Super combustion chamber with adjustable duct area and mode conversion method

Abstract

The invention belongs to the field of aero-engines, and provides a super combustion chamber with an adjustable duct area and a mode conversion method.The super combustion chamber comprises a duct area adjusting structure, a flame stabilizer and an inner / outer fuel injection system, and the duct area adjusting structure comprises an outer duct casing, an inner duct casing and a heat insulation screen; an angle-adjustable outer ejector is arranged at the tail end of the outer culvert casing in the airflow direction, and an angle-adjustable inner ejector is arranged at the tail end of the inner culvert casing in the airflow direction. The flame stabilizer is arranged behind the duct area adjusting structure in the airflow direction. The internal fuel injection system is arranged in the flame stabilizer, and a fuel injection hole is formed in the flame stabilizer; and the external fuel injection system is arranged outside the flame stabilizer. According to the designed super combustion chamber, free switching and stable work of the turbine mode, the turbine outer culvert deflation mode, the transition mode and the stamping mode are well achieved, and the requirement for stable work of the super combustion chamber in the wide Mach number range is met.

Description

Technical Field

[0001] The present invention belongs to the field of aeroengines, relates to the design technology of a scram combustor, and particularly relates to a scram combustor with adjustable duct area and a mode conversion method. Background Art

[0002] A combined engine is usually composed of a turbine and a ramjet engine. It combines the advantages of a turbine engine and a ramjet engine, has the ability of conventional horizontal takeoff and landing, has advantages such as high specific impulse and reusability, and has the working ability in a wide speed range and a large airspace from zero speed on the ground to hypersonic speed in the near space. It is an ideal power form for a horizontal takeoff and landing hypersonic aircraft.

[0003] Among them, a scram combustor is a key component of a combined engine. Compared with a single-mode afterburner of a traditional turbojet or turbofan engine, a scram combustor generally has three or more ducts, and it needs to achieve free switching and stable operation under different modes such as a turbine mode, a transition mode, and a ram mode under complex oncoming flow conditions. This requires that the flow area of each duct is variable or even the duct can be completely closed and switched. To achieve mode switching, a rear duct ejector is essential. At present, there is no good solution for the structure of a three-duct scram combustor at home and abroad. Although the rear duct ejector of a traditional variable cycle engine can achieve a limited variable flow area, it cannot achieve complete closure and switching of the duct. Summary of the Invention

[0004] In order to solve the technical problems of the existing mode conversion requirements of a three-duct scram combustor, the present invention discloses a scram combustor with adjustable duct area, and the scram combustor includes:

[0005] A duct area adjustment structure, which is located in the duct formed by an outer casing and a diffuser. The duct area adjustment structure includes an outer duct casing, an inner duct casing, and a heat insulation screen. A ram duct is formed between the outer casing and the outer duct casing, an outer duct is formed between the outer duct casing and the inner duct casing, a turbine duct is formed between the inner duct casing and the diffuser. An angle-adjustable outer ejector is provided at the end of the outer duct casing along the air flow direction, and an angle-adjustable inner ejector is provided at the end of the inner duct casing along the air flow direction;

[0006] A flame stabilizer, which is arranged behind the duct area adjustment structure along the air flow direction. The inner side of the flame stabilizer is connected to the diffuser, and the outer side is connected to the heat insulation screen. A cooling channel is formed between the outer casing and the heat insulation screen, and the inner ejector, the diffuser, and the heat insulation screen form an inner duct;

[0007] An internal fuel injection system, which is arranged in the flame stabilizer, and fuel injection holes are provided on the flame stabilizer;

[0008] An external fuel injection system, which is arranged outside the flame stabilizer.

[0009] Furthermore, during the angle adjustment process of the external ejector and the internal ejector, the end of the external ejector contacts or separates from the outer casing or the inner casing, and the end of the internal ejector contacts or separates from the heat shield or the diffuser.

[0010] Furthermore, the included angle between the inner side of the flame stabilizer and the heat shield along the air flow direction is an acute angle.

[0011] Furthermore, the flame stabilizer includes a long radial stabilizer, a short radial stabilizer, and an annular pilot flame stabilizer. The annular pilot flame stabilizer is coaxial with the diffuser. A plurality of long radial stabilizers are arranged through the annular pilot flame stabilizer along the diameter direction, and short radial stabilizers are arranged between adjacent two long radial stabilizers on the outer peripheral wall of the annular pilot flame stabilizer.

[0012] Even further, a plurality of the fuel injection holes are arranged on both side surfaces of the long radial stabilizer and the short radial stabilizer, and the hole pitch between two adjacent fuel injection holes along the diameter direction gradually shortens.

[0013] Even further, the cross-sectional shape of the annular pilot flame stabilizer includes a first expansion section, a stabilizer straight section, and a second expansion section along the air flow direction.

[0014] Even further, the diffuser includes a first diffuser straight section and a diffuser contraction section along the air flow direction. The included angle between the outer wall of the diffuser contraction section and the long radial stabilizer is 1° to 30°.

[0015] The embodiment of the present invention also provides a method for mode conversion of a super combustor with adjustable duct area, which is used for mode conversion of the above-mentioned super combustor, and includes the following steps:

[0016] In the turbine mode, control the external ejector to rotate so that the end of the external ejector contacts the inner wall, and close the ram duct; control the internal ejector to rotate so that the end of the internal ejector contacts the heat shield, completely isolate the cooling channel from the inner flow path, all the external flow enters the cooling channel, and all the turbine flow enters the inner flow path;

[0017] When the cooling channel cannot completely pass the external flow, keep the position of the external ejector unchanged, control the internal ejector to rotate towards the diffuser direction, connect the cooling channel with the inner flow path, and switch from the turbine mode to the turbine external bleed mode conversion;

[0018] The process of switching the turbine bypass bleeding mode to the ram mode is defined as the transition mode. Keep the cooling channel connected to the core, control the external ejector to rotate towards the core casing to open the ram duct, so that the bypass airflow and the ram airflow enter the cooling channel and the core simultaneously.

[0019] When the end of the external ejector contacts the core casing, the ram duct is fully opened and the bypass is fully closed. Control the internal ejector to rotate until it contacts the diffuser to fully close the turbine duct, and enter the ram mode.

[0020] Furthermore, when the super combustor is in the turbine mode and the turbine bypass bleeding mode, fuel is provided by the internal fuel injection system; when the super combustor is in the transition mode, fuel is provided by the internal fuel injection system and the external fuel injection system; when the super combustor is in the ram mode, fuel is provided by the external fuel injection system.

[0021] Even further, during the process of switching the turbine bypass bleeding mode to the ram mode, the fuel supply of the internal fuel injection system gradually decreases, the fuel supply of the external fuel injection system gradually increases, and the total fuel supply of the internal fuel injection system and the external fuel injection system remains unchanged.

[0022] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above technical solutions adopted in the embodiments of this specification at least include:

[0023] The super combustor structure designed by the present invention meets the working requirements of a three-duct super combustor. Innovatively, a double-ejector structure form is proposed, and an organized combustion structure with long / short radial stabilizers, an annular pilot flame stabilizer, and a conical diffuser is adopted. By setting two sets of fuel injection systems suitable for different modal environments, a super combustor structure with a rear duct ejector is formed, which better realizes the stable operation and free switching of the conventional turbine mode, turbine bypass bleeding mode, transition mode, and ram mode, and meets the working requirements of the complex working environment of the super combustor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a three-dimensional view of a super combustor with adjustable duct area disclosed in an embodiment of the present invention;

[0026] Figure 2 Cross-sectional view of a super combustor with adjustable duct area disclosed in an embodiment of the present invention;

[0027] Figure 3 Schematic diagram of a flame stabilizer and a diffuser disclosed in an embodiment of the present invention;

[0028] Figure 4 Cross-sectional schematic diagram of an annular pilot flame stabilizer disclosed in an embodiment of the present invention;

[0029] Figure 5 Schematic diagram of the positions of an external ejector and an internal ejector in the turbine mode disclosed in an embodiment of the present invention;

[0030] Figure 6 Schematic diagram of the positions of an external ejector and an internal ejector in the turbine bypass bleed mode disclosed in an embodiment of the present invention;

[0031] Figure 7 Schematic diagram of the positions of an external ejector and an internal ejector in the transition mode disclosed in an embodiment of the present invention;

[0032] Figure 8 Schematic diagram of the positions of an external ejector and an internal ejector in the ram mode disclosed in an embodiment of the present invention;

[0033] Wherein, 1, outer casing; 2, bypass casing; 3, core casing; 4, heat shield; 5, diffuser; 51, first diffuser straight section; 52, diffuser contraction section; 6, external ejector; 7, internal ejector; 8, flame stabilizer; 9, internal fuel injection system; 10, ram duct; 11, bypass; 12, turbine duct; 13, cooling channel; 14, core; 15, external fuel injection system; 16, long radial stabilizer; 17, short radial stabilizer; 18, annular pilot flame stabilizer; 181, first expansion section; 182, stabilizer straight section; 183, second expansion section; 20, fuel injection hole. Detailed implementation manners

[0034] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0035] The following describes the implementation manners of the present application through specific examples. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation manners, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features of the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope protected by the present application.

[0036] An embodiment of the present invention provides a super combustor with adjustable duct area. Refer to Figure 1 As shown, the super combustor includes a duct area adjustment structure, a flame stabilizer 8, an internal fuel injection system 9, and an external fuel injection system 15.

[0037] Among them, refer to Figure 1 and Figure 2 As shown, the duct area adjustment structure is located in the duct formed by the outer casing 1 and the diffuser 5, and includes an outer duct casing 2, an inner duct casing 3, and a heat insulation screen 4. A ram duct 10 is formed between the outer casing 1 and the outer duct casing 2, an outer duct 11 is formed between the outer duct casing 2 and the inner duct casing 3, a turbine duct 12 is formed between the inner duct casing 3 and the diffuser 5. An angle-adjustable outer ejector 6 is provided at the end of the outer duct casing 2 along the air flow direction, and an angle-adjustable inner ejector 7 is provided at the end of the inner duct casing 3 along the air flow direction.

[0038] Refer to Figure 1 and Figure 2 As shown, the flame stabilizer 8 is arranged behind the duct area adjustment structure along the air flow direction. The inner side of the flame stabilizer 8 is connected to the diffuser 5, and the outer side is connected to the heat insulation screen 4. A cooling channel 13 is formed between the outer casing 1 and the heat insulation screen 4. The inner ejector 7, the diffuser 5, and the heat insulation screen 4 form an inner duct 14;

[0039] Refer to Figure 2 As shown, the internal fuel injection system 9 is arranged in the flame stabilizer 8, and fuel injection holes 20 are provided on the flame stabilizer 8. The external fuel injection system 15 is arranged outside the flame stabilizer 8.

[0040] Furthermore, both the outer ejector 6 and the inner ejector 7 are flat plate structures, one end of which is rotatably arranged on the corresponding casing, and is controlled to rotate around the connection point through an angle drive structure to open or close the corresponding channel.

[0041] Further, as shown in Figure 1 and Figure 2 During the angle adjustment process of the external ejector 6 and the internal ejector 7, the end of the external ejector 6 of the external ejector 6 contacts or separates from the outer casing 1 or the core casing 3, and the end of the internal ejector 7 contacts or separates from the heat shield 4 or the diffuser 5.

[0042] Further, as shown in Figure 1 The included angle between the inner side of the flame stabilizer 8 and the heat shield 4 along the gas flow direction is an acute angle. By designing the flame stabilizer 8 with a rear inclination angle, it has a certain flow distribution effect, which is more conducive to gas flow distribution and makes the gas flow tend to flow close to the surface of the diffuser 5. This angle can be represented by α, and preferably α ≤ 60°.

[0043] Further, as shown in Figure 3 The flame stabilizer 8 includes a long radial stabilizer 16, a short radial stabilizer 17, and an annular pilot flame stabilizer 18. The annular pilot flame stabilizer 18 is coaxial with the diffuser 5. A plurality of long radial stabilizers 16 are provided through the annular pilot flame stabilizer 18 along the diameter direction, and short radial stabilizers 17 are provided between adjacent two long radial stabilizers 16 on the outer peripheral wall of the annular pilot flame stabilizer 18.

[0044] Furthermore, as shown in Figure 3 A plurality of fuel injection holes 20 are provided on both side surfaces of the long radial stabilizer 16 and the short radial stabilizer 17, and the hole pitch between two adjacent fuel injection holes 20 along the diameter direction gradually decreases.

[0045] Furthermore, as shown in Figure 4 The cross-sectional shape of the annular pilot flame stabilizer 18 includes a first expansion section 181, a stabilizer straight section 182, and a second expansion section 183 along the gas flow direction. Among them, the cross-sectional shapes of the long radial stabilizer 16 and the short radial stabilizer 17 are the same as that of the annular pilot flame stabilizer 18. This structure can play a role in flow distribution and flow guiding, making the gas flow tend to flow close to the surface of the diffuser 5 and suppressing the flow separation on the diffuser surface.

[0046] Furthermore, the diffuser 5 adopts a truncated cone structure form. As shown in Figure 1 The diffuser 5 includes a first diffuser straight section 51 and a diffuser contraction section 52 along the gas flow direction. This structure can be better applied to the organization of combustion and flame transmission under the conditions of high-temperature and high-speed incoming flow. The included angle between the outer wall of the diffuser contraction section 52 and the long radial stabilizer 16 is 1° - 30°.

[0047] An embodiment of the present invention also provides a method for mode conversion of a super combustor with adjustable duct area. The method is used for mode conversion of the above super combustor, and includes the following steps:

[0048] Refer to Figure 5 As shown, in the turbine mode, control the rotation of the external ejector 6 so that the end of the external ejector 6 contacts the inner wall, and close the ram duct 10; control the rotation of the internal ejector 7 so that the end of the internal ejector 7 contacts the heat shield 4, completely isolate the cooling channel 13 from the core flow 14, all the external flow b enters the cooling channel 13, and all the turbine flow a enters the core flow 14.

[0049] Refer to Figure 6 As shown, when the cooling channel 13 cannot completely pass the external flow, keep the position of the external ejector 6 unchanged, control the internal ejector 7 to rotate towards the diffuser 5, connect the cooling channel 13 with the core flow 14, and switch from the turbine mode to the turbine external bleed mode conversion. At this time, the part of the external flow b that cannot pass through the cooling channel 13 enters the core flow 14, realizing the adaptive adjustment of the super combustor.

[0050] Refer to Figure 7 As shown, the process of switching the turbine external bleed mode to the ram mode is defined as the transition mode. Keep the cooling channel 13 connected to the core flow 14, control the external ejector 6 to rotate towards the core casing 3 to open the ram duct 10, so that the external flow b and the ram flow c enter the cooling channel 13 and the core flow 14 at the same time.

[0051] Refer to Figure 8 As shown, when the end of the external ejector 6 contacts the core casing 3, the ram duct 10 is completely opened, the external duct 11 is completely closed, control the internal ejector 7 to rotate until it contacts the diffuser 5 to completely close the turbine duct 12, and enter the ram mode. At this time, only the ram flow c can enter the cooling channel 13 and the core flow 14.

[0052] Further, when the super combustor is in the turbine mode and the turbine external bleed mode, fuel is provided by the internal fuel injection system 9 to meet the working requirements of the high-temperature and high-flow-rate incoming flow. When the super combustor is in the transition mode, fuel is provided by the internal fuel injection system 9 and the external fuel injection system 15; when the super combustor is in the ram mode, fuel is provided by the external fuel injection system 15 to meet the working requirements of the low-temperature and high-flow-rate incoming flow.

[0053] Furthermore, during the process of the turbine bypass bleed mode switching to the ramjet mode, the fuel supply of the internal fuel injection system 9 gradually decreases, the fuel supply of the external fuel injection system 15 gradually increases, and the total fuel supply of the internal fuel injection system 9 and the external fuel injection system 15 remains unchanged.

[0054] The super combustion chamber structure designed in the present invention meets the working requirements of a three-bypass super combustion chamber. It innovatively proposes a double-ejector structural form, and adopts a combustion organization structure with long / short radial stabilizers, an annular pilot flame stabilizer, and a conical diffuser. By setting two sets of fuel injection systems suitable for different modal environments, a super combustion chamber structure with a rear bypass ejector is formed, which preferably realizes the stable operation and free switching of the conventional turbine mode, the turbine bypass bleed mode, the transition mode, and the ramjet mode, and meets the working requirements of the complex working environment of the super combustion chamber.

[0055] Obviously, those skilled in the art should understand that the above are only preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, various changes and modifications can be made to the embodiments of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A scramjet combustor with adjustable duct area, characterized in that, Comprising: A duct area adjustment structure, which is located in the duct formed by the outer casing (1) and the diffuser (5), and includes an outer duct casing (2), an inner duct casing (3) and a heat insulation screen (4). A ram duct (10) is formed between the outer casing (1) and the outer duct casing (2), an outer duct (11) is formed between the outer duct casing (2) and the inner duct casing (3), a turbine duct (12) is formed between the inner duct casing (3) and the diffuser (5). An angle-adjustable outer ejector (6) is provided at the end of the outer duct casing (2) along the air flow direction, and an angle-adjustable inner ejector (7) is provided at the end of the inner duct casing (3) along the air flow direction; A flame stabilizer (8), which is arranged behind the duct area adjustment structure along the air flow direction. The inner side of the flame stabilizer (8) is connected to the diffuser (5), and the outer side is connected to the heat insulation screen (4). A cooling channel (13) is formed between the outer casing (1) and the heat insulation screen (4). The inner ejector (7), the diffuser (5) and the heat insulation screen (4) form an inner duct (14); An internal fuel injection system (9), which is arranged in the flame stabilizer (8), and fuel injection holes (20) are provided on the flame stabilizer (8); An external fuel injection system (15), which is arranged outside the flame stabilizer (8).

2. The super combustor with adjustable duct area according to claim 1, characterized in that During the angle adjustment process of the outer ejector (6) and the inner ejector (7), the end of the outer ejector (6) contacts or separates from the outer casing (1) or the inner duct casing (3), and the end of the inner ejector (7) contacts or separates from the heat insulation screen (4) or the diffuser (5).

3. The variable-duct-area super combustor according to claim 1, wherein The included angle between the inner side of the flame stabilizer (8) and the heat insulation screen (4) along the air flow direction is an acute angle.

4. The super combustor with adjustable duct area according to claim 1, characterized in that The flame stabilizer (8) includes a long radial stabilizer (16), a short radial stabilizer (17) and an annular pilot flame stabilizer (18). The annular pilot flame stabilizer (18) is coaxial with the diffuser (5). A plurality of long radial stabilizers (16) penetrate through the annular pilot flame stabilizer (18) along the diameter direction, and short radial stabilizers (17) are provided on the outer peripheral wall of the annular pilot flame stabilizer (18) and between adjacent two long radial stabilizers (16).

5. The super combustor with adjustable duct area according to claim 4, characterized in that, Both side surfaces of the long radial stabilizer (16) and the short radial stabilizer (17) are provided with a plurality of the fuel injection holes (20), and the hole spacing between two adjacent fuel injection holes (20) along the diameter direction gradually shortens.

6. The variable-duct-area super combustor according to claim 5, wherein The cross-sectional shape of the annular pilot flame stabilizer (18) includes a first expansion section (181), a stabilizer straight section (182) and a second expansion section (183) along the air flow direction.

7. The adjustable-duct-area super combustor according to claim 4, wherein The diffuser (5) includes a first diffuser straight section (51) and a diffuser contraction section (52) along the air flow direction. The included angle between the outer wall of the diffuser contraction section (52) and the long radial stabilizer (16) is 1° to 30°.

8. A method for mode conversion of a super combustion chamber with adjustable duct area, characterized in that, For performing mode conversion on the super combustor described in any one of claims 1 to 7, the method includes: In the turbine mode, control the outer ejector (6) to rotate so that the end of the outer ejector (6) contacts the inner wall, and close the ram duct (10); control the inner ejector (7) to rotate so that the end of the inner ejector (7) contacts the heat shield (4), completely isolate the cooling channel (13) from the core flow (14), all the outer flow enters the cooling channel (13), and all the turbine flow enters the core flow (14); When the outer flow cannot fully flow through the cooling channel (13), keep the position of the outer ejector (6) unchanged, control the inner ejector (7) to rotate towards the diffuser (5), connect the cooling channel (13) to the core flow (14), and switch from the turbine mode to the turbine outer bleed mode conversion; Define the process of switching from the turbine outer bleed mode to the ram mode as the transition mode, keep the cooling channel (13) connected to the core flow (14), control the outer ejector (6) to rotate towards the core casing (3) to open the ram duct (10), so that the outer flow and the ram flow enter the cooling channel (13) and the core flow (14) simultaneously; When the end of the outer ejector (6) contacts the core casing (3), the ram duct (10) is fully opened, the outer duct (11) is fully closed, control the inner ejector (7) to rotate until it contacts the diffuser (5) to completely close the turbine duct (12), and enter the ram mode.

9. The modal conversion method of the ducted area adjustable super combustor according to claim 8, characterized in that When the super combustor is in the turbine mode and the turbine outer bleed mode, fuel is provided by the internal fuel injection system (9); when the super combustor is in the transition mode, fuel is provided by the internal fuel injection system (9) and the external fuel injection system (15); when the super combustor is in the ram mode, fuel is provided by the external fuel injection system (15).

10. The modal conversion method of the ducted area adjustable super combustor according to claim 9, characterized in that, During the process of switching from the turbine outer bleed mode to the ram mode, the fuel supply of the internal fuel injection system (9) gradually decreases, the fuel supply of the external fuel injection system (15) gradually increases, and the total fuel supply of the internal fuel injection system (9) and the external fuel injection system (15) remains unchanged.

Images