feature (turbulence generator 280), turbulent flow is generated, which forms a fluid dynamic impediment to laminar flow, hence acts as a fluid dynamic sealing feature. Any flow reaching the trailing edge 214 (which is also provided as a step feature) will be in aturbulent state, which will be amplified by the radial step out of the trailing edge 214, creating a further impediment to laminar flow from the rotor combustion chamber 210.

[0192] The heat engine 100 is configured such that as the rotor 200 rotates relative to the stator 300, rotor-stator combustor volumes are formed each time one each of the stator combustion chambers 310 and rotor combustion chambers 210 overlap such that they are in fluid communication.

[0193] Hence the rotary heat engine 100 is configured to form a plurality of combustor volumes.

[0194] The rotary heat engine 100 is configured to perform thermodynamic cycles as the rotor 200 rotates relative to the stator 300, at least part of each thermodynamic cycle occurring within each rotor-stator combustor volume formed.

[0195] As illustrated in figures 68, 69, each thermodynamic cycle comprises a combustion stage, an exhaust stage and an inlet stage.

[0196] A combustion stage may be defined as a part of the thermodynamic cycle in which a combustion event results in (e.g. develops to) a first pressure condition P1 (e.g. a power stage or high-pressure stage). The first pressure condition may be a range of pressures, for example peaking to a maximum value before falling gradually through the power phase (for example, to include a period of pressure decay).

[0197] The exhaust stage may be defined as a part of the thermodynamic cycle in which the contents (e.g. exhaust gases) exit the rotor combustion chamber 210 and stator combustion chamber 310 at a second pressure condition P2 (e.g. exhaust gas purge, which may be of ambient pressure). The second pressure condition may have a constant value.

[0198] The inlet stage may be defined as a part of the thermodynamic cycle in which air and fuel are delivered to the rotor combustion chamber 210 and the stator combustion chamber 310, which may be at a third pressure condition P3 , and which starts prior to formation of each rotor-stator combustor volume (e.g. a low-pressure stage). The third pressure condition may have a fixed value.

[0199] The first pressure condition P1 (e.g. the pressure which occurs in the combustion stage) will have a higher value than the second pressure condition P2 of the exhaust stage and a higher value than the third pressure condition P3 in the inlet stage.

[0200] The third pressure condition P3 of the inlet stage may have a higher value than the second pressure condition P2 of the exhaust stage.

[0201] The first pressure condition P1 may be at least 5 times, but no more than 300 times, greater than the second pressure condition P2.The first pressure condition P1 may be at least 5 times, but no more than 50 times, greater than the third pressure condition P3.

[0202] As illustrated in figures 16, 26, 34, 44, 52, 62, the features of the rotary heat engine 100 (including the rotor combustion chambers 210 and stator combustion chambers 310) are configured such that the exhaust stage of the first rotor-stator combustor volume starts after the ignition of a combustion event in the second rotor-stator combustor volume.

[0203] The exhaust stage of the first rotor-stator combustor volume may start before, at the same time or after the first pressure condition P1 is reached in the second rotorstator combustor volume.

[0204] Hence the arrangement of the rotor combustion chambers 210 and stator combustion chambers 310 of the heat engine 100 of the present disclosure enable contiguous combustion events as the rotor 200 rotates around the rotational axis 202 relative to the stator 300. In this context “contiguous" is taken to mean that during operation of the heat engine 100, each combustion event is followed immediately by, or slightly overlapping, a subsequent combustion event, with no time delay between consecutive combustion events.

[0205] The features of the rotary heat engine 100 of the present disclosure are configured such that the first pressure condition P1 is controlled to occur in each rotor-stator combustor volume formed and in one rotor-stator combustor volume at a time for example as illustrated in figure 69).

[0206] As illustrated in figures 14 to 67, each rotor combustion chamber 210 and stator combustion chamber 310 are configured such that as the rotor 200 rotates relative to the stator 300 the second rotor-stator combustor volume is formed after the first rotorstator combustor volume is formed. Hence more than one rotor-stator combustion volume may exist at the same time.

[0207] As illustrated in figures 14 to 67, the rotor combustion chamber 210 and stator combustion chamber 310 are configured such that as the rotor 200 rotates relative to the stator 300, the second rotor-stator combustor volume is formed before the first rotor combustion chamber 210 and first stator combustion chamber 310 forming the first rotor-stator combustor volume become fluidly isolated (i.e. separate) from one another. Hence the second rotor-stator combustor volume may be created before the trailing edge of each of the first rotor stator combustor volumes are closed to each other.

[0208] As illustrated in figures 14 to 67, the rotor combustion chamber 210 and stator combustion chamber 310 are configured such that the first rotor-stator combustorvolume and second rotor-stator combustor volume are formed in series, and the second rotor-stator combustor volume is formed next in the series after the formation of the first rotor-stator combustor volume.

[0209] As illustrated in the figures, each rotor combustion chamber 210 and each stator combustion chamber 310 has a fixed volume. Hence each rotor-stator combustor volume is a fixed volume.

[0210] The exhaust stage may be defined by four consecutive parts.

[0211] A first part of the exhaust stage is defined by a part of a period of a revolution of the rotor 200 about the rotational axis 202 when the rotor combustion chamber 210 is in fluid communication with the corresponding exhaust port 320 and the corresponding stator combustion chamber 310 of the rotor-stator combustor volume, for example as illustrated in figure 16 with respect the rotor combustion chamber 210 labelled as the second rotor combustion chamber RC2 and the stator combustion chamber 310 labelled as the first stator combustion chamber SC1.

[0212] Each first air inlet port 230 may be located such that a second part of the exhaust stage may be defined by a part of a period of a revolution of the rotor 200 about the rotational axis 202, when the rotor combustion chamber 210 overlaps the corresponding stator combustion chamber 310 of the rotor-stator combustor volume and the exhaust port 320, such that the first air inlet port 230 is in flow communication with the exhaust port 320 via the respective stator combustion chamber 310 and rotor combustion chamber 210, for example as illustrated in figures 17 to 20 with respect to the second rotor combustion chamber RC2 and first stator combustion chamber SC1.

[0213] A third part of the exhaust stage may be defined by a part of a period of a revolution of the rotor 200 about the rotational axis 202 when each rotor combustion chamber 210 is in fluid communication with the corresponding exhaust port 320 and fluidly isolated from the corresponding stator combustion chamber 310, for example as illustrated in figures 21 to 24 with respect to the second rotor combustion chamber RC2 and the first stator combustion chamber SC1.

[0214] A fourth part of the exhaust stage may be defined by a part of a period of a revolution of the rotor 200 about the rotational axis 202 when each rotor combustion chamber 210 is in fluid communication with the corresponding exhaust port 320, fluidly isolated from the corresponding stator combustion chamber 310 and in fluid communication with the third air inlet port 330, for example as illustrated in figures 25 to 27 with respect to the second rotor combustion chamber RC2 and first stator combustion chamber SC1.The inlet stage may be defined by five consecutive parts.

[0215] A first part of the inlet stage may be defined by a part of a period of a revolution of the rotor 200 about the rotational axis 202 when the rotor combustion chamber 210 is in fluid communication with the corresponding third air inlet port 330, fluidly isolated from the corresponding exhaust port 320 and fluidly isolated from the corresponding stator combustion chamber 310, for example as illustrated in figures 28 to 32 with respect to the second rotor combustion chamber RC2 and the second stator combustion chamber SC2.

[0216] A second part of the inlet stage may be defined by a part of a period of a revolution of the rotor 200 about the rotational axis 202 when the rotor combustion chamber 210 is in fluid communication with the corresponding third air inlet port 330, fluidly isolated from the corresponding exhaust port 320, and in fluid communication with the corresponding stator combustion chamber 310, for example as illustrated in figures 33 to 34 with respect to the second rotor combustion chamber RC2 and the second stator combustion chamber SC2.

[0217] The fuel injection system 404 configured to inject fuel into the stator combustion chamber (310) during the first part and / or the second part of the inlet stage, for example as illustrated in figures 32 to 34 with respect to the second rotor combustion chamber RC2 and the second stator combustion chamber SC2.

[0218] The fuel ignition system 402 operable to be triggered to initiate a combustion event of the combustion stage after the first fuel injector 4041 is controlled to inject fuel.

[0219] The second fuel injector 4042 is operable to be controlled to inject fuel after the first fuel injector 4041 has injected fuel and after the fuel ignition system 402 has been triggered, for example as illustrated in figures 35 to 39 with respect to the second rotor combustion chamber RC2 and the second stator combustion chamber SC2.

[0220] In some example modes of operation, only the second fuel injector 4042 and first fuel igniter 4041 may be controlled to operate.

[0221] In some example modes of operation, only the second fuel injector 4042 may be controlled to operate.

[0222] In some example modes of operation, only the first fuel injector 4041 may be controlled to operate.

[0223] Hence the fuel injectors 4041 , 4042 may be controlled to work in combination with each other, or controlled such that one is operated but the other is note.

[0224] The second fuel injector 4042 is operable to be controlled to inject fuel when the respective rotor combustion chamber 210 and stator combustion chamber 310 are influid communication, and the rotor combustion chamber 210 and stator combustion chamber 310 are fluidly isolated from the exhaust port 320, for example as illustrated in figures 35 to 39 with respect to the second rotor combustion chamber RC2 and the second stator combustion chamber SC2.

[0225] A third part of the inlet stage may be defined by a part of a period of a revolution of the rotor 200 about the rotational axis 202 when the rotor combustion chamber 210 is in fluid communication with the corresponding stator combustion chamber 310, and the stator combustion chamber 310 is in fluid communication with the first air inlet port 230 and fluidly isolated from the second air inlet port 232, for example as illustrated in figure 45 with respect to the second rotor combustion chamber RC2 and the second stator combustion chamber SC2.

[0226] A fourth part of the inlet stage may be defined by a part of a period of a revolution of the rotor 200 about the rotational axis 202 when the corresponding rotor combustion chamber 210 is fluidly isolated from the corresponding stator combustion chamber 310, and the stator combustion chamber 310 is in fluid communication with the first air inlet port 230 and the second air inlet port 232, for example as illustrated in figures 46 to 47 with respect to the second rotor combustion chamber RC2 and the second stator combustion chamber SC2.

[0227] A fifth part of the inlet stage may be defined by a part of a period of a revolution of the rotor 200 about the rotational axis 202 when the corresponding rotor combustion chamber 210 is fluidly isolated from the corresponding stator combustion chamber 310, and the stator combustion chamber 310 is fluidly isolated from the first air inlet port 230 and in fluid communication with the second air inlet port 232, for example as illustrated in figure 48 with respect to the second rotor combustion chamber RC2 and the second stator combustion chamber SC2.

[0228] The operation of the heat engine 100 of the present disclosure will now be described with reference to figures 14 to 67 in which there are six combustion events in series, two in each of the rotor combustion chambers RC1, RC2, RC3, and three in each of the stator combustion chambers SC1, SC2 as labelled in figures 14 to 66.

[0229] As will be appreciated, since there are examples in which there are a different number of rotor combustion chambers 210 and stator combustion chambers 310 to that shown in the figures, the precise operation of different examples will vary.

[0230] However, in all examples, the operation includes controlling the exhaust stage of a first combustor volume (e.g. when a first pair of rotor combustion chamber 210 and stator combustion chamber 310 are in fluid communication) to start after the ignitionof a combustion event in a second combustor volume (e.g. when a second pair of rotor combustion chamber 210 and stator combustion chamber 310 are in fluid communication), as illustrated in figures 16, 26, 34, 44, 52, 62.

[0231] The method may comprise the step of controlling the exhaust stage of a first combustor volume to start before, at the same time, or after, the first pressure condition P1 is reached in a second combustor volume (for example as illustrated in figure 69).

[0232] The method may comprise the step of controlling the first pressure condition P1 to occur in each combustor volume and in one combustor volume at a time, (for example as illustrated in figure 69).

[0233] The method may comprise controlling the first pressure condition P1 to occur in each combustor volume in series, with the first pressure condition P1 in the second combustor volume occurring next in the series after the first pressure condition P1 in the first combustor volume (for example as illustrated in figures 14 to 67, figures 68, 69).

[0234] Figure 14 shows a stage where the first rotor combustion chamber RC1 (fluidly isolated from the first stator combustion chamber SC1 and the second stator combustion chamber SC2) is in fluid communication with an exhaust port 320. At the same time combustion is occurring in the rotor-stator combustor volume formed by the second rotor combustion chamber RC2 and the first stator combustion chamber SC1 (which are in fluid communication with one another). Also, at the same time the third rotor combustion chamber RC3 (fluidly isolated from the first stator combustion chamber SC1 and the second stator combustion chamber SC2) is being charged with air from a third air inlet port 330 and fuel (indicated by the solid line arrow) is being injected by the first fuel injector 4041 into the second stator combustion chamber SC2.

[0235] Figure 15 shows a stage where the first rotor combustion chamber RC1 (fluidly isolated from the first stator combustion chamber SC1 and the second stator combustion chamber SC2) is in fluid communication with a third air inlet port 330 and an exhaust port 320 and hence is being purged of any residual combustion gases. At the same time combustion is occurring in the rotor-stator combustor volume formed by the second rotor combustion chamber RC2 and the first stator combustion chamber SC1 (which are in fluid communication with one another). Also, at the same time the third rotor combustion chamber RC3 and the second stator combustion chamber SC2 are in fluid communication with one another and being charged with fuel from the associated first fuel injector 4041. The associated first fuel igniter 4021 istriggered to start combustion. In examples in which a second fuel igniter 4022 is provided, the second fuel igniter 4022 may be triggered at the same time or at a later time to the first fuel igniter 4021.

[0236] Figure 16 shows combustion occurring in the rotor-stator combustor volume formed by the second rotor combustion chamber RC2 and the first stator combustion chamber SC1 (which are in fluid communication with one another), and the second rotor combustion chamber RC2 is in fluid communication with an exhaust port 320.

[0237] Figure 17 shows a stage where the third rotor combustion chamber RC3 and the second stator combustion chamber SC2 are in fluid communication with one another. Fuel (indicated by the solid line arrow) is then injected by the second fuel injector 4042 into the volume created by the third rotor combustion chamber RC3 and the second stator combustion chamber SC2. The fuel injected by the second fuel injector 4042 is ignited (e.g. by fuel igniter and / or by the fuel already burning in the volume created by the third rotor combustion chamber RC3 and the second stator combustion chamber SC2).

[0238] Figure 18 shows a stage where the first rotor combustion chamber RC1 is still in fluid communication with the third air inlet port 330 but is fluidly isolated from the exhaust port 320 and hence is being charged with air (i.e. at the third pressure condition P3). At the same time the second rotor combustion chamber RC2 is still in fluid communication with the first stator combustion chamber SC1 and the second rotor combustion chamber RC2 is in fluid communication with an exhaust port 320 and so is exhausting combustion gases. The corresponding first air inlet port 230 is in fluid communication with the first stator combustion chamber SC1 to thereby purge and charge the first stator combustion chamber SC1. Also, at the same time combustion is occurring in the volume formed by the third rotor combustion chamber RC3 and the second stator combustion chamber SC2.

[0239] Figure 19 shows a stage where the first rotor combustion chamber RC1 is still in fluid communication with the third air inlet port 330 but is fluidly isolated from the exhaust port 320 and hence is being charged with air. At the same time the second rotor combustion chamber RC2 is fluidly isolated from the first stator combustion chamber SC1 and the second rotor combustion chamber RC2 is in fluid communication with an exhaust port 320 and so is exhausting combustion gases. The corresponding first air inlet port 230 and second air inlet port 232 are in fluid communication with the first stator combustion chamber SC1 and the flow mitigationfeature 240 to further purge the first stator combustion chamber SC1 Also, at the same time combustion is occurring in the volume formed by the third rotor combustion chamber RC3 and the second stator combustion chamber SC2.

[0240] Figures 20 to 21 show stages where the first rotor combustion chamber RC1 is still in fluid communication with the third air inlet port 330 but is fluidly isolated from the exhaust port 320 and hence is being charged with air. At the same time the second rotor combustion chamber RC2 is fluidly isolated from the first stator combustion chamber SC1 and the second rotor combustion chamber RC2 is in fluid communication with an exhaust port 320 and so is exhausting combustion gases. The corresponding first air inlet port 230 and second air inlet port 232 are in fluid communication with the first stator combustion chamber SC1, but isolated from the flow mitigation feature 240, and thereby charge the first stator combustion chamber SC1. Also, at the same time combustion is occurring in the volume formed by the third rotor combustion chamber RC3 and the second stator combustion chamber SC2.

[0241] Figure 22 shows a stage where the first rotor combustion chamber RC1 is still in fluid communication with the third air inlet port 330 but is fluidly isolated from the exhaust port 320 and hence is being charged with compressed air. At the same time the second rotor combustion chamber RC2 is fluidly isolated from the first stator combustion chamber SC1, and the second rotor combustion chamber RC2 is in fluid communication with an exhaust port 320 and so is exhausting combustion gases. The second rotor combustion chamber RC2 is now fluidly isolated from the first air inlet port 230, and the corresponding second air inlet port 232 is in fluid communication with the first stator combustion chamber SC1 to thereby charge the first stator combustion chamber SC1. Also, at the same time combustion is occurring in the volume formed by the third rotor combustion chamber RC3 and the second stator combustion chamber SC2.

[0242] Figure 23 shows a stage where the first rotor combustion chamber RC1 is still in fluid communication with the third air inlet port 330 but is fluidly isolated from the exhaust port 320 and hence is being charged with air. At the same time the second rotor combustion chamber RC2 is fluidly isolated from the first stator combustion chamber SC1, and the second rotor combustion chamber RC2 is in fluid communication with an exhaust port 320 and so is exhausting combustion gases. The second rotor combustion chamber RC2 is now fluidly isolated from the first air inlet port 230 and the corresponding second air inlet port 232. Also, at the same timecombustion is occurring in the volume formed by the third rotor combustion chamber RC3 and the second stator combustion chamber SC2.

[0243] Figure 24 shows a stage where the first rotor combustion chamber RC1 is still in fluid communication with the third air inlet port 330, and fluidly isolated from the first stator combustion chamber SC1 but is fluidly isolated from the exhaust port 320 and hence is being charged with air. At the same time the second rotor combustion chamber RC2 is fluidly isolated from the first stator combustion chamber SC1, and the second rotor combustion chamber RC2 is in fluid communication with an exhaust port 320 and so is exhausting combustion gases. The second rotor combustion chamber RC2 is fluidly isolated from the first air inlet port 230 and the corresponding second air inlet port 232. Also, at the same time combustion is occurring in the volume formed by the third rotor combustion chamber RC3 and the second stator combustion chamber SC2.

[0244] Figure 25 shows a stage where the first rotor combustion chamber RC1 is still in fluid communication with the third air inlet port 330, in fluid communication with the first stator combustion chamber SC1 but is fluidly isolated from the exhaust port 320 and hence is being charged with air. At the same time the second rotor combustion chamber RC2 is fluidly isolated from the first stator combustion chamber SC1, and the second rotor combustion chamber RC2 is in fluid communication with a third inlet port 330 and an exhaust port 320 and so is exhausting combustion gases. The second rotor combustion chamber RC2 is fluidly isolated from the first air inlet port 230 and the corresponding second air inlet port 232. Also, at the same time combustion is occurring in the volume formed by the third rotor combustion chamber RC3 and the second stator combustion chamber SC2.

[0245] Figure 26 shows a stage in which the first rotor combustion chamber RC1 and the first stator combustion chamber SC1 are in fluid communication with one another and being charged with fuel from the associated first fuel injector 4041. The associated first fuel igniter 4021 is triggered to start combustion. In examples in which a second fuel igniter 4022 is provided, the second fuel igniter 4022 may be triggered at the same time or at a later time to the first fuel igniter 4021. At the same time the second rotor combustion chamber RC2 (fluidly isolated from the first stator combustion chamber SC1 and the second stator combustion chamber SC2) is in fluid communication with a third air inlet port 330 and an exhaust port 320 and hence is being purged of any residual combustion gases. Also, at the same time combustion is ending in the rotorstator combustor volume formed by the third rotor combustion chamber RC3 andthe second stator combustion chamber SC2 (which are in fluid communication with one another), and the second rotor combustion chamber RC2 is in fluid communication with an exhaust port 320.

[0246] Figure 27 shows a stage in which the first rotor combustion chamber RC1 and the first stator combustion chamber SC1 are in fluid communication with one another and being charged with fuel from the associated first fuel injector 4041 while combustion progresses. At the same time the second rotor combustion chamber RC2 (fluidly isolated from the first stator combustion chamber SC1 and the second stator combustion chamber SC2) is in fluid communication with a third air inlet port 330 and an exhaust port 320 and hence is being purged of any residual combustion gases. Also, at the same time combustion has ended in the rotor-stator combustor volume formed by the third rotor combustion chamber RC3 and the second stator combustion chamber SC2 (which are in fluid communication with one another), and the second rotor combustion chamber RC2 is in fluid communication with an exhaust port 320.

[0247] Figure 28 shows a stage where the first rotor combustion chamber RC1 and the first stator combustion chamber SC1 are in fluid communication with one another. Fuel (indicated by the solid line arrow) is then injected by the second fuel injector 4042 into the volume created by the first rotor combustion chamber RC1 and the first stator combustion chamber SC1. The fuel injected by the second fuel injector 4042 is ignited by a fuel igniter 4021 and / or the fuel already burning in the volume created by the first rotor combustion chamber RC1 and the first stator combustion chamber SC1.

[0248] At the same time the second rotor combustion chamber RC2 (fluidly isolated from the first stator combustion chamber SC1 and the second stator combustion chamber SC2) is in fluid communication with a third air inlet port 330 and is isolated from the exhaust port 320. Also, at the same time combustion has ended in and the third rotor combustion chamber RC3 and the second stator combustion chamber SC2 are fluidly isolated from one another, and the third rotor combustion chamber RC3 is in fluid communication with an exhaust port 320.

[0249] Figure 29 shows a stage where combustion is occurring in the first rotor combustion chamber RC1 and the first stator combustion chamber SC1. At the same time, the second rotor combustion chamber RC2 (fluidly isolated from the first stator combustion chamber SC1 and the second stator combustion chamber SC2) is still in fluid communication with the third air inlet port 330, but is fluidly isolated from the exhaust port 320 and hence is being charged with air. At the same time the third rotor combustion chamber RC3 is fluidly isolated from the first stator combustionchamber SC1, and is in fluid communication with an exhaust port 320 and so is exhausting combustion gases. The corresponding first air inlet port 230 and second air inlet port 232 are in fluid communication with the second stator combustion chamber SC2 to thereby charge the second stator combustion chamber SC2.

[0250] Figures 30 to 32 show stages where combustion is occurring in the first rotor combustion chamber RC1 and the first stator combustion chamber SC1. At the same time, the second rotor combustion chamber RC2 is still in fluid communication with the third air inlet port 330, but is fluidly isolated from the exhaust port 320 and hence is being charged with air. At the same time the third rotor combustion chamber RC3 is fluidly isolated from the second stator combustion chamber SC2, and is in fluid communication with an exhaust port 320 and so is exhausting combustion gases.

[0251] With regards to the second stator combustion chamber SC2 and third rotor combustion chamber RC3, in figure 29 the corresponding first air inlet port 230 and second air inlet port 232 are in fluid communication with the second stator combustion chamber SC2 to thereby charge the second stator combustion chamber SC2. In figure 30 the corresponding first air inlet port 230 is fluidly isolated from the second stator combustion chamber SC2 and the third rotor combustion chamber RC3, and the second air inlet port 232 is in fluid communication with the second stator combustion chamber SC2 to thereby charge the second stator combustion chamber SC2. In figures 31, 32 the corresponding first air inlet port 230 and the second air inlet port 232 are fluidly isolated from the second stator combustion chamber SC2 and the third rotor combustion chamber RC3.

[0252] As shown in the figures, after this stage the process continues and repeats as the rotor combustion chambers 210 cycle around past the stator combustion chambers 310 in turn.

[0253] As indicated with arrows, there may be flow via the leakage flow mitigation feature 240 to the corresponding exhaust port 320 (for example as illustrated in figures 14 to 20 with respect to the second rotor combustion chamber RC2 and first stator combustion chamber SC1; as illustrated in figures 19 to 28 with respect to the third rotor combustion chamber RC3 and the second stator combustion chamber SC2; as illustrated in figures 29 to 38 with respect to the first rotor combustion chamber RC1 and first stator combustion chamber SC1 , and so on as the rotor 200 rotates.) Table 1, Table 2, Table 3 (below) define the state of each of the rotor combustion chambers RC1, RC2, RC3 and stator combustion chambers SC1, SC2 throughout a complete rotation of the rotor 200 relative to the stator 300.As can been seen, combustion occurs continuously throughout the rotation of the rotor, switching between being in the first stator combustion chamber SC1 and the second stator combustion chamber SC2.

[0254]

[0255] Table 1: Combustion stage, exhaust stage and inlet stage of rotary heat engine (figures 14 to 32)

[0256]

[0257] Table 2: combustion stage, exhaust stage and inlet stage of rotary heat engine (figures 33 to 50)

[0258]

[0259] Table 3: combustion stage, exhaust stage and inlet stage of rotary heat engine (figures 51 to 67)

[0260] Hence, in the example shown, in a full rotation of the rotor 200 about the rotational axis 202 there would be six combustion events in series (rather than simultaneously),two in each of the rotor combustion chambers RC1, RC1, RC3. In the example shown, in a full rotation of the rotor 200 about the rotational axis 202 there would be a maximum of six combustion events in series. That is to say, the combustion events may occur in the following order:

[0261] Combustion event 1 in the first rotor combustion chamber RC1 and the first stator combustion chamber SC1 (figures 26 to 33);

[0262] Combustion event 2 in the second rotor combustion chamber RC2 and the second stator combustion chamber SC2 (figures 33 to 43);

[0263] Combustion event 3 in the third rotor combustion chamber RC3 and the first stator combustion chamber SC1 (figures 43 to 51);

[0264] Combustion event 4 in the first rotor combustion chamber RC1 and the second stator combustion chamber SC2 (figures 51 to 61);

[0265] Combustion event 5 in the second rotor combustion chamber RC2 and the first stator combustion chamber SC1 (figures 61 to 15); and

[0266] Combustion event 6 in the third rotor combustion chamber RC3 and the second stator combustion chamber SC2 (figures 15 to 27);

[0267] That is to say, an example of the rotary engine 100 may be operated by controlling combustion events to occur in each rotor combustion chamber 210 and each stator combustion chamber 310 when a rotor combustion chamber 210 and a stator combustion chamber 310 are in fluid communication and controlling combustion events to occur in sequential pairings of each rotor combustion chamber 210 and each stator combustion chamber 310. The rotor combustion chamber 210, stator combustion chamber 310, inlet ports and exhaust ports are configured and arranged relative to one another such the combustion events occur contiguously, in that each combustion event is followed immediately by, or slightly overlapping, or before, a subsequent combustion event, with no time delay between consecutive combustion events.

[0268] Put another way, an example of the rotary engine 100 may be operated by controlling combustion events to occur when a rotor combustion chamber 210 and a stator combustion chamber 310 are in fluid communication, and since there are a different number of rotor combustion chambers 210 and stator combustion chambers 310, combustion occurs with each pairing of a rotor combustion chamber 210 and a stator combustion chamber 310, in turn, as the rotor 200 rotates.

[0269] Hence there is provided a heat engine which is highly efficient, configurable for use with environmentally friendly fuels, and has a comparable, or greater, power output than examples of the related art.These advantages are achieved by the nested rotary arrangement of the equipment of the present disclosure (i.e. the rotor being within the stator) and the arrangement and relative sizing of the combustors in the rotor and stator which enables contiguous combustion events as the rotor rotates. This enables a higher torque than a conventional internal combustion engine and other rotary engines.

[0270] The arrangement of the present disclosure enables contiguous combustion under full power or lean-burn operation, improving energy density, reducing cyclic losses, and enhancing fuel efficiency relative to examples of the related art. This is in part achieved with an exhaust port configured for precise alignment with the rotor chamber to enable efficient gas evacuation and minimise back-pressure effects.

[0271] The heat engine of the present disclosure also provides a system with enhanced thermodynamic efficiency, reduced emissions and operational flexibility.

[0272] In the example shown in the figures, such an arrangement achieves six ignition firings per revolution. Hence at full power the engine of the present disclosure delivers constant smooth power output.

[0273] The arrangement of the present disclosure may purge the exhaust in both the stator and rotor combustion chambers with compressed air thereby ensuring that each cycle within a combustion chamber achieves high volumetric efficiency without the risk of preignition.

[0274] Additionally, the configuration of the apparatus which provides sealing / fluid isolation (e.g. at least partial sealing), for example using tight tolerances, control of expansion of the rotor and stator expansion, and / or the use of labyrinth technology between the rotor and the stator and between the rotor and the housing side walls is effective in mitigating losses through leakage. The rotor combustion chamber of the heat engine of the present disclosure also provides additional leakage management features towards and at the trailing edge to thereby maintain a high mean effective pressure (MEP).

[0275] Lubrication between the rotor and stator may not be required, and neither may a water-cooling system be required, which (in such examples) would avoid the need for pumps and passageways in the apparatus to deliver the lubrication and cooling fluid.

[0276] The heat engine of the present disclosure is adaptable to operate on a wide range of liquified and / or fluid fuels, for example (but not limited to) petrol, diesel, Liquid Petroleum Gas, ammonia, methane and hydrogen.Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

[0277] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive.

[0278] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0279] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMS1. A rotary heat engine (100) comprising:a rotor (200) centred on, and rotatable about, a rotational axis (202); and a stator (300) which bounds the rotor (200);wherein the rotor (200) is rotatable relative to the stator (300);the stator (300) defines a radially inner surface (304) which faces a radially outer surface (204) defined by the rotor (200);the rotor radially outer surface (204) defines a plurality of rotor combustion chambers (210)the stator radially inner surface (304) defines a plurality of stator combustion chambers (310);such that as the rotor (200) rotates relative to the stator (300), rotor-stator combustor volumes are formed each time one each of the stator combustion chambers (310) and rotor combustion chambers (210) overlap such they are in fluid communication; andthe rotary heat engine (100) is configured to perform thermodynamic cycles as the rotor (200) rotates relative to the stator (300), at least part of each thermodynamic cycle occurring within each rotor-stator combustor volume formed; wherein each thermodynamic cycle comprises:a combustion stage in which a combustion event results in a first pressure condition (P1); andan exhaust stage at a second pressure condition (P2);the rotary heat engine (100) being configured such that:the exhaust stage of the first rotor-stator combustor volume starts after the ignition of a combustion event in the second rotor-stator combustor volume; andwherein the rotor combustion chamber (210) and stator combustion chamber (310) are configured such that the first rotor-stator combustor volume and second rotor-stator combustor volume are formed in series, and the second rotor-stator combustor volume is formed next in the series after the formation of the first rotor-stator combustor volume.

2. A rotary heat engine (100) as claimed in claim 1 wherein the rotary heat engine (100) is configured such that the first pressure condition (P1) is controlled to occurin each rotor-stator combustor volume formed and in one rotor-stator combustor volume at a time.

3. A rotary heat engine (100) as claimed in claim 1 or claim 2 wherein each rotor combustion chamber (210) and stator combustion chamber (310) are configured such that as the rotor (200) rotates relative to the stator (300):the second rotor-stator combustor volume is formed after the first rotorstator combustor volume is formed.

4. A rotary heat engine (100) as claimed in claim 3 wherein the rotor combustion chamber (210) and stator combustion chamber (310) are configured such that as the rotor (200) rotates relative to the stator (300), the second rotor-stator combustor volume is formed before the first rotor combustion chamber and first stator combustion chamber forming the first rotor-stator combustor volume become fluidly isolated from one another.

5. A rotary heat engine (100) as claimed in any one of claims 1 to 4 wherein each thermodynamic cycle comprises an inlet stage at a third pressure condition (P3) which starts prior to formation of each rotor-stator combustor volume.

6. A rotary heat engine (100) as claimed in claim 5 wherein:the first pressure condition (P1) has a higher value than the second pressure condition (P2) and the third pressure condition (P3); andthe third pressure condition (P3) has a higher value than the second pressure condition (P2).

7. A rotary heat engine (100) as claimed in claim 6 wherein:the first pressure condition (P1) is at least 5 times, but no more than 300 times, greater than the second pressure condition (P2);the first pressure condition (P1) is at least 5 times, but no more than 50 times, greater than the third pressure condition (P3).

8. A rotary heat engine (100) as claimed in any one of claims 1 to 7 wherein each rotor combustion chamber (210) and each stator combustion chamber (310) has a fixed volume.

9. A rotary heat engine (100) as claimed in any one of claims 1 to 8 wherein the number of rotor combustion chambers (210) is not equal to the number of stator combustion chambers (310).

10. A rotary heat engine (100) as claimed in any one of claims 1 to 9 wherein there are provided:three rotor combustion chambers (210) and two stator combustion chambers (310);four rotor combustion chambers (210) and three stator combustion chambers (310);five rotor combustion chambers (210) and four stator combustion chambers (310); orsix rotor combustion chambers (210) and five stator combustion chambers (310).

11. A rotary heat engine (100) as claimed in any one of claims 1 to 10 wherein: each rotor combustion chamber (210) has a leading edge (212) and a trailing edge (214);each stator combustion chamber (310) has a leading edge (312) and a trailing edge (314); andeach rotor combustion chamber (210) is defined by a rotor surface base wall (218) which faces the stator (300) and extends from the leading edge (212) to the trailing edge (214) of the rotor combustion chamber (210) to define a rotor combustion chamber surface (220) extending at least part of the way from the leading edge (212) to the trailing edge (214) of the rotor combustion chamber (210).

12. A rotary heat engine (100) as claimed in claim 11 wherein the rotor (200) comprises a first air inlet port (230);the first air inlet port (230) is configured for communication with a source of air (600);the first air inlet port (230) is provided proximate to, but circumferentially spaced apart from, each rotor combustion chamber trailing edge (214); andthe first air inlet port (230) opens on the rotor radially outer surface (204).

13. A rotary heat engine (100) as claimed in claim 12 comprising a leakage flow mitigation feature (240) wherein the leakage flow mitigation feature (240) comprises:a leakage recess (242) which opens at an opening (244) onto the rotor radially outer surface (204) and extends part of the way across the rotor radially outer surface (204) between each rotor combustion chamber trailing edge (214) and the first air inlet port (230) on the rotor radially outer surface (204); and a first circumferential recess (250) which extends along the rotor radially outer surface (204) from the leakage recess (242) towards and past the respective rotor combustion chamber (210), terminating at a first lead region (252) circumferentially spaced apart from the respective rotor combustion chamber leading edge (212);the first circumferential recess (250) configured such that, as the rotor (200) rotates relative to the stator (300), the first circumferential recess (250) is in flow communication with the exhaust port (320) before the respective rotor combustion chamber (210).

14. A rotary heat engine (100) as claimed in claim 13 wherein the leakage flow mitigation feature (240) comprises:a second circumferential recess (260) which extends along the rotor radially outer surface (204) from the leakage recess (242) towards and past the respective rotor combustion chamber (210), terminating at a second lead region (262) circumferentially spaced apart from the respective rotor combustion chamber leading edge (212);the second circumferential recess (260) configured such that, as the rotor (200) rotates relative to the stator (300), the second circumferential recess (260) is in flow communication with the exhaust port (320) before the respective rotor combustion chamber (210); andthe second circumferential recess (260) is spaced apart from the first circumferential recess (250) by the respective rotor combustion chamber (210).

15. A rotary heat engine (100) as claimed in claim 12 comprising a leakage flow mitigation feature (240) wherein the leakage flow mitigation feature (240) comprises:a leakage recess (242) which opens at an opening (244) onto the rotor radially outer surface (204) and extends part of the way across the rotor radially outer surface (204) between each rotor combustion chamber trailing edge (214) and the first air inlet port (230) on the rotor radially outer surface (204); and a first leakage passage (1250) which extends from the leakage recess (242) towards and past the respective rotor combustion chamber (210), terminating at a first leakage aperture (1252) circumferentially spaced apart from the respective rotor combustion chamber leading edge (212);the first leakage passage (1250) configured such that, as the rotor (200) rotates relative to the stator (300), the first leakage aperture (1252) is in flow communication with the exhaust port (320) before the respective rotor combustion chamber (210).

16. A rotary heat engine (100) as claimed in claim 15 wherein the leakage flow mitigation feature (240) comprises:a second leakage passage (1260) which extends from the leakage recess (242) towards and past the respective rotor combustion chamber (210), terminating at a second leakage aperture (1262) circumferentially spaced apart from the respective rotor combustion chamber leading edge (212);the second leakage passage (1260) configured such that, as the rotor (200) rotates relative to the stator (300), the second leakage aperture (1262) is in flow communication with the exhaust port (320) before the respective rotor combustion chamber (210); andthe second leakage passage (1260) is spaced apart from the first leakage passage (1250) by the respective rotor combustion chamber (210).

17. A rotary heat engine (100) as claimed in any one of claims 13 to 16 wherein: the leakage recess (242) extends from its opening (244) to a radially inner base (270), and reduces in width between the opening (270) and the inner base (270).

18. A rotary heat engine (100) as claimed in any one of claims 11 to 17 wherein the rotor surface base wall (218) defines a step feature (280) which extends transversely across the rotor combustion chamber (210),the step feature (280) being provided at least 50% but not more than 99% of the distance between the rotor combustion chamber leading edge (212) and the rotor combustion chamber trailing edge (214);the distance of the rotor surface base wall (218) from the rotor radially outer surface (204) decreasing between the step feature (280) and the rotor combustion chamber trailing edge (214), and defining a surface (224) therebetween.

19. A rotary heat engine (100) as claimed in any one of claims 1 to 18 wherein there is provided a corresponding exhaust port (320) which opens onto the stator radially inner surface (304), and is spaced apart from each stator combustion chamber (310) around the circumference of the stator radially inner surface (304); andeach rotor combustion chamber (210) extends around the circumference of the rotor radially outer surface (204) such that they span the distance between the corresponding stator combustion chamber (310) and exhaust port (320) such that a first part of the exhaust stage is defined by:a part of a period of a revolution of the rotor (200) about the rotational axis (202) when the rotor combustion chamber (210) is in fluid communication with the corresponding exhaust port (320) and the corresponding stator combustion chamber (310).

20. A rotary heat engine (100) as claimed in claim 19 when dependent on claim 12 wherein each first air inlet port (230) is located such that a second part of the exhaust stage is defined by:a part of a period of a revolution of the rotor (200) about the rotational axis (202), when the rotor combustion chamber (210) overlaps the corresponding stator combustion chamber (310) and the exhaust port (320), such that the first air inlet port (230) is in flow communication with the exhaust port (320) via the respective stator combustion chamber (310) and rotor combustion chamber (210).

21. A rotary heat engine (100) as claimed in claim 20 wherein a third part of the exhaust stage is defined by:a part of a period of a revolution of the rotor (200) about the rotational axis (202) when each rotor combustion chamber (210) is in fluid communication with thecorresponding exhaust port (320) and fluidly isolated from the corresponding stator combustion chamber (310).

22. A rotary heat engine (100) as claimed in any one of claims 20, 21 wherein the rotor (200) comprises a second air inlet port (232) for communication with the source of air (600), the second air inlet port (232) being provided proximate to, but circumferentially spaced apart from, the first air inlet port (230), such that the second air inlet port (232) is circumferentially spaced apart from the respective rotor combustion chamber trailing edge (214) by the respective first air inlet port (230).

23. A rotary heat engine (100) as claimed in claim 22 wherein the second air inlet port (232) is located such that during a revolution of the rotor (200) about the rotational axis (202), the second air inlet port (232) is in flow communication with each stator combustion chamber (310) for a part of a period when the proximate rotor combustion chamber (210) is fluidly isolated from the respective stator combustion chamber (310).

24. A rotary heat engine (100) as claimed in claims 22, 23 wherein the first air inlet port (230) and the second air inlet port (232) are located such that during a revolution of the rotor (200) about the rotational axis (202):in a first sub-period of the period when the rotor combustion chamber (210) is fluidly isolated from the stator combustion chamber (310), the first air inlet port (230) and the second air inlet port (232) are in flow communication with the respective stator combustion chamber (310); andin a second sub-period of the period when the rotor combustion chamber (210) is fluidly isolated from the stator combustion chamber (310), the first air inlet port (230) is fluidly isolated from the respective stator combustion chamber (310) and the second air inlet port (232) is in flow communication with the respective stator combustion chamber (310).

25. A rotary heat engine (100) as claimed in any one of the preceding claims wherein the rotor combustion chambers (210) are equally spaced around the rotor (200) and each extend at least 25 deg, but no more than 70 deg, around the outer circumference of the rotor (200);the stator combustion chambers (310) are equally spaced around the stator (300) and each stator combustion chamber (310) extends at least 15 deg, but no more than 35 deg, around the inner circumference of the stator (300); andthe stator combustion chamber trailing edge (314) is at least 15 deg but no more than 60 deg around the inner circumference of the stator (300) from the exhaust port (320).

26. A rotary heat engine (100) as claimed in claim 25 wherein the stator (300) comprises a third air inlet port (330) for communication with the source of air (600), the third air inlet port (330) being provided circumferentially spaced apart from the corresponding exhaust port (320); andthe stator combustion chamber leading edge (312) is at least 25 deg but no more than 75 deg around the inner circumference of the stator (300) from the third air inlet port (330).

27. A rotary heat engine (100) as claimed in claim 26 when dependent on claim 18 wherein a fourth part of the exhaust stage is defined by:a part of a period of a revolution of the rotor (200) about the rotational axis (202) when each rotor combustion chamber (210) is in fluid communication with the corresponding exhaust port (320), fluidly isolated from the corresponding stator combustion chamber (310) and in fluid communication with the third inlet port (330).

28. A rotary heat engine (100) as claimed in claim 27 when dependent on claim 7 wherein a first part of the inlet stage is defined by:a part of a period of a revolution of the rotor (200) about the rotational axis (202) when the rotor combustion chamber (210) is in fluid communication with the corresponding third air inlet port (330), fluidly isolated from the corresponding exhaust port (320) and fluidly isolated from the corresponding stator combustion chamber (310).

29. A rotary heat engine (100) as claimed in claim 28 wherein a second part of the inlet stage is defined by:a part of a period of a revolution of the rotor (200) about the rotational axis (202) when the rotor combustion chamber (210) is in fluid communication with the corresponding third air inlet port (330), the corresponding rotor combustion chamber (210) is fluidly isolated from the corresponding exhaust port (320), and in fluid communication with the corresponding stator combustion chamber (310).

30. A rotary heat engine (100) as claimed in claim 29 when dependent on claim 21 wherein a third part of the inlet stage is defined by:a part of a period of a revolution of the rotor (200) about the rotational axis (202) when the rotor combustion chamber (210) is fluidly isolated from the corresponding stator combustion chamber (310), andthe stator combustion chamber (310) is in fluid communication with the first air inlet port (230) and fluidly isolated from the second air inlet port (232).

31. A rotary heat engine (100) as claimed in claim 29 or claim 30 wherein a fourth part of the inlet stage is defined by:a part of a period of a revolution of the rotor (200) about the rotational axis (202) when the corresponding rotor combustion chamber (210) is fluidly isolated from the corresponding stator combustion chamber (310), andthe stator combustion chamber (310) is in fluid communication with the first air inlet port (230) and second air inlet port (232).

32. A rotary heat engine (100) as claimed in claim 31 wherein a fifth part of the inlet stage is defined by:a part of a period of a revolution of the rotor (200) about the rotational axis (202) when the corresponding rotor combustion chamber (210) is fluidly isolated from the corresponding stator combustion chamber (310), andthe stator combustion chamber (310) is fluidly isolated from the first air inlet port (230) and in fluid communication with the second air inlet port (232).

33. A rotary heat engine (100) as claimed in any one of claims 31, 32 when dependent on claim 24 wherein each stator combustion chamber (310) is in fluid communication with a fuel source (400) via a fuel injection system (404), the fuel injection system (404) configured to inject fuel into the stator combustion chamber (310) during the first part and / or second part of the inlet stage.

34. A rotary heat engine (100) as claimed in claim 33 wherein the fuel injection system (404) comprises a first fuel injector (4041) and a second fuel injector (4042);the first fuel injector (4041) is configured to inject fuel in a radial direction from the stator (300) towards the rotor (200);the second fuel injector (4042) is configured to inject fuel in a direction at a tangent to the rotor (200).

35. A rotary heat engine (100) as claimed in claim 33 or claim 34 wherein:the first fuel injector (4041) is controlled to inject fuel during the first part and / or second part of the inlet stage.

36. A rotary heat engine (100) as claimed in any one of the preceding claims wherein a fuel ignition system (402) is located in each stator combustion chamber (310), the fuel ignition system (402) operable to be triggered to initiate a combustion event of the combustion stage after the first fuel injector (4041) is controlled to inject fuel.

37. A rotary heat engine (100) as claimed in claim 36 wherein the fuel ignition system (402) comprises:a first fuel igniter (4021) mounted in a side wall (360) of the stator (300); or a first fuel igniter (4021) mounted in a first side wall (360) of the stator (300) and a second fuel igniter (4022) mounted in a second side wall (362) of the stator (300), the first side wall (360) and a second side wall (362) defining opposite sides of the stator (300), the first fuel igniter (4021) and the second fuel igniter (4022) being operable to be triggered at the same or different times.

38. A rotary heat engine (100) as claimed in claim 37 when dependent on claim 32 wherein:the second fuel injector (4042) is operable to be controlled to inject fuel after the first fuel injector (4041) has injected fuel and after the fuel ignition system (402) has triggered.

39. A method of operation of a rotary heat engine (100), the rotary heat engine (100) comprising:a rotor (200) centred on, and rotatable about, a rotational axis (202); and a stator (300) which bounds the rotor (200);wherein the rotor (200) is rotatable relative to the stator (300);the stator (300) defines a radially inner surface (304) which faces a radially outer surface (204) defined by the rotor (200);the rotor radially outer surface (204) defines a plurality of rotor combustion chambers (210)the stator radially inner surface (304) defines a plurality of stator combustion chambers (310);such that as the rotor (200) rotates relative to the stator (300), rotor-stator combustor volumes are formed each time one each of the stator combustion chambers (310) and rotor combustion chambers (210) overlap such they are in fluid communication; andthe rotary heat engine (100) is configured to perform thermodynamic cycles as the rotor (200) rotates relative to the stator (300), at least part of each thermodynamic cycle occurring within each rotor-stator combustor volume formed; wherein each thermodynamic cycle comprises:a combustion stage in which a combustion event develops to a first pressure condition (P1); andan exhaust stage at a second pressure condition (P2);whereby the method comprises:controlling the exhaust stage of the first rotor-stator combustor volume to start after the ignition of a combustion event in the second rotor-stator combustor volume; andcontrolling the rotor combustion chamber (210) and stator combustion chamber (310) so that the first rotor-stator combustor volume and second rotor-stator combustor volume are formed in series, and the second rotor-stator combustor volume is formed next in the series after the formation of the first rotor-stator combustor volume.

40. A method of operation of a heat engine (100), the rotary heat engine (100) comprising a plurality of combustor volumesthe heat engine (100) being configured to perform thermodynamic cycles within each combustor volume formed;wherein each thermodynamic cycle comprises:a combustion stage in which a combustion event develops to a first pressure condition (P1); andan exhaust stage at a second pressure condition (P2);whereby the method comprises the steps of:controlling the exhaust stage of the first combustor volume to start after the ignition of a combustion event in the second combustor volume;controlling the first pressure condition (P1) to occur in each combustor volume and in one combustor volume at a time; andcontrolling the first pressure condition (P1) to occur in each combustion volume in series, with the first pressure condition (P1) in the second combustor volume occurring next in the series after the first pressure condition (P1) in the first combustor volume.

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