Turbine-based combined ramjet engine and aircraft

Abstract

The turbine-based combined ramjet engine is characterized in that the turbine-based combined ramjet engine comprises an inner culvert channel, and the inner culvert channel is provided with a core diffuser, a core engine, a low-pressure turbine, an afterburner and an injection spray pipe; the core diffuser, the core machine, the low-pressure turbine, the afterburner and the injection spray pipe are sequentially arranged in the airflow direction. The outer culvert channel surrounds the radial outer side of the inner culvert channel, the outer culvert channel is provided with a mode selection valve, an outer culvert diffuser, a ramjet combustion chamber and a single-side expansion spray pipe, and the mode selection valve, the outer culvert diffuser, the ramjet combustion chamber and the single-side expansion spray pipe are sequentially arranged in the airflow direction; the mode selection valve is used for controlling opening and closing of the outer culvert channel; and the supersonic through-flow fan is arranged on the upstream sides of the inner culvert channel and the outer culvert channel.

Description

Technical Field

[0001] The present application relates to a turbine-based combined ramjet engine and an aircraft. Background Art

[0002] For near-space high-speed aircraft with conventional horizontal takeoff and landing and reusability, the flight envelope is very wide, the operating altitude range can be 0 to 30km or higher, the Mach number range can be 0 to 4.0 and above, and it has the characteristics of strong survivability, long flight time, and fast response speed. The wide flight envelope puts forward extremely high requirements for the power system, such as ground zero-speed start, high unit thrust and specific impulse, compact structure, and reusability. The existing single type of engine is difficult to meet the power development needs of near-space aircraft.

[0003] The turbine-based combined cycle (TBCC) engine is a combined power engine that integrates the thermal cycle and structural layout of a turbine engine and a ramjet engine. It takes into account the advantages of the horizontal take-off and landing of a turbine engine and the high-speed cruising of a ramjet engine. In the parallel layout, the ramjet engine and the turbine engine each have independent airflow channels, combustion chambers, and tail nozzle convergence sections, but share the tail nozzle expansion section and the air inlet, and the structure is not compact enough. Compared with the parallel turbine-based combined cycle (TBCC) engine, the tandem turbine-based combined cycle (TBCC) engine has a compact structure and small additional resistance, but the overall structure is complex and has greater difficulty in technical implementation. Both the parallel and tandem types have the disadvantage of a long and heavy air inlet.

[0004] Variable cycle engine (VCE) is a gas turbine engine that changes its thermodynamic cycle by changing the geometry, size or position of some engine components. The variable cycle can change the engine cycle parameters, such as the compression ratio, turbine inlet temperature, air flow and bypass ratio, so that the engine has good comprehensive performance under various flight and working conditions, but the variable cycle engine cannot significantly improve the flight envelope of the engine. Summary of the invention

[0005] The present application aims to propose a turbine-based combined ramjet engine to at least solve or alleviate one problem or defect existing in the background technology.

[0006] The embodiment of the present application provides a turbine-based combined ramjet engine, which includes:

[0007] An inner channel, wherein the inner channel is provided with a core diffuser, a core engine, a low-pressure turbine, an afterburner and an ejector nozzle, wherein the core diffuser, the core engine, the low-pressure turbine, the afterburner and the ejector nozzle are sequentially arranged along an airflow direction;

[0008] An outer duct, the outer duct is surrounded by the radially outer side of the inner duct, the outer duct is provided with a mode selection valve, an outer duct diffuser, a ramjet combustion chamber and a unilateral expansion nozzle, the mode selection valve, the outer duct diffuser, the ramjet combustion chamber and the unilateral expansion nozzle are arranged in sequence along the airflow direction, and the mode selection valve is used to control the opening and closing of the outer duct;

[0009] A supersonic through-flow fan is arranged on the upstream side of the inner channel and the outer channel.

[0010] In at least one possible embodiment, the core engine includes a high-pressure compressor, a main combustion chamber and a high-pressure turbine, and the main combustion chamber is located between the high-pressure compressor and the high-pressure turbine.

[0011] In at least one possible implementation, the high-pressure compressor and the high-pressure turbine are connected to a high-pressure shaft, and the high-pressure compressor is driven by the high-pressure turbine.

[0012] In at least one possible implementation, the supersonic through-flow fan and the low-pressure turbine are connected to a low-pressure shaft, and the supersonic through-flow fan is driven by the low-pressure turbine.

[0013] In at least one possible embodiment, the ramjet engine has a turbofan mode. In the turbofan mode, the mode selection valve is opened, the outer duct and the supersonic through-flow fan are connected, the main combustion chamber is ignited and operated, and the ramjet combustion chamber and the afterburner combustion chamber are not ignited and operated.

[0014] In at least one possible embodiment, the ramjet engine has a turbojet mode. In the turbojet mode, the mode selection valve is closed, the outer duct and the supersonic through-flow fan are blocked, the main combustion chamber is ignited, and the ramjet combustion chamber and the afterburner combustion chamber are not ignited.

[0015] In at least one possible embodiment, the ramjet engine has a ramjet mode. In the ramjet mode, the mode selection valve is opened, the outer duct and the supersonic through-flow fan are connected, the ramjet combustion chamber is ignited and operated, and the main combustion chamber and the afterburner combustion chamber are not ignited and operated.

[0016] In at least one possible embodiment, during the process of converting the ramjet engine from the turbojet mode to the ramjet mode, the afterburner is ignited to increase the Mach number of the ramjet engine, and then the mode selection valve is opened, the ramjet combustion chamber is ignited, and after the combustion in the ramjet combustion chamber is stabilized, the afterburner and the main combustion chamber are sequentially shut down.

[0017] In at least one possible embodiment, the core diffuser can adjust the capture area, the throat area of ​​the ejector nozzle can be adjusted, the inlet guide vanes of the high-pressure compressor can be adjusted, and the inlet guide vanes of the low-pressure turbine can be adjusted.

[0018] The present application also proposes an aircraft, which includes a turbine-based combined ramjet engine according to any one of the above technical solutions.

[0019] By adopting the above technical solution and setting a supersonic flow fan, there is no need to expand the supersonic flow into a subsonic flow at the windward side of the fan, so there is no need to set a long and bulky air inlet duct, making the air inlet duct shorter and lighter. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the principle configuration of a turbine-based combined ramjet engine according to an embodiment of the present application is shown.

[0021] Figure 2 An aerodynamic configuration diagram of a turbine-based combined ramjet engine according to an embodiment of the present application is shown.

[0022] Description of Reference Numerals

[0023] 1 Supersonic flow fan

[0024] 2 Core Diffuser

[0025] 3 External diffuser

[0026] 4 Core engine 41 High pressure compressor 42 Main combustion chamber 43 High pressure turbine

[0027] 5 Low-pressure turbine

[0028] 6 Afterburner

[0029] 7 Ramjet combustion chamber

[0030] 8 Single-sided expansion nozzle

[0031] 9 Ejector nozzle

[0032] P mode selector valve DETAILED DESCRIPTION

[0033] In order to more clearly explain the above-mentioned purposes, features and advantages of the present application, the specific implementation methods of the present application are described in detail in this section in conjunction with the accompanying drawings. In addition to the various implementation methods described in this section, the present application can also be implemented in other different ways. Without violating the spirit of the present application, those skilled in the art can make corresponding improvements, deformations and substitutions, so the present application is not limited by the specific embodiments disclosed in this section. The scope of protection of the present application shall be subject to the claims.

[0034] like Figure 1 and Figure 2 As shown, an embodiment of the present application proposes a turbine-based combined ramjet engine (hereinafter referred to as the engine), which includes a supersonic throughflow fan 1 (STFF), a core diffuser 2, an outer diffuser 3, a core engine 4, a low-pressure turbine 5, an afterburner 6, a ramjet combustion chamber 7, a single-sided expansion nozzle 8 and an ejector nozzle 9.

[0035] The core engine 4 includes a high-pressure compressor 41, a main combustion chamber 42 and a high-pressure turbine 43. The high-pressure compressor 41, the main combustion chamber 42 and the high-pressure turbine 43 may be arranged in sequence along the airflow direction.

[0036] The engine is formed with an inner channel and an outer channel, and the outer channel surrounds the radial outer side of the inner channel.

[0037] The mode selection valve P, the duct diffuser 3, the ramjet combustion chamber 7 and the unilateral expansion nozzle 8 may be located in the duct passage. In the airflow direction, the mode selection valve P, the duct diffuser 3, the ramjet combustion chamber 7 and the unilateral expansion nozzle 8 are arranged in sequence. The mode selection valve P may be arranged on the downstream side of the supersonic through-flow fan 1. The mode selection valve P is used to control the connection and closing of the supersonic through-flow fan 1 with the duct passage, thereby adjusting the mode of the engine.

[0038] The core diffuser 2, the high pressure compressor 41, the main combustion chamber 42, the high pressure turbine 43, the low pressure turbine 5, the afterburner 6 and the ejector nozzle 9 can be located in the inner channel. In the airflow direction, the core diffuser 2, the high pressure compressor 41, the main combustion chamber 42, the high pressure turbine 43, the low pressure turbine 5, the afterburner 6 and the ejector nozzle 9 are arranged in sequence.

[0039] The high-pressure compressor 41 and the high-pressure turbine 43 are connected to the high-pressure shaft, and the high-pressure compressor 41 can be driven by the high-pressure turbine 43. The main combustion chamber 42 is located between the high-pressure compressor 41 and the high-pressure turbine 43. The supersonic through-flow fan 1 and the low-pressure turbine 5 are connected to the low-pressure shaft, and the supersonic through-flow fan 1 can be driven by the low-pressure turbine 5. The low-pressure shaft and the high-pressure shaft are concentrically arranged, and the low-pressure shaft can be sleeved on the high-pressure shaft, and the low-pressure shaft and the high-pressure shaft can rotate independently relative to the housing of the engine.

[0040] Compared with the parallel turbine-based combined cycle engine, the engine of the present application arranges the ramjet combustion chamber 7 and the afterburner combustion chamber 6 separately in the outer channel and the inner channel, and the ramjet combustion does not affect the inner channel and has little impact on the core engine 4.

[0041] The unilateral expansion nozzle 8 is arranged at the outlet of the culvert channel, and the unilateral expansion nozzle 8 is used to discharge the airflow flowing through the culvert channel.

[0042] The outer duct diffuser 3 is used to diffuse the supersonic airflow, and the airflow passing through the outer duct can enter the ramjet combustion chamber 7 after diffusion.

[0043] The core diffuser 2 is used to diffuse the supersonic airflow, and the airflow passing through the inner channel can enter the high-pressure compressor 41 after diffusion. The core diffuser 2 has an adjustable capture area mechanism, so that the airflow at the outlet of the supersonic through-flow fan 1 can smoothly enter the high-pressure compressor 41, so that the engine can match the flow capacity and optimize the engine performance.

[0044] The ejector nozzle 9 is arranged at the outlet of the inner channel, and is used to discharge the airflow flowing through the inner channel. The throat area of ​​the ejector nozzle 9 can be adjusted, and by adjusting the throat area of ​​the ejector nozzle 9, the back pressure of the low-pressure turbine 5 can be controlled, thereby adjusting the intake flow rate of the supersonic through-flow fan 1.

[0045] The core diffuser 2 can adjust the capture area so that the outlet airflow of the supersonic through-flow fan 1 can smoothly enter the high-pressure compressor 41, which is beneficial to flow matching and performance optimization.

[0046] The inlet guide vanes of the high-pressure compressor 41 can be adjusted, so that the intake flow and power of the core engine 4 of the engine can be adjusted as needed.

[0047] The inlet guide vanes of the low-pressure turbine 5 can be adjusted, so that the intake flow and power of the low-pressure turbine 5 can be adjusted as needed.

[0048] Supersonic Through-Flow Fan (STFF) means: when the aircraft is flying at supersonic speed, the inlet flow of the engine fan is supersonic, the supersonic through-flow fan 1 is a single-stage fan, and the inlet of the supersonic through-flow fan 1 can be conical. The supersonic through-flow fan 1 can achieve a pressure ratio that a conventional fan can only achieve through two stages. Compared with conventional engines, the supersonic through-flow fan 1 does not require a long and bulky inlet to expand the supersonic inlet flow into a subsonic flow at the windward surface of the fan, so that a shorter, lighter, and less aerodynamically dragged conical inlet can be used. The supersonic through-flow fan 1 can have a lower friction drag coefficient and a higher lift-to-drag ratio. The resistance of the engine inlet is reduced, so that compared with conventional engines, its thrust is increased and fuel consumption is reduced in the non-afterburning state during supersonic cruise.

[0049] By adopting a supersonic through-flow fan 1 to make the outer duct have ramjet combustion conditions, the aircraft can operate in the range of Mach numbers 0 to 4 using a single engine.

[0050] The engine of the present application has three combustion chambers, namely a main combustion chamber 42 , an afterburner chamber 6 and a ramjet combustion chamber 7 .

[0051] The engine of the present application can operate in three modes, namely, turbofan mode, turbojet mode and ramjet mode.

[0052] (Turbofan mode)

[0053] When the aircraft is flying at a low Mach number (it can be understood that the low Mach number here refers to a specific engine, for example, a low Mach number can refer to less than or equal to 40% of the maximum Mach number. For example, if the maximum Mach number of the engine can reach Mach 4, then Mach 1 is a low Mach number, but if the maximum Mach number of the engine can reach Mach 2, then Mach 1 does not belong to a low Mach number), the mode selection valve P is opened, and the outer duct is connected to the supersonic flow fan 1. The main combustion chamber 42 is ignited, and the ramjet combustion chamber 7 of the outer duct is not ignited, and only the outer duct is used to exhaust gas. The airflow of the outer duct can be sonic, and the engine working mode is a turbofan mode.

[0054] By adjusting the capture area of ​​the core diffuser 2, adjusting the guide vane angle of the high-pressure compressor 41, adjusting the inlet guide vane of the low-pressure turbine 5, and adjusting the throat area of ​​the ejector nozzle 9, the air flow rate can be matched and the engine performance can be optimized. The turbofan mode is mainly used in the subsonic cruise state of the aircraft.

[0055] (Turbojet mode)

[0056] When the aircraft needs to increase the flight speed, the engine can switch to turbojet mode. The mode selection valve P closes the outer channel to allow the airflow to enter the inner channel. The main combustion chamber 42 ignites and the afterburner chamber 6 does not ignite, and the engine enters turbojet mode.

[0057] (Punching mode)

[0058] When the aircraft needs to continue to increase the flight speed, the afterburner 6 needs to be opened to further increase the Mach number. For example, when the speed reaches 2.5 to 3 Mach, the mode selection valve P is opened to allow the airflow to flow through the outer duct and the ramjet combustion chamber 7 is ignited. At this time, the three combustion chambers work together, and the engine has continuous thrust. After the ramjet combustion chamber 7 burns stably, the afterburner 6 and the main combustion chamber 42 are extinguished in turn. The outer duct diffuser 3 can allow the airflow at the outlet of the supersonic through-flow fan 1 to pass through the diffuser to the ramjet combustion chamber 7 for combustion. At this time, the engine is in a high Mach operating state (it can be understood that the high Mach here is for a specific engine, for example, the high Mach number can refer to greater than or equal to 70% of the maximum Mach number).

[0059] When switching from ramjet mode to turbojet mode, the main combustion chamber 42 and the afterburner chamber 6 are ignited successively. After the combustion in the main combustion chamber 42 and the afterburner chamber 6 is stable, the ramjet combustion chamber 7 is extinguished, and the mode selection valve P closes the outer passage to allow the airflow to enter the inner passage.

[0060] By switching between turbofan mode, turbojet mode, and ramjet mode, the flight speed of the engine can be gradually increased, with a wider speed range, and variable cycle can be achieved in a wider speed range. There is no thrust interruption during the switching of the three modes, and the control method of switching modes is simple, which reduces the difficulty and cost of mode switching.

[0061] Aircraft have different requirements for engine performance under different flight conditions. The engine of the present application can realize adaptive adjustment of flow rate, pressure ratio and bypass ratio by adjusting the capture area of ​​the core diffuser 2, adjusting the guide vane angle of the high-pressure compressor 41, adjusting the inlet guide vane of the low-pressure turbine 5, and adjusting the throat area of ​​the ejector nozzle 9, and enable the engine to have the working ability from Mach number 0 to 4.

[0062] It should be understood that at least some aspects or features of the above-mentioned implementation modes, embodiments or examples may be appropriately combined.

[0063] It is understood that in the present application, when the number of parts or components is not particularly limited, the number may be one or more, and the multiple here means two or more. For the case where the number of parts or components shown in the drawings and / or described in the specification is a specific number such as two, three, four, etc., the specific number is usually exemplary and not restrictive, and it can be understood as multiple, that is, two or more, but this does not mean that the present application excludes the case of one.

[0064] In the present application, unless otherwise clearly stated or limited, the terms such as "install", "assemble", "assemble", "connect", "connect", "couple", "link", "abut", "connect", "interconnect", "intercommunication", "conduction", "fixation", "fastening" and the like should be understood in a broad sense, for example, they can be direct or indirect. For example, regarding connection, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly stated or limited. For example, regarding connectivity / conduction, it can be direct connectivity / conduction, or it can be indirect connectivity / conduction via an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0065] In the present application, unless otherwise clearly stated or limited, a component disposed on / installed on / located on / accommodated on / placed in, within, inside, etc. another component may be any of the following two situations: a part or most of the one component is located in the other component; and the one component is completely accommodated in the other component.

[0066] Although the present application is described in detail using the above-mentioned embodiments, it is obvious to those skilled in the art that the present application is not limited to the embodiments described in this specification. The present application can be modified and implemented as a modified embodiment without departing from the subject matter and scope of the present application as determined by the claims. Therefore, the description in this specification is for the purpose of illustration and does not have any restrictive meaning for the present application.

Claims

1. A turbine-based combined ramjet engine, characterized in that: It includes: An inner channel, wherein the inner channel is provided with a core diffuser (2), a core engine (4), a low-pressure turbine (5), an afterburner (6) and an ejector nozzle (9), wherein the core diffuser (2), the core engine (4), the low-pressure turbine (5), the afterburner (6) and the ejector nozzle (9) are arranged in sequence along an airflow direction; An outer duct, the outer duct is surrounded by the radially outer side of the inner duct, the outer duct is provided with a mode selection valve (P), an outer duct diffuser (3), a ramjet combustion chamber (7) and a single-sided expansion nozzle (8), the mode selection valve (P), the outer duct diffuser (3), the ramjet combustion chamber (7) and the single-sided expansion nozzle (8) are arranged in sequence along the airflow direction, and the mode selection valve (P) is used to control the opening and closing of the outer duct; A supersonic through-flow fan (1), wherein the supersonic through-flow fan (1) is arranged on the upstream side of the inner channel and the outer channel.

2. The turbine-based combined ramjet engine according to claim 1, characterized in that: The core engine (4) comprises a high-pressure compressor (41), a main combustion chamber (42) and a high-pressure turbine (43), wherein the main combustion chamber (42) is located between the high-pressure compressor (41) and the high-pressure turbine (43).

3. The turbine-based combined ramjet engine according to claim 2, characterized in that: The high-pressure compressor (41) and the high-pressure turbine (43) are connected to a high-pressure shaft, and the high-pressure compressor (41) is driven by the high-pressure turbine (43).

4. The turbine-based combined ramjet engine according to claim 1, characterized in that: The supersonic through-flow fan (1) and the low-pressure turbine (5) are connected to a low-pressure shaft, and the supersonic through-flow fan (1) is driven by the low-pressure turbine (5).

5. The turbine-based combined ramjet engine according to claim 2, characterized in that: The ramjet engine has a turbofan mode. In the turbofan mode, the mode selection valve (P) is opened, the outer duct is connected to the supersonic through-flow fan (1), the main combustion chamber (42) is ignited, and the ramjet combustion chamber (7) and the afterburner combustion chamber (6) are not ignited.

6. The turbine-based combined ramjet engine according to claim 2, characterized in that: The ramjet engine has a turbojet mode. In the turbojet mode, the mode selection valve (P) is closed, the outer duct and the supersonic through-flow fan (1) are blocked, the main combustion chamber (42) is ignited, and the ramjet combustion chamber (7) and the afterburner combustion chamber (6) are not ignited.

7. The turbine-based combined ramjet engine according to claim 6, characterized in that: The ramjet engine has a ramjet mode. In the ramjet mode, the mode selection valve (P) is opened, the outer duct is connected to the supersonic through-flow fan (1), the ramjet combustion chamber (7) is ignited, and the main combustion chamber (42) and the afterburner combustion chamber (6) are not ignited.

8. The turbine-based combined ramjet engine according to claim 7, characterized in that: During the process of converting the ramjet engine from the turbojet mode to the ramjet mode, the afterburner chamber (6) is ignited to increase the Mach number of the ramjet engine, and then the mode selection valve (P) is opened, and the ramjet combustion chamber (7) is ignited. After the combustion of the ramjet combustion chamber (7) is stable, the afterburner chamber (6) and the main combustion chamber (42) are extinguished in sequence.

9. The turbine-based combined ramjet engine according to claim 2, characterized in that: The core diffuser (2) is capable of adjusting the capture area, the throat area of ​​the ejector nozzle (9) is capable of adjusting the inlet guide vanes of the high-pressure compressor (41) is capable of adjusting the inlet guide vanes of the low-pressure turbine (5).

10. An aircraft, characterized in that: The aircraft comprises a turbine-based composite ramjet engine as claimed in any one of claims 1 to 9.

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