Gas turbine engine with outlet guide vanes

Abstract

A gas turbine engine is provided having a plurality of outlet guide vanes, each outlet guide vane defining an internal hot fluid passage. Engine defining outlet guide vane cooling capacity greater than 0.01 and less than 13, wherein OGVCC equals: # imgabs 0 # and wherein # imgabs 1 #

Description

Technical Field

[0001] The present disclosure relates to a gas turbine engine having outlet guide vanes. Background Art

[0002] Gas turbine engines, such as turbofan engines, can be used for aircraft propulsion. Turbofan engines typically include a bypass fan section and a turbine that drives the bypass fan. The turbine typically includes a compressor section, a combustion section, and a turbine section in a serial flow arrangement. Both the compressor section and the turbine section are driven by a rotor shaft. Gas turbine engines typically include a thermal management system to manage thermal loads during operation of the gas turbine engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] A full and enabling disclosure of the present disclosure, including the best mode thereof, to one of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0004] Figure 1 is a schematic diagram of an exemplary gas turbine engine according to an exemplary aspect of the present disclosure.

[0005] Figure 2 is a close-up schematic illustration of an exit guide vane according to an exemplary aspect of the present disclosure.

[0006] Figure 3 It is viewed along the radial direction of the gas turbine engine. Figure 2 Schematic diagram of the outlet guide vane.

[0007] Figure 4 is a schematic diagram of an outlet guide vane assembly according to an exemplary embodiment of the present disclosure.

[0008] Figure 5 Yes Figure 4 A schematic diagram of a portion of an outlet guide vane assembly is shown in FIG.

[0009] Figure 6 is a table depicting numerical values ​​showing the relationship between various parameters according to various example embodiments of the present disclosure.

[0010] Figure 7 is a graph depicting parameter ranges for a gas turbine engine according to various example embodiments of the present disclosure.

[0011] Figure 8 is a schematic diagram of an outlet guide vane according to another exemplary embodiment of the present disclosure.

[0012] Fig. 9 is a schematic diagram of an outlet guide vane according to yet another exemplary embodiment of the present disclosure.

[0013] Fig.10 is a schematic diagram of an outlet guide vane assembly according to another exemplary embodiment of the present disclosure.

[0014] Fig.11 is a schematic diagram of an outlet guide vane according to yet another exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0015] Reference will now be made in detail to the present embodiments of the present disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter references to refer to features in the drawings. Like or similar reference numbers in the drawings and description have been used to refer to like or similar parts of the present disclosure.

[0016] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. In addition, unless expressly stated otherwise, all embodiments described herein should be considered exemplary.

[0017] The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0018] The term "at least one" in a context such as "at least one of A, B, and C" means only A, only B, only C, or any combination of A, B, and C.

[0019] The term “turbomachine” refers to a machine that includes one or more compressors, a heat generating section (eg, a combustion section), and one or more turbines that together generate a torque output.

[0020] The term "gas turbine engine" refers to an engine having a turbine as all or part of its power source. Example gas turbine engines include turbofan engines, turboprop engines, turbojets, turboshaft engines, etc., as well as hybrid-electric versions of one or more of these engines.

[0021] The term "combustion section" refers to any heat addition system for a turbomachine. For example, the term combustion section may refer to a section that includes one or more of a deflagration combustion assembly, a rotating detonation combustion assembly, a pulse detonation combustion assembly, or other suitable heat addition assemblies. In certain example embodiments, the combustion section may include an annular combustor, a can combustor, a tubular combustor, a trapped vortex combustor (TVC), or other suitable combustion systems, or a combination thereof.

[0022] The term “takeoff power level” refers to the power level of the gas turbine engine used during a takeoff mode of operation of the gas turbine engine during standard daytime operating conditions.

[0023] The term "standard day operating conditions" refers to ambient conditions of sea level, 59 degrees Fahrenheit, and 60% relative humidity.

[0024] The terms "upstream" and "downstream" refer to relative directions relative to the flow of a fluid in a fluid path. For example, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction toward which the fluid is flowing.

[0025] As used herein, when referring to a plurality of fan blades of a fan, the term "fan tip speed" refers to the linear speed of the outer tip of a fan blade of the plurality of fan blades along a radial direction during operation of the fan. The fan tip speed may be calculated using the following formula: π×2×R fan ×N1 / GB gear ratio , where R fan is the fan radius of the fan, N1 is the rotational speed of the shaft driving the fan (in revolutions per minute), and GB gear ratio is the gear ratio of the shaft across which the fan is driven by the reduction gearbox (if provided).

[0026] As used herein, the term "head loss" refers to the pressure loss of a fluid flowing through a channel due to turbulence caused by, for example, the velocity of the flowing fluid and the roughness of the surface forming the first channel.

[0027] The phrases "from X to Y" and "between X and Y" refer to ranges of values ​​including the endpoints, respectively (ie, to ranges of values ​​including both X and Y).

[0028] Typically, a turbofan engine includes a fan and a turbine, wherein the turbine rotates the fan to generate thrust. The turbine includes a compressor section, a combustion section, a turbine section, and an exhaust section, and defines a working gas flow path therethrough. As turbofan engines are driven to a higher total thrust output, with a higher propulsion efficiency (e.g., less specific fuel consumption for a given amount of thrust output), thermal management within the turbofan engine becomes increasingly important. In particular, operating a turbofan engine to generate a higher total thrust output with higher efficiency may include operating at least some sections of the turbofan engine at a higher temperature, operating components (e.g., gearboxes, bearings, etc.) in a manner that generates more heat, or both.

[0029] The inventors of the present disclosure have attempted to design an engine having a means of managing large amounts of heat without creating new inefficiencies in a turbofan engine, thereby allowing a net gain in propulsive efficiency. In particular, the inventors have recognized that a bypass passage of a turbofan engine typically includes a large amount of airflow passing therethrough at relatively low temperatures. However, the bypass passage provides a large amount of thrust to the turbofan engine (at least a large portion of the thrust in certain engine configurations), such that it is generally undesirable to introduce a heat exchanger within the bypass passage that introduces a significant pressure drop in the airflow through the bypass passage.

[0030] It is possible to introduce a heat exchanger into the outlet guide vanes that already exist in a turbofan engine. However, incorporating a heat exchanger into the outlet guide vanes requires adding additional power to the thermal management system to direct the heat transfer fluid to the outlet guide vanes, and introduces complexity in the design and layout of the turbofan engine. In addition, the outlet guide vanes are typically designed to optimize the aerodynamic efficiency of the airflow through the bypass channel, so that the number, arrangement, and geometry of the outlet guide vanes may not accommodate the desired amount of heat transfer. Although the number, arrangement, and geometry of the outlet guide vanes can be modified to achieve the desired amount of heat transfer, the aerodynamic efficiency cost of such a design may exceed the thermal management benefits. Therefore, the previous idea is that any modification of the aerodynamically optimized design of the outlet guide vanes will result in a decrease in the net propulsive efficiency of the turbofan engine; in addition, incorporating a heat exchanger into the aerodynamically optimized design of the outlet guide vanes will not produce a sufficient amount of heat transfer to justify the additional power usage requirements, complexity, etc.

[0031] However, contrary to previous thinking and expectations, the inventors unexpectedly discovered in the process of designing a turbofan engine for the above-mentioned needs with a heat exchanger integrated into the outlet guide vane that, in at least some designs, the costs associated with being able to provide the desired amount of heat transfer, including a heat exchanger integrated into the outlet guide vane, can be overcome by thermal management benefits. In particular, the inventors discovered in the process of designing several turbofan engines with heat exchangers integrated into the outlet guide vanes, having different thrust ratings and thermal management requirements, including the configurations shown and described herein, that there is a relationship between the outlet guide vane heat transfer surface area parameter, the amount of airflow through the bypass passage available for cooling, and the cooling capacity of such airflow, such that including a heat exchanger integrated into the outlet guide vane according to one or more of the exemplary aspects described herein can result in a net benefit to the overall engine design.

[0032] In order to obtain an improved gas turbine engine capable of providing the desired heat dissipation capacity, the inventors proceeded in the following manner during the design of several different types of heat exchangers integrated into outlet guide vanes (including heat exchangers integrated into the outlet guide vanes described in this article, which will be described in more detail below): design a turbofan engine with a heat exchanger integrated into the outlet guide vane, which has various outlet guide vane heat transfer surface area parameters, various amounts of airflow through the bypass channel that can be used for cooling, and various cooling capacities of such airflow; check the operability and heat dissipation characteristics of the designed turbofan engine; redesign the turbofan engine to change the parameters based on the impact on other aspects of the turbofan engine; recheck the operability and heat dissipation characteristics of the redesigned turbofan engine, etc.

[0033] Referring now to the drawings, wherein like numerals refer to like elements throughout, Figure 1 is a schematic cross-sectional view of a gas turbine engine according to an exemplary embodiment of the present disclosure. More specifically, Figure 1 In an embodiment of the present invention, the gas turbine engine is a high bypass turbofan jet engine, sometimes also referred to as a "turbofan engine". Figure 1 As shown, the gas turbine engine 10 defines an axial direction A (extending parallel to a longitudinal centerline 12 provided for reference), a radial direction R, and a circumferential direction C extending about the longitudinal centerline 12. Generally, the gas turbine engine 10 includes a fan section 14 and a turbine 16 disposed downstream of the fan section 14.

[0034] The depicted exemplary turbine 16 generally includes a substantially tubular casing 18 defining an annular inlet 20. The casing 18 encloses, in serial flow relationship: a compressor section including a supercharger or low pressure (LP) compressor 22 and a high pressure (HP) compressor 24; a combustion section 26; a turbine section including a high pressure (HP) turbine 28 and a low pressure (LP) turbine 30; and an injection exhaust nozzle section 32. A high pressure (HP) shaft 34 (which may additionally or alternatively be a spool) drivingly connects the HP turbine 28 to the HP compressor 24. A low pressure (LP) shaft 36 (which may additionally or alternatively be a spool) drivingly connects the LP turbine 30 to the LP compressor 22. The compressor section, combustion section 26, turbine section, and injection exhaust nozzle section 32 together define a working gas flow path 37.

[0035] For the described embodiment, the fan section 14 includes a fan 38 having a plurality of fan blades 40 coupled to a disk 42 in a spaced-apart manner. As depicted, the fan blades 40 extend outwardly from the disk 42 generally in a radial direction R. Each fan blade 40 can rotate about a pitch axis P relative to the disk 42 by virtue of the fan blades 40 being operably coupled to an appropriate pitch mechanism 44, the pitch mechanism 44 being configured to collectively change the pitch of the fan blades 40, e.g., in unison. The gas turbine engine 10 also includes a power gearbox 46, and the fan blades 40, disk 42, and pitch mechanism 44 can rotate together about the longitudinal centerline 12 across the power gearbox 46 via the LP shaft 36. The power gearbox 46 includes a plurality of gears for adjusting the rotational speed of the fan 38 relative to the rotational speed of the LP shaft 36 so that the fan 38 can rotate at a more efficient fan speed. In this manner, it should be understood that the power gearbox 46 defines a rotational speed equal to the input rotational speed (i.e., Figure 1 The rotational speed of the LP shaft 36 in the embodiment of ) divided by the output rotational speed (ie, Figure 1 The gear ratio of the fan 38 in the embodiment of the invention is the rotational speed of the fan 38.

[0036] Still reference Figure 1 In the exemplary embodiment of the fan section 14, the disk 42 is covered by a rotatable front hub 48 (sometimes also referred to as a "spinner") of the fan section 14. The front hub 48 is aerodynamically shaped to facilitate airflow through the plurality of fan blades 40.

[0037] In addition, the exemplary fan section 14 includes an annular fan case or outer nacelle 50 that circumferentially surrounds at least a portion of the fan 38 and / or the turbine 16. It should be understood that in the depicted embodiment, the nacelle 50 is supported relative to the turbine 16 by a plurality of circumferentially spaced outlet guide vanes 52. In addition, the nacelle 50, including a downstream section 54 of the nacelle 50, extends over an outer portion of the turbine 16 to define a bypass passage 56 therebetween. The plurality of outlet guide vanes 52 are located within (i.e., extend through) the bypass passage 56 at a location downstream of the fan 38.

[0038] During operation of the gas turbine engine 10, a quantity of air 58 enters the gas turbine engine 10 through the nacelle 50 and the associated inlet 60 of the fan section 14. As the quantity of air 58 passes through the fan blades 40, a first portion of air 62 is directed or directed into the bypass passage 56, and a second portion of air 64, as indicated by arrow 64, is directed or directed into the working gas flow path 37, or more specifically, into the LP compressor 22. The ratio between the first portion of air 62 and the second portion of air 64 is generally referred to as a bypass ratio. The pressure of the second portion of air 64 is then increased as the second portion of air 64 is directed through the HP compressor 24 and into the combustion section 26, where the second portion of air 64 is mixed with fuel and combusted to provide combustion gases 66.

[0039] The combustion gases 66 are directed through the HP turbine 28, wherein a portion of the thermal and / or kinetic energy from the combustion gases 66 is extracted via sequential stages of HP turbine stator blades 68 coupled to the casing 18 and HP turbine rotor blades 70 coupled to the HP shaft 34, thereby rotating the HP shaft 34 to support operation of the HP compressor 24. The combustion gases 66 are then directed through the LP turbine 30, wherein a second portion of the thermal and kinetic energy is extracted from the combustion gases 66 via sequential stages of LP turbine stator blades 72 coupled to the casing 18 and LP turbine rotor blades 74 coupled to the LP shaft 36, thereby rotating the LP shaft 36 to support operation of the LP compressor 22 and / or rotation of the fan 38.

[0040] The combustion gases 66 are then directed through the jet exhaust nozzle section 32 of the turbine 16 to provide propulsive thrust. At the same time, the pressure of the first portion of air 62 is significantly increased, also providing propulsive thrust, as it is directed through the bypass passage 56 before being discharged from the fan nozzle exhaust section 76 of the gas turbine engine 10. The HP turbine 28, the LP turbine 30, and the jet exhaust nozzle section 32 at least partially define a hot gas path 78 for directing the combustion gases 66 through the turbine 16.

[0041] As will be appreciated, the gas turbine engine 10 defines a total engine thrust Fn during operating conditions of the gas turbine engine 10. Total Total engine thrust Fn Total It can usually be equal to the fan flow thrust Fn during operating conditions Fan (i.e., the amount of thrust generated by the fan 38 through the bypass passage 56) and the turbine thrust Fn TMThe operating condition may be a high power operating condition, such as a takeoff operating condition, a climb operating condition, a maximum power cruise operating condition, etc. For example, the operating condition may be a condition where the engine provides thrust at a takeoff power level.

[0042] In addition, the gas turbine engine 10 can be configured to generate a total sea level static thrust output corrected to standard day conditions, substantially equal to the thrust at the takeoff power level. It should be understood that "sea level static thrust corrected to standard day conditions" refers to the amount of thrust that the engine is capable of producing when stationary relative to the earth and the surrounding air during standard day operating conditions.

[0043] The gas turbine engine 10 may define a total sea level static thrust output greater than or equal to 11,000 pounds. For example, it will be appreciated that the gas turbine engine 10 may be configured to generate at least 25,000 pounds and less than 115,000 pounds (such as between 25,000 pounds and 80,000 pounds, such as between 35,000 pounds and 65,000 pounds) of thrust during takeoff operating power, corrected to standard day sea level conditions.

[0044] However, it should be understood that Figure 1 The exemplary gas turbine engine 10 depicted in FIG. 1 is merely an example, and in other exemplary embodiments, the gas turbine engine 10 may have any other suitable configuration. For example, although the depicted gas turbine engine 10 is configured as a ducted gas turbine engine (i.e., including an outer nacelle 50), in other embodiments, the gas turbine engine 10 may be a non-ducted gas turbine engine (such that the fan 38 is a non-ducted fan and the outlet guide vanes 52 are cantilevered from the casing 18). Additionally or alternatively, although the depicted gas turbine engine 10 is configured as a geared gas turbine engine (i.e., including a power gearbox 46) and a variable pitch gas turbine engine (i.e., including a fan 38 configured as a variable pitch fan), in other embodiments, the gas turbine engine 10 may additionally or alternatively be configured as a direct drive gas turbine engine (such that the LP shaft 36 rotates at the same speed as the fan 38), a fixed pitch gas turbine engine (such that the fan 38 includes fan blades 40 that are non-rotatable about the pitch axis P), or both. It should also be understood that in other exemplary embodiments, aspects of the present disclosure may be incorporated into any other suitable gas turbine engine.

[0045] Still reference Figure 1It should be understood that the gas turbine engine also includes one or more engine systems 80. The one or more engine systems 80 may include a lubricating oil system (providing lubricating oil to various bearings, power gearbox 46, etc.), a power electronics system, an integrated drive generator, etc., including combinations thereof. The one or more engine systems 80 may generate relatively large amounts of heat during at least certain operations.

[0046] therefore, Figure 1 The exemplary gas turbine engine 10 also includes a thermal management system 82 in thermal communication with the one or more engine systems 80 for reducing the temperature of the one or more engine systems 80. The thermal management system 82 generally includes a circulation assembly 84 (which generally may include a pump) and a plurality of heat exchangers 86 integrated with the outlet guide vanes 52. In this manner, the thermal management system 82 is integrated with the turbine 16 and the outlet guide vanes 52.

[0047] Reference now Figure 2 , provides Figure 1 The gas turbine engine 10, and in particular Figure 1 A close-up schematic diagram of a plurality of outlet guide vanes 52 of a gas turbine engine 10. Note that for clarity, Figure 2 Aspects of the thermal management system 82 are omitted from the view of FIG.

[0048] As described above, a plurality of outlet guide vanes 52 are located within bypass passage 56 and extend through bypass passage 56 at a location downstream of fan 38. In particular, each outlet guide vane 52 extends generally along radial direction R between base 88 and tip 90 and defines leading edge 92 and trailing edge 94. Base 88 is coupled to turbine 16 and meets casing 18. Tip 90 is coupled to outer nacelle 50 and meets inner surface 51 of outer nacelle 50.

[0049] In addition, each exit guide vane 52 defines a base radius R OGV_Base and tip radius R OGV_Tip . Base radius R OGV_Base is the distance along the radial direction R from the longitudinal centerline 12 to the location where the leading edge 92 of the outlet guide vane 52 meets the casing 18, and the tip radius R OGV_Tip The base radius R is the distance along the radial direction R from the longitudinal centerline 12 to the location where the leading edge 92 of the outlet guide vane 52 meets the inner surface 51 of the nacelle 50. OGV_Base With tip radius R OGV_Tip The ratio of the exit guide vane radius ratio R OGV_ratio .

[0050] In addition, we now briefly refer to Figure 3, provides a view of the outlet guide vane 52 along the radial direction R, as shown Figure 2 As shown by line 3-3 in FIG. 3 , it should be understood that each of the outlet guide vanes 52 defines a pitch angle, referred to herein as OGV angle θ, with respect to a reference line 98 defined by the gas turbine engine 10. OGV ; Reference line 98 is parallel to the axial direction A and the longitudinal centerline 12. In particular, the exit guide vane 52 defines a reference line 96 extending from the leading edge 92 to the trailing edge 94 at the 50% span position, and the OGV angle θ OGV is the angle between reference line 96 and reference line 98 .

[0051] Furthermore, it should be appreciated that the fan blades 40 of the fan 38 each include a tip 41 at an outermost position along the radial direction R, and that the fan 38 defines a fan radius R fan , fan radius R fan is equal to the distance from the longitudinal centerline 12 to the tip 41 of the fan blade 40 along the radial direction R. The fan 38 further defines a fan diameter D fan , fan diameter D fan Equal to the fan radius R fan twice as much.

[0052] As discussed above, the present disclosure generally provides a gas turbine engine having a thermal management system integrated with a turbine and exit guide vanes of the gas turbine engine.

[0053] Reference now Figure 4 , Figure 4 A schematic diagram of an exemplary outlet guide vane assembly 100 is provided according to various embodiments of the present disclosure. The exemplary outlet guide vane assembly 100 may be incorporated into a Figure 1 The exemplary gas turbine engine 10 is constructed in a similar manner to other gas turbine engines.

[0054] like Figure 4 As shown, the outlet guide vane assembly 100 includes a plurality of outlet guide vanes 102, and in particular, the plurality of outlet guide vanes 102 includes a plurality of (N OGV ) outlet guide vanes 102. Figure 4 In the embodiment, N OGV is 12. However, it should be understood that Figure 4 The number N of the exit guide vanes 102 shown in FIG. OGV It is not limiting, and the exit guide vane assembly 100 may include more exit guide vanes 102 or fewer exit guide vanes 102 than shown, as discussed in more detail below.

[0055] like Figure 4As shown, each outlet guide vane 102 includes a heat exchanger integrated therein. In this manner, the depicted outlet guide vane assembly 100 may be configured as part of a thermal management system 200 for a gas turbine engine that includes the outlet guide vane assembly 100 .

[0056] More specifically, each outlet guide vane 102 extends through the bypass passage 56 along the radial direction R (see, for example, Figure 1 and Figure 2 The outlet guide vanes 102 are provided with a bypass passage 56 of the inner thermal fluid passage 104 and define an inner thermal fluid passage 104. The inner thermal fluid passage 104 is thermally connected to an outer surface 105 of the corresponding outlet guide vane 102, thereby allowing the outlet guide vane 102 to serve as a heat exchanger between a heat transfer fluid flowing through the inner thermal fluid passage 104 and an airflow passing through the bypass passage 56.

[0057] In the exemplary embodiment depicted, outlet guide vane assembly 100 also includes a first annular manifold and a second annular manifold. Figure 4 In the embodiment of the present invention, the first annular manifold and the second annular manifold are an inner annular manifold 106 and an outer annular manifold 108. Each outlet guide vane 102 extends radially between the inner annular manifold 106 and the outer annular manifold 108. The inner annular manifold 106 may be positioned inside the outer casing of the turbine (e.g., Figure 1 The outer ring manifold 108 may be positioned on the inner surface of the outer nacelle (eg, Figure 1 The inner surface 51 of the outer nacelle 50 is located outside the radial direction R).

[0058] The inner ring manifold 106 includes openings 110 for allowing fluid to flow into or out of the inner ring manifold 106. The outer ring manifold 108 includes openings 112 for allowing fluid to flow into or out of the outer ring manifold 108. Each internal thermal fluid path is in fluid communication with the inner ring manifold 106 and the outer ring manifold 108. The internal thermal fluid paths may be formed by one or more channels, grooves, chambers, etc. defined in the respective outlet guide vanes 102 that allow cooling fluid to flow between the inner ring manifold 106 and the outer ring manifold 108.

[0059] Also briefly refer to Figure 5 , Figure 5 Provides such as Figure 4 Schematic diagram of a portion of an outlet guide vane assembly 100 is shown in FIG. Figure 4 and Figure 5 As shown in FIG. 1 , each outlet guide vane 102 includes a plurality of outlet guide vanes 102 with respect to the radial direction R and the longitudinal centerline 12 (ie, the longitudinal centerline 12 of the gas turbine engine; see FIG. 1 ). Figure 1The outlet guide vanes 102 further include a radially outer portion 114 relative to the longitudinal centerline 12 of the outer ring manifold 108, the radially outer portion 114 being rigidly connected to an inner surface 116 of the outer ring manifold 108. Each outlet guide vane 102 also includes a radially inner portion 118 relative to the radial direction R and the longitudinal centerline 12, the radially inner portion 118 being rigidly connected to an outer surface 120 of the inner ring manifold 106.

[0060] Specific return reference Figure 4 The thermal management system 200 is also provided for cooling one or more engine systems 80, such as a gas turbine engine including the thermal management system 200 (see also Figure 1 engine system 80).

[0061] The thermal management system 200 also includes a circulation assembly 202 and a plurality of heat exchangers integrated with the outlet guide vanes 102. In the illustrated embodiment, the circulation assembly 202 includes a pump 204. Figure 4 In the embodiment of the present invention, a “heat exchanger integrated with the outlet guide vane” may refer to a structure of the outlet guide vane 102 that defines an internal hot fluid passage 104 and thermally connects the internal hot fluid passage 104 to a corresponding outer surface 105 of the outlet guide vane 102 .

[0062] In the depicted embodiment, the circulation assembly 202 also includes a heat exchanger 206 that thermally connects the heat transfer fluid of the thermal management system 200 to the one or more engine systems 80. In this manner, it should be appreciated that the heat transfer fluid of the thermal management system 200 is separated from the fluid of the one or more engine systems 80.

[0063] However, it should be understood that in other exemplary embodiments, the heat transfer fluid of the thermal management system 200 may be the same fluid as the fluid that circulates through the one or more engine systems 80. For example, the one or more engine systems 80 may be a lubricating oil system, and the one or more engine systems 80 may provide lubricating oil directly to the circulation component 202 so that the circulation component 202 circulates through the thermal management system 200, thereby cooling such lubricating oil (in which case such lubricating oil would be considered the "heat transfer fluid" of the thermal management system 200).

[0064] Still reference Figure 4 The thermal management system 200 also includes a network of pipes 208 that fluidly connect the circulation assembly 202 with the inner ring manifold 106 and the outer ring manifold 108. In particular, the pipes 208 include one or more inlet pipes 208A that provide the heat transfer fluid to the outer ring manifold 108 and one or more outlet pipes 208B that provide the heat transfer fluid from the inner ring manifold 106.

[0065] In this way, it should be understood that Figure 4The thermal management system 200 may utilize the relatively cool airflow through the bypass passage 56 to cool one or more engine systems 80 without requiring a dedicated heat exchanger positioned in the bypass passage 56 , potentially resulting in a reduced pressure drop within the bypass passage 56 while still achieving the desired heat transfer.

[0066] As previously mentioned, the inventors unexpectedly discovered during the process of designing a turbofan engine with a heat exchanger integrated into an outlet guide vane (OGV) - that is, designing a turbofan engine with a heat exchanger integrated into the OGV that is capable of providing a desired amount of heat dissipation, and evaluating overall engine and heat transfer performance, that there is a significant relationship between the outlet guide vane heat transfer surface area parameter, the amount of airflow available for cooling through the bypass passage, and the cooling capacity of such airflow. This relationship can be considered an indicator of the ability of a turbofan engine with a heat exchanger integrated into the OGV to remove a sufficient amount of heat from the heat transfer fluid to justify any additional power usage requirements and complexity, to overcome any aerodynamic degradation caused by incorporating the heat exchanger, or both. In particular, the inventors discovered that the combination of these parameters can indicate that a particular turbofan engine design will be able to remove a sufficient amount of heat from the heat transfer fluid to justify any additional power usage requirements and complexity, to overcome any aerodynamic degradation caused by incorporating the heat exchanger, or both.

[0067] The relationship is applicable to a gas turbine engine having a fan and a turbine and defining a bypass passage on the turbine, wherein the OGV extends into and / or through the bypass passage. The relationship converts the outlet guide vane heat transfer surface area parameter (HTSA) to OGV ; which can generally relate the amount of surface area within the internal thermal fluid passages of the OGVs to the external surface areas of the OGVs, the total number of OGVs, and the angles and spacing of the OGVs) to the amount of airflow available for cooling through the bypass passage (as indicated by the magnitude of the bypass ratio and certain operating conditions of the turbofan engine) and the cooling capacity of such airflow, as described in more detail below.

[0068] In particular, the inventors have discovered that including an array of OGVs can result in an increase in the heat transfer capacity of the OGVs, wherein the OGVs have an increased internal surface area relative to the external surface area (i.e., the total surface area of ​​the internal thermal fluid passages that receive the heat transfer fluid to be cooled). Similarly, including a greater number of OGVs and spacing the OGVs closer together can also result in an increase in the heat transfer capacity of the OGVs due, at least in part, to an increase in turbulence of the airflow flowing through the OGVs through the bypass passages. However, as these aspects of the turbofan are increased, the pressure drop of the airflow through the array of OGVs through the bypass passages is also increased, which can reduce the amount of thrust generated by the turbofan engine (thereby reducing the efficiency of the turbofan engine).

[0069] It is worth noting that, depending on the configuration of the internal thermal fluid pathways, increasing the internal surface area may also correspondingly increase the head loss of the heat transfer fluid passing through the internal thermal fluid pathways. While this is generally associated with increased heat transfer, it also requires more energy in the form of a fluid pump to drive the heat transfer fluid through the thermal management system.

[0070] Additionally, increasing the fan diameter of the fan and the bypass ratio of the turbofan engine can result in a greater amount of airflow available to cool the heat transfer fluid flowing through the OGV during operation. However, increasing these aspects may require a larger and more powerful turbine to effectively drive such a fan.

[0071] Thus, the relationships discovered below can be used to identify a turbofan engine with a heat exchanger integrated into an OGV that: is capable of achieving sufficient heat dissipation to justify any additional power usage requirements and complexity, to outweigh any aerodynamic degradation resulting from incorporating the heat exchanger, or both; and is suitable for a particular mission requirement that takes into account efficiency, weight, thermal capacity requirements, complexity, reliability, and other factors that influence the optimal selection of a turbofan engine with a heat exchanger integrated into an OGV.

[0072] In addition to producing an improved gas turbine engine with a heat exchanger integrated into the OGV, as explained in detail above, utilizing this relationship, the inventors have discovered that the number of suitable or feasible turbofan engine designs that can meet the above-mentioned design requirements can be greatly reduced, thereby facilitating a more rapid down-selection of designs to be considered when developing a turbofan engine (with a heat exchanger integrated into the OGV). Such a benefit provides more insight into the requirements of a given turbofan engine before the specific technical, integration, and system requirements are fully developed. Such a benefit avoids late-stage redesigns.

[0073] A desirable relationship discovered by the inventors to provide an improved turbofan engine is the outlet guide vane cooling capacity (OGVCC), expressed as:

[0074] in

[0075] And among them

[0076] BPR is the bypass ratio defined by the gas turbine engine;

[0077] C air is the volumetric heat capacity of the gas flow through the bypass passage of the gas turbine engine at a location immediately upstream of the plurality of OGVs during operating conditions of the gas turbine engine, expressed in joules per cubic meter times degrees Celsius (J / m3×C);

[0078] T air is the temperature of the gas flow through the bypass passage of the gas turbine engine at a location immediately upstream of the plurality of OGVs during operating conditions of the gas turbine engine, in degrees Celsius;

[0079] T inlet is the temperature of the heat transfer fluid provided to the inlet of the internal hot fluid passage of the OGV during operating conditions of the gas turbine engine, in degrees Celsius;

[0080] v flight is the flight speed of the gas turbine engine during the operating conditions of the gas turbine engine, in meters per second;

[0081] D fan is the fan diameter of the gas turbine engine fan in meters;

[0082] is the square of the fan diameter, in square meters;

[0083] v tip speed is the tip speed of the fan during the operating conditions of the gas turbine engine, in meters per second;

[0084] Fn Total is the total thrust output of the gas turbine engine during the operating conditions of the gas turbine engine;

[0085] ΔH is the head loss of the heat transfer fluid through the internal hot fluid passages of the OGV during the operating conditions of the gas turbine engine, in meters;

[0086] N vane is the number of OGVs in the plurality of OGVs;

[0087] R OGV_ratio It is equal to the base radius of the OGV divided by the tip radius of the OGV;

[0088] YesR OGV_ratio The square of

[0089] θ OGV is the OGV angle, or more precisely, the OGV pitch angle, between a reference line extending from the leading edge of the OGV to the trailing edge of the OGV and a reference line parallel to the axial direction of the turbofan engine at the 50% span position of the OGV, in degrees;

[0090] f OGV is the ratio of the total surface area of ​​the internal hot fluid passages of the outlet guide vanes of the plurality of OGVs to the total surface area of ​​the external surfaces of the outlet guide vanes exposed to the bypass passage.

[0091] For the above OGVCC, the parameters have values ​​selected from the following ranges in Table 1 in appropriate combinations to meet the desired range of OGVCC values ​​according to the present disclosure:

[0092]

[0093] Reference now Figure 6 and Figure 7 Various gas turbine engines having thermal management systems according to the present disclosure are provided. Figure 6 Provides includes and falls into Figure 7 A table of corresponding values ​​for several gas turbine engines having thermal management systems within the range depicted. Figure 7 A plot 300 of OGVCC on a Y-axis 302 and bypass ratio on an X-axis 304 is provided.

[0094] like Figure 7 As shown, plot 300 depicts a first range 306 where the OGVCC value is greater than or equal to 0.01 and less than or equal to 12.9 and the bypass ratio is greater than or equal to 3 and less than or equal to 30.

[0095] Figure 7 Additionally depicted is a second range 308 wherein the OGVCC value is greater than or equal to 3.23 and less than or equal to 13 and the bypass ratio is greater than or equal to 3 and less than or equal to 30. The second range 308 may generally correspond to an engine having an OGV with a higher OGV surface area function facilitated, for example, via multiple hot fluid passages through the OGV, complex geometry of the fluid passages through the OGV, and the like.

[0096] Figure 7 Additionally depicted is a third range 310 where the OGVCC value is greater than or equal to 0.01 and less than or equal to 6.21 and the bypass ratio is greater than or equal to 13 and less than or equal to 30. The third range 310 may generally correspond to an engine having an OGV with a smaller OGV surface area function, for example due to a more simplified hot fluid path through the OGV, but with a higher BPR to provide a desired amount of heat transfer.

[0097] It should be understood that while the above discussion generally relates to a gas turbine engine having a thermal management system having a heat exchanger integrated into exit guide vanes 400 , wherein exit guide vanes 400 each define a unidirectional internal hot fluid passage 410 , in other exemplary embodiments, other configurations may be provided.

[0098] For example, refer to Figure 8, provides a cross-sectional view of an outlet guide vane 400 having a heat exchanger integrated therein according to another exemplary aspect of the present disclosure. Figure 8 The exemplary outlet guide vane 400 may be incorporated into one or more of the exemplary embodiments described herein (such as those described above with reference to, for example, Figure 4 In the exemplary system described herein.

[0099] Therefore, it should be understood that Figure 8 The exemplary outlet guide vane 400 generally defines a leading edge 402, a trailing edge 404, a base 406, and a tip 408. The exemplary outlet guide vane 400 further defines an internal thermal fluid passage 410 that generally extends from the base 406 to the tip 408. However, for the depicted embodiment, the internal thermal fluid passage 410 is a first internal thermal fluid passage 410 of a plurality of internal thermal fluid passages 410 defined by the outlet guide vane 400, wherein each of the plurality of internal thermal fluid passages 410 generally extends from the base 406 to the tip 408. Each of the plurality of internal thermal fluid passages 410 may be in thermal communication with an outer surface 412 of the outlet guide vane 400 to facilitate heat transfer from a heat transfer fluid 414 flowing through each of the plurality of internal thermal fluid passages 410 to an airflow through a bypass passage extending through the outlet guide vane 400.

[0100] In addition, now refer to Fig. 9 , provides a cross-sectional view of an outlet guide vane 400 ′ having a heat exchanger integrated therein according to another exemplary embodiment of the present disclosure. Fig. 9 The exemplary exit guide vane 400' may be provided with Figure 8 The exemplary outlet guide vane 400 is constructed in a similar manner, and the same or similar numbers may refer to the same or similar parts. Fig. 9 The exemplary outlet guide vane 400' may be similarly integrated into one or more of the exemplary embodiments described herein (such as those described above with reference to, for example, Figure 4 In the exemplary embodiment described herein.

[0101] For example, Fig. 9 The exemplary outlet guide vane 400' generally defines an internal hot fluid passage 410'. The outlet guide vane 400' also includes a plurality of thermal members 416 extending through the internal hot fluid passage 410' to generate turbulence in the flow of a heat transfer fluid 414' flowing through the internal hot fluid passage 410'. In the depicted embodiment, the thermal members 416 are configured as pins. However, in other embodiments, the thermal members 416 may be configured in any other suitable manner having any other suitable geometry.

[0102] Reference now Fig.10, an outlet guide vane assembly 500 and a thermal management system 502 according to another exemplary embodiment of the present disclosure are provided. Fig.10 The exemplary embodiments can be used in the same manner as described above. Figure 4 The exemplary embodiment of the present invention is constructed in a similar manner and accordingly may be incorporated into a gas turbine engine (such as Figure 1 and Figure 2 In a gas turbine engine 10).

[0103] For example, Fig.10 The exemplary embodiment of the invention generally includes a plurality of outlet guide vanes 504, wherein each outlet guide vane 504 defines an internal thermal fluid passage 506. The thermal management system 502 also includes a first annular manifold 508 configured to provide a flow of heat transfer fluid 414 to the internal thermal fluid passage 506 of the outlet guide vanes 504 and a second annular manifold 510 configured to receive a flow of heat transfer fluid 414 from the internal thermal fluid passage 506 of the outlet guide vanes 504.

[0104] However, for Fig.10 In the embodiment of the present invention, the first annular manifold 508 and the second annular manifold 510 are each located inside the bypass passage 56 along the radial direction R of the gas turbine engine. More specifically, for the depicted embodiment, the second annular manifold 510 is nested within the first annular manifold 508 .

[0105] Now also refer to Fig.11 , provides Fig.10 514. Referring to the schematic cross-sectional view of an outlet guide vane 504 in a plurality of outlet guide vanes 504, it should be understood that the internal thermal fluid passage 506 defines an inlet 512 and an outlet 514, wherein each of the inlet 512 and the outlet 514 is located at a base 516 of the outlet guide vane 504. In this manner, the internal thermal fluid passage 506 extends from the base 516 to a position proximate to the tip 518 of the outlet guide vane 504 (i.e., a position closer to the tip 518 and the base 516), and returns to the base 516.

[0106] Despite Fig.11 A single ring is depicted in the embodiment of FIG. 5 , but the internal thermal fluid passage 506 may define any other suitable shape, such as a serpentine shape, a multi-ring shape, etc.

[0107] As will be understood, Fig.10 and Fig.11 Exemplary embodiments of the present invention may provide a more centralized distribution system for the thermal management system 502 .

[0108] Further aspects are provided by the subject matter of the following clauses:

[0109] A gas turbine engine with a defined radial direction, the gas turbine engine comprising: a fan section, the fan section having a defined fan diameter D fan a fan; a turbine rotatably coupled to the fan of the fan section and defining an inlet, the gas turbine engine defining a bypass passage and a bypass ratio (BPR), the bypass passage being downstream of the fan and outside the turbine along the radial direction, the BPR being equal to the ratio of the airflow through the bypass passage to the airflow through the inlet of the turbine during operating conditions of the gas turbine engine; a plurality of outlet guide vanes extending from the turbine at a position downstream of the fan, the plurality of outlet guide vanes comprising a plurality (N vane ) outlet guide vanes, each outlet guide vane is limited to: radius ratio R OGV_ratio , R OGV_ratio = equal to the tip radius of the outlet guide vane divided by the base radius of the outlet guide vane; internal hot fluid passage; outlet guide vane passage size factor f OGV , f OGV a thermal management system integrated with the turbine and the plurality of outlet guide vanes, the thermal management system being in fluid communication with the internal thermal fluid passage of each of the plurality of outlet guide vanes for providing a heat transfer fluid to the internal thermal fluid passage of each of the plurality of outlet guide vanes; wherein during operation of the gas turbine engine under the operating conditions: the airflow through the bypass passage immediately upstream of the plurality of outlet guide vanes defines a temperature T in degrees Celsius air and the volumetric heat capacity C in joules per cubic meter-degree Celsius air The thermal management system defines the heat transfer fluid temperature T at the inlet of the internal thermal fluid passage inlet , and a head loss ΔH of the heat transfer fluid passing through each of the internal thermal fluid passages; the gas turbine engine limits a flight speed v flight and total engine thrust Fn Total , and the fan defines a fan tip speed v tip speed ; and the outlet guide vane cooling capacity (OGVCC) is greater than 0.01 and less than 13, where OGVCC is equal to:

[0110]

[0111] in

[0112]

[0113] A gas turbine engine as in any preceding clause, wherein OGVCC is greater than or equal to 0.01 and less than or equal to 6.21.

[0114] A gas turbine engine as described in any preceding clause, wherein the BPR is greater than or equal to 3 and less than or equal to 30.

[0115] A gas turbine engine as in any preceding clause, wherein OGVCC is greater than or equal to 3.23 and less than or equal to 13, and wherein BPR is greater than or equal to 13 and less than or equal to 30.

[0116] A gas turbine engine according to any preceding clause, wherein f OGV Greater than or equal to 0.05 and less than or equal to 20.

[0117] A gas turbine engine according to any preceding clause, wherein f OGV Greater than or equal to 0.05 and less than or equal to 5.

[0118] A gas turbine engine according to any preceding clause, wherein D fan greater than or equal to 0.5 m and less than or equal to 3.5 m, and where N vane Greater than or equal to 8 and less than or equal to 120.

[0119] A gas turbine engine as claimed in any preceding clause, wherein ΔH is less than or equal to 250 metres.

[0120] A gas turbine engine according to any preceding clause, wherein T inlet is greater than or equal to 50 degrees Celsius and less than or equal to 250 degrees Celsius, and wherein T air Greater than or equal to -56.6 degrees Celsius and less than or equal to 60 degrees Celsius.

[0121] A gas turbine engine as claimed in any preceding clause, wherein the heat transfer fluid is lubricating oil for the gas turbine engine.

[0122] A gas turbine engine according to any preceding clause, wherein θ OGV Greater than or equal to zero degrees and less than or equal to 85 degrees.

[0123] The gas turbine engine of any preceding clause, further comprising an outer nacelle at least partially surrounding the fan and the turbine, wherein the exit guide vanes extend from the turbine to the outer nacelle.

[0124] A method of operating a gas turbine engine, the method comprising: operating the gas turbine engine under an operating condition, wherein the gas turbine engine includes a plurality of outlet guide vanes extending from the turbine at a location downstream of a fan, the plurality of outlet guide vanes comprising a plurality (N vane ) outlet guide vanes, each outlet guide vane is limited to: radius ratio R OGV_ratio , R OGV_ratio = equal to the tip radius of the outlet guide vane divided by the base radius of the outlet guide vane; internal hot fluid passage; and outlet guide vane passage size factor f OGV , f OGV =equal to the ratio of the total surface area of ​​the internal hot fluid passage to the total surface area of ​​the outer surface of the outlet guide vane exposed to the bypass passage; wherein operating the gas turbine engine under the operating conditions comprises: operating the gas turbine engine to limit the flight speed v flight , total engine thrust Fn Total and bypass ratio BPR; and operating the fan to define the fan diameter D fan and fan tip speed v tip speed wherein when operating the gas turbine engine under the operating conditions, the airflow through the bypass passage immediately upstream of the plurality of outlet guide vanes defines a temperature T in degrees Celsius air and the volumetric heat capacity C in joules per cubic meter-degrees Celsius (ie, joules per cubic meter × degrees Celsius C) air ; wherein the heat transfer fluid of the thermal management system of the gas turbine engine defines a heat transfer fluid temperature T at the inlet of each internal heat fluid passage of each outlet guide vane of the plurality of outlet guide vanes; inlet and a head loss ΔH through the internal hot fluid passage; and wherein operating the gas turbine engine under the operating conditions further comprises defining an outlet guide vane cooling capacity (OGVCC) greater than 0.01 and less than 13, wherein OGVCC is equal to:

[0125]

[0126] in

[0127]

[0128] A method as in any preceding clause, wherein OGVCC is greater than or equal to 0.01 and less than or equal to 6.21.

[0129] A method as in any preceding clause, wherein the BPR is greater than or equal to 3 and less than or equal to 30.

[0130] A method as in any preceding clause, wherein the BPR is greater than or equal to 13 and less than or equal to 30.

[0131] A method according to any preceding clause, wherein f OGV Greater than or equal to 0.05 and less than or equal to 20.

[0132] A method as claimed in any preceding clause, wherein the heat transfer fluid is lubricating oil for the gas turbine engine.

[0133] A method according to any preceding clause, wherein D fan greater than or equal to 0.5 m and less than or equal to 3.5 m, and where N vane Greater than or equal to 8 and less than or equal to 120.

[0134] A method as in any preceding clause, wherein the gas turbine engine further comprises an outer nacelle at least partially surrounding the fan and the turbine, wherein the exit guide vanes extend from the turbine to the outer nacelle.

[0135] This written description uses examples to disclose the present disclosure, including the best mode, and also enables any person skilled in the art to practice the present disclosure, including making and using any device or system and performing any combined methods. The patent scope of the present disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. If these other examples include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims, these other examples are intended to fall within the scope of the claims.

Claims

1. A gas turbine engine with a defined radial direction, characterized in that: The gas turbine engine comprises: A fan section having a defined fan diameter D fan Fan; a turbine rotatably coupled to the fan of the fan section and defining an inlet, the gas turbine engine defining a bypass passage and a bypass ratio (BPR), the bypass passage being downstream of the fan and outboard of the turbine in the radial direction, the BPR being equal to a ratio of airflow through the bypass passage to airflow through the inlet of the turbine during operating conditions of the gas turbine engine; a plurality of outlet guide vanes extending from the turbine at a location downstream of the fan, the plurality of outlet guide vanes comprising a plurality (N vane ) outlet guide vanes, each outlet guide vane is limited to: radius ratio R OGV_ratio , R OGV_ratio = equal to the tip radius of the outlet guide vane divided by the base radius of the outlet guide vane; internal hot fluid passage; outlet guide vane passage size factor f OGV , f OGV is equal to the ratio of the total surface area of ​​the internal hot fluid passage to the total surface area of ​​the exterior surface of the outlet guide vane exposed to the bypass passage; a thermal management system integrated with the turbine and the plurality of exit guide vanes, the thermal management system being in fluid communication with the internal thermal fluid passage of each of the plurality of exit guide vanes for providing a heat transfer fluid to the internal thermal fluid passage of each of the plurality of exit guide vanes; wherein during operation of the gas turbine engine under the operating conditions: The airflow through the bypass passage immediately upstream of the plurality of exit guide vanes defines a temperature T in degrees Celsius air and the volumetric heat capacity C in joules per cubic meter-degree Celsius air ; The thermal management system defines a heat transfer fluid temperature T at the inlet of the internal thermal fluid passage inlet , and a head loss ΔH of the heat transfer fluid passing through each of the internal thermal fluid passages; The gas turbine engine limits the flight speed v flight and total engine thrust Fn Total , and the fan defines a fan tip speed v tipspeed ;and The outlet guide vane cooling capacity (OGVCC) is greater than 0.01 and less than 13, where OGVCC is equal to: in 2. The gas turbine engine according to claim 1, characterized in that in, The OGVCC is greater than or equal to 0.01 and less than or equal to 6.

21.

3. The gas turbine engine according to claim 1, characterized in that in, The BPR is greater than or equal to 3 and less than or equal to 30.

4. The gas turbine engine according to claim 1, characterized in that in, The OGVCC is greater than or equal to 3.23 and less than or equal to 13, and wherein the BPR is greater than or equal to 13 and less than or equal to 30.

5. The gas turbine engine according to claim 1, characterized in that in, f OGV Greater than or equal to 0.05 and less than or equal to 20.

6. The gas turbine engine according to claim 1, characterized in that in, f OGV Greater than or equal to 0.05 and less than or equal to 5.

7. The gas turbine engine according to claim 1, characterized in that in, D fan greater than or equal to 0.5 m and less than or equal to 3.5 m, and where N vane Greater than or equal to 8 and less than or equal to 120.

8. The gas turbine engine according to claim 1, characterized in that in, ΔH is less than or equal to 927 meters.

9. The gas turbine engine according to claim 1, characterized in that in, T inlet is greater than or equal to 50 degrees Celsius and less than or equal to 250 degrees Celsius, and wherein T air Greater than or equal to -56.6 degrees Celsius and less than or equal to 60 degrees Celsius.

10. The gas turbine engine according to claim 1, characterized in that in, The heat transfer fluid is lubricating oil for the gas turbine engine.

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