Design method and system for matching opening mode of cap hood with air inlet of head of combustion chamber

Abstract

The invention relates to the field of aero-engines and gas turbines, and discloses a design method and system for matching a cap cover tapping mode with combustion chamber head air inflow, and cap cover holes are formed by communicating all head cap cover datum hole molded surfaces. The number of partitions between the datum hole molded surfaces of the adjacent cap covers can be reduced, the static pressure recovery coefficient is increased, flow stability is facilitated, airflow pulsation and overflow are avoided to the maximum extent, flow separation is reduced, meanwhile, the problems of air inlet interference and flow separation caused by impact of airflow on the partitions are avoided, and the flow stability and combustion performance of the combustion chamber are improved. Besides, the air inlet rectification requirement of the combustion chamber and the guiding effect of a flame tube head channel on airflow flowing are comprehensively considered, the design thought that the hole profile (hole number and shape setting) of the cap hood is coupled with combustion chamber head air inlet is provided, the design iteration period is effectively shortened, the development cost is reduced, and the matching performance of the cap hood and the flame tube head is improved; and the method has relatively high universality and operability.

Description

Technical Field

[0001] The invention relates to the field of aero engines and gas turbines, and discloses a design method and system for matching a cap opening mode with an air intake of a combustion chamber head. Background Art

[0002] The main combustion chamber is one of the three core working components of aircraft engines and ground-based gas turbines. Its design requirements require a high total pressure recovery coefficient, excellent combustion efficiency, low pollutant emissions, appropriate flow distribution and temperature distribution, and optimal combustion stability. The cap, a key component of the combustor, is responsible for guiding the compressor airflow into the flame tube and the inner and outer annular channels with minimal pressure loss. The rationality of the cap design directly affects the combustor's sensitivity to intake distortion and airflow stability, thereby affecting combustion performance.

[0003] Traditional cap shroud design is independent of the liner head structure, relying primarily on the designer's engineering experience without thorough consideration of its matching with the head intake, and employing a single aperture method. To reduce the difficulty of component and complete engine commissioning and iteration, shorten development cycles, optimize the flow field in the combustion chamber head, and reduce sensitivity to intake distortion, a rational and efficient design method for matching cap shroud apertures with the combustion chamber head intake is required. Summary of the Invention

[0004] The purpose of the present invention is to provide a design method and system for matching the cap opening mode with the combustion chamber head intake, which can avoid airflow pulsation and overflow to the greatest extent, reduce flow separation, and at the same time avoid the intake interference and flow separation problems caused by impact partition of the airflow, thereby improving the flow stability and combustion performance of the combustion chamber.

[0005] In order to achieve the above technical effects, the technical solution adopted by the present invention is:

[0006] A design method for matching a cap cover opening mode with a combustion chamber head intake, comprising:

[0007] According to the design profile of the cap, a cap reference hole is opened on the cap surface at a position facing the flame tube head, and the center of the cap reference hole is the intersection of the swirler central axis and the cap profile;

[0008] The cap opening area is obtained by analysis based on the area of ​​the swirler in the main combustion chamber and the swirler's flow coefficient.

[0009] According to the opening area of ​​the cap cover, grooves are cut on the cap cover to connect multiple adjacent cap cover reference holes to form cap cover holes. The number of cap cover holes is m=n / b, where n is the number of flame tube heads and b is a coefficient whose value range is 1 to 4.

[0010] Furthermore, the cap opening area Among them A s The area of ​​the swirler in the main combustion chamber, Cd s is the flow coefficient of the cyclone, Cd m is the design flow coefficient of the cap hole, k is the coefficient, and the value range of k is 1.4 to 2.

[0011] Furthermore, tangent arcs are made on the inner edges and outer sides of the multiple cap cover reference holes that need to be connected to each other, and the tangent arcs and the profile lines on both sides of the multiple cap cover reference holes that are connected to each other are combined to form the cap cover hole profile.

[0012] Furthermore, a lip is provided on the hole-profile surface of the cap cover, and the flange of the lip faces the incoming flow direction.

[0013] Furthermore, the angle between the central axis of the cap hole and the axial direction of the aircraft engine is in the range of [min(a k , a h ), max(a k , a h )], where a k is the angle between the central axis of the front diffuser and the axial direction of the aircraft engine, a h is the flame tube inclination angle.

[0014] To achieve the above technical effects, the present invention also provides a design system for matching the cap opening mode with the combustion chamber head intake, comprising:

[0015] A reference hole opening module is used to open a cap cover reference hole on the cap cover at a position facing the flame tube head according to the design profile of the cap cover, wherein the center of the cap cover reference hole is the intersection of the swirler central axis and the cap cover profile;

[0016] An area calculation module is used to analyze and obtain the cap opening area based on the area of ​​the swirler in the main combustion chamber and the flow coefficient of the swirler;

[0017] The forming control module is used to groove the cap cover according to the cap cover opening area to connect multiple adjacent cap cover reference holes to form cap cover holes, and the number of cap cover holes is m=n / b, where n is the number of flame tube heads and b is a coefficient, and the value range of b is 1 to 4.

[0018] Furthermore, in the area calculation module, the cap opening area Among them A s The area of ​​the swirler in the main combustion chamber, Cd s is the flow coefficient of the cyclone, Cd m is the design flow coefficient of the cap hole, k is the coefficient, and the value range of k is 1.4 to 2.

[0019] Furthermore, in the forming control module, tangent arcs are made on the inner edges and outer sides of multiple cap cover reference holes that need to be connected to each other, and the tangent arcs and the profile lines on both sides of the multiple cap cover reference holes that are connected to each other are combined to form the cap cover hole profile.

[0020] Furthermore, in the molding control module, a lip is provided on the hole-shaped surface of the cap, and the flange of the lip faces the incoming flow direction.

[0021] Furthermore, in the molding control module, the angle between the central axis of the cap hole and the axial direction of the aircraft engine is in the range of [min(a k , a h ), max(a k , a h )], where a k is the angle between the central axis of the front diffuser and the axial direction of the aircraft engine, a h is the flame tube inclination angle.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention connects the reference hole profiles of each head cap cover to form a cap cover hole, thereby reducing the number of partitions between adjacent cap cover reference hole profiles, improving the static pressure recovery coefficient, facilitating flow stability, minimizing airflow pulsation and overflow, reducing flow separation, and avoiding intake interference and flow separation caused by airflow impacting the partitions, thereby improving combustion chamber flow stability and combustion performance.

[0024] 2. The present invention comprehensively considers the requirements for combustion chamber intake rectification and the guiding effect of the flame tube head channel on the airflow, and proposes a design concept of coupling the cap cover hole surface with the combustion chamber head intake, which effectively shortens the design iteration cycle, reduces the development cost, improves the matching of the cap cover and the flame tube head, and has strong versatility and operability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Flowchart of the design method for matching the cap cover opening method with the combustion chamber head intake in Example 1 or 2;

[0026] Figure 2 A block diagram of the system structure for designing the matching between the cap opening method and the combustion chamber head intake in Example 1 or 2;

[0027] Figure 3 Schematic diagram of the cap cover and its cap cover hole structure obtained in Example 1 or 2;

[0028] Figure 4 This is a schematic diagram of the first structural form of the cap cover surface in Example 2;

[0029] Figure 5This is a schematic diagram of the second structure of the cap profile in Example 2;

[0030] Figure 6 Schematic diagram of the third structure of the cap profile in Example 2;

[0031] Figure 7 Schematic diagram of the fourth structure of the cap profile in Example 2;

[0032] Among them, 1. cap cover reference hole; 2. cap cover hole; 3. lip; 4. nozzle disassembly hole; 5. reference hole opening module; 6. area calculation module; 7. forming control module. DETAILED DESCRIPTION

[0033] The present invention will be described in further detail below with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the present invention to the following embodiments, as all technologies implemented based on the present invention fall within the scope of the present invention.

[0034] Example 1

[0035] See also Figure 1-Figure 3 A design method for matching a cap cover opening mode with a combustion chamber head intake, comprising:

[0036] According to the design profile of the cap, a cap reference hole is opened on the cap surface at a position facing the flame tube head, and the center of the cap reference hole is the intersection of the swirler central axis and the cap profile;

[0037] The cap opening area is obtained by analysis based on the area of ​​the swirler in the main combustion chamber and the swirler's flow coefficient.

[0038] According to the opening area of ​​the cap cover, grooves are cut on the cap cover to connect multiple adjacent cap cover reference holes to form cap cover holes. The number of cap cover holes is m=n / b, where n is the number of flame tube heads and b is a coefficient whose value range is 1 to 4.

[0039] In this embodiment, by connecting the reference hole profiles of each head cap cover to form a cap cover hole, the number of partitions between adjacent cap cover reference hole profiles is reduced, the static pressure recovery coefficient is improved, and flow stability is promoted. Airflow pulsation and overflow are minimized, flow separation is reduced, and intake interference and flow separation caused by airflow impact partitions are avoided, thereby improving combustion chamber flow stability and combustion performance. In addition, this embodiment comprehensively considers the combustion chamber intake rectification requirements and the guiding effect of the flame tube head channel on airflow, and proposes a design concept that couples the cap cover hole profile (hole number and shape setting) with the combustion chamber head intake. This effectively shortens the design iteration cycle, reduces development costs, improves the compatibility of the cap cover and the flame tube head, and has strong versatility and operability.

[0040] In this embodiment, grooves can be cut on the cap cover to connect multiple adjacent cap cover reference holes to form a cap cover hole, and then three-dimensional simulation analysis can be used to check the total pressure loss coefficient of the combustion chamber and the local flow field stability from the pre-diffuser to the downstream of the swirler. If the design requirements are not met, the various structural parameters of the cap cover can be readjusted until the simulation prediction results meet the flow field stability design requirements, thereby realizing a design closed loop in which the combustion chamber head intake and the cap cover hole provide mutual feedback.

[0041] Based on the same inventive concept, this embodiment also provides a design system for matching the cap opening method with the combustion chamber head intake, including:

[0042] A reference hole opening module is used to open a cap cover reference hole on the cap cover at a position facing the flame tube head according to the design profile of the cap cover, wherein the center of the cap cover reference hole is the intersection of the swirler central axis and the cap cover profile;

[0043] An area calculation module is used to analyze and obtain the cap opening area based on the area of ​​the swirler in the main combustion chamber and the flow coefficient of the swirler;

[0044] The forming control module is used to groove the cap cover according to the cap cover opening area to connect multiple adjacent cap cover reference holes to form cap cover holes, and the number of cap cover holes is m=n / b, where n is the number of flame tube heads and b is a coefficient, and the value range of b is 1 to 4.

[0045] Example 2

[0046] See also Figure 1 、 Figure 3 This embodiment takes the cap hole design on a certain type of combustion chamber cap structure as an example to describe in detail the cap hole opening method and the combustion chamber head intake matching design method process of the present invention, which specifically includes the following steps:

[0047] Step 1: according to the design profile of the cap, a cap reference hole is opened on the cap surface at a position facing the flame tube head, wherein the center of the cap reference hole is the intersection of the swirler central axis and the cap profile;

[0048] The cap surface in this embodiment is constructed using a three-segment arc method based on the pre-diffuser of the combustion chamber, the inner and outer ring structures of the flame tube, the nozzle installation method, the operating conditions and operating environment of the combustion chamber; then a cap reference hole is opened on the cap surface facing the head of the flame tube, where the center of the cap reference hole is the intersection of the central axis of the swirler and the cap surface.

[0049] Step 2: Analyze and obtain the cap opening area based on the area of ​​the swirler in the main combustion chamber and the flow coefficient of the swirler;

[0050] In this embodiment, the cap opening area Among them A s The area of ​​the swirler in the main combustion chamber, Cd s is the flow coefficient of the cyclone, Cd m is the design flow coefficient of the cap hole, k is the coefficient, and the value range of k is 1.4 to 2. In this example, the value of k is 1.6.

[0051] Step three: according to the opening area of ​​the cap cover, grooves are made on the cap cover to connect multiple adjacent cap cover reference holes to form cap cover holes, the number of the cap cover holes is m=n / b, wherein n is the number of flame tube heads and b is a coefficient. When n≤14, b takes a value of 1 to 2; when n>14 and the air flow entering the combustion chamber is stable (speed fluctuation is less than 5% of the average speed) and the pulsation is low (turbulence intensity is less than 10%), b takes a value of 1 to 2; when n>14 and the engine operating conditions are relatively severe (speed fluctuation is greater than 5% of the average speed), b takes a value of 2 to 4.

[0052] In this embodiment, tangent arcs are made on the inner and outer edges of the multiple cap cover reference holes that need to be connected to each other. The tangent arcs and the profile lines on both sides of the multiple cap cover reference holes that are connected to each other form the cap cover hole profile. The specific form of the tangent arcs is as follows: Figure 4-Figure 7 The structure in the end is designed to meet the requirements of the cap opening area and the number of cap holes.

[0053] In this embodiment, a lip is provided on the cap hole profile, with the flange of the lip facing the incoming flow direction to guide the gas to achieve diversion with lower pressure loss. In this embodiment, a nozzle disassembly hole is also required to be reserved on the upper edge of the cap hole.

[0054] In this embodiment, the angle between the central axis of the cap hole and the axial direction of the aircraft engine is in the range of [min(a k , a h ), max(a k , a h )], where a k is the angle between the central axis of the front diffuser and the axial direction of the aircraft engine, a h The flame tube inclination angle a in this embodiment h =0°, the inclination angle of the cap hole surface a 帽罩 =0°.

[0055] Step 4. Add the three-dimensional model of the cap structure designed according to the operating procedures of steps 1 to 3 to the three-dimensional model of the combustion chamber, and use three-dimensional simulation analysis to verify the total pressure loss coefficient of the combustion chamber and the stability of the local flow field from the pre-diffuser to the downstream of the swirler; the three-dimensional simulation results show that the gas flowing out of the diffuser is rectified twice after passing through the cap, and the cap can realize the diversion of air according to the flow distribution requirements, and there is no obvious separation at the profile. Compared with the method of only a single head with independent openings, the cap hole profile design method of this embodiment has a better rectification effect, which is beneficial to improving the flow field stability and combustion performance of the combustion chamber head.

[0056] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A design method for matching the cap opening mode with the combustion chamber head intake, characterized in that: include: According to the design profile of the cap, a cap reference hole is opened on the cap surface at a position facing the flame tube head, and the center of the cap reference hole is the intersection of the swirler central axis and the cap profile; The cap opening area is obtained by analysis based on the area of ​​the swirler in the main combustion chamber and the swirler's flow coefficient. According to the opening area of ​​the cap cover, grooves are cut on the cap cover to connect multiple adjacent cap cover reference holes to form cap cover holes. The number of cap cover holes is m=n / b, where n is the number of flame tube heads and b is a coefficient whose value range is 1 to 4.

2. The design method for matching the cap cover opening mode with the combustion chamber head intake according to claim 1 is characterized in that: Cap opening area Among them A s The area of ​​the swirler in the main combustion chamber, Cd s is the flow coefficient of the cyclone, Cd m is the design flow coefficient of the cap hole, k is the coefficient, and the value range of k is 1.4 to 2.

3. The design method for matching the cap opening mode with the combustion chamber head air intake according to claim 1 is characterized in that: Tangent arcs are made on the inner edges and outer sides of multiple cap cover reference holes that need to be connected to each other, and the tangent arcs and the profile lines on both sides of the multiple cap cover reference holes that are connected to each other are combined to form the cap cover hole profile.

4. The design method for matching the cap cover opening mode with the combustion chamber head intake according to claim 3 is characterized in that: A lip is provided on the hole surface of the cap cover, and the flange of the lip faces the incoming flow direction.

5. The design method for matching the cap cover opening mode with the combustion chamber head intake according to claim 1 is characterized in that: The range of the angle between the central axis of the cap hole and the axial direction of the aircraft engine is [min(a k , a h ), max(a k , a h )], where a k is the angle between the central axis of the front diffuser and the axial direction of the aircraft engine, a h is the flame tube inclination angle.

6. A system for designing a matching method between the cap opening mode and the combustion chamber head intake, characterized in that: include: A reference hole opening module is used to open a cap cover reference hole on the cap cover at a position facing the flame tube head according to the design profile of the cap cover, wherein the center of the cap cover reference hole is the intersection of the swirler central axis and the cap cover profile; An area calculation module is used to analyze and obtain the cap opening area based on the area of ​​the swirler in the main combustion chamber and the flow coefficient of the swirler; The forming control module is used to groove the cap cover according to the cap cover opening area to connect multiple adjacent cap cover reference holes to form cap cover holes, and the number of cap cover holes is m=n / b, where n is the number of flame tube heads and b is a coefficient, and the value range of b is 1 to 4.

7. The cap cover opening method and combustion chamber head air intake matching design system according to claim 6 is characterized in that: In the area calculation module, the cap opening area Among them A s The area of ​​the swirler in the main combustion chamber, Cd s is the flow coefficient of the cyclone, Cd m is the design flow coefficient of the cap hole, k is the coefficient, and the value range of k is 1.4 to 2.

8. The cap cover opening method and combustion chamber head air intake matching design system according to claim 6 is characterized in that: In the forming control module, tangent arcs are made on the inner edges and outer sides of multiple cap cover reference holes that need to be connected to each other, and the tangent arcs and the profile lines on both sides of the multiple cap cover reference holes that are connected to each other are combined to form the cap cover hole profile.

9. The cap cover opening method and combustion chamber head air intake matching design system according to claim 8 is characterized in that: In the molding control module, a lip is provided on the hole-shaped surface of the cap, and the flange of the lip faces the incoming flow direction.

10. The cap cover opening method and combustion chamber head air intake matching design system according to claim 6, characterized in that: In the molding control module, the angle between the central axis of the cap hole and the axial direction of the aircraft engine is in the range of [min(a k , a h ), max(a k , a h )], where a k is the angle between the central axis of the front diffuser and the axial direction of the aircraft engine, a h is the flame tube inclination angle.

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