Bird impact test device for simulating real engine

Abstract

The invention belongs to the field of bird impact tests, and relates to a bird impact test device for simulating a real engine, which comprises a gas gun, a first ejection plate, a second ejection plate, a first fixed bracket, an air inlet casing and a second fixed bracket, the first ejection plate and the second ejection plate are arranged front and back, and the first fixing support and the air inlet casing are both located behind the second ejection plate; the air inlet casing is installed on the first fixing support. A fan casing is fixed on the second fixed bracket; by arranging a first ejection plate, a second ejection plate, a fixing support for simulating the influence of a first simulation fan blade on a fan casing and a component unit body after being impacted by a bird, an air inlet casing and a second fixing support, the ejection impact effect of an air inlet channel on a bird body is simulated, the process that the bird body impacts an air inlet supporting plate is simulated, and the bird body can be effectively simulated under the condition that the space is limited. And the change of the bird body motion trail and the cutting deceleration effect of the air inlet support plate on the bird body are effectively simulated, so that the capability of the engine for bearing the bird body impact is accurately evaluated.

Description

Technical Field

[0001] The present application belongs to the field of bird strike tests, and in particular to a bird strike test device for simulating a real engine. Background Art

[0002] An accident caused by an airplane or other aircraft colliding with a flying bird while flying in the air is called a bird strike. Bird strikes can lead to serious flight accidents. With the continuous development of aviation technology, the occurrence of bird strikes has been on the rise worldwide in recent years, especially for military aircraft flying at low altitudes and high speeds.

[0003] The extent of an aircraft bird strike accident depends mainly on factors such as the part of the aircraft hit by the bird, the mass of the bird, and the relative speed between the bird and the aircraft. According to statistics on bird strike incidents, the number of bird strikes on engine blades is second only to windshields, accounting for 18.0% of the total number of bird strikes. After a bird strike, the aircraft engine blades deform and break, causing the engine thrust to drop. The broken blades may also injure other blades and break them. Once the broken blades fly out and penetrate the casing, they will destroy the aircraft control system. Broken blades can also cause the engine rotor to be unbalanced, with extremely serious consequences, directly affecting the flight safety of the aircraft, causing huge economic losses, and also endangering the lives of the passengers.

[0004] The ability of aircraft engines to resist bird strikes is an important condition for ensuring aircraft safety. Bird strikes have always been one of the important items considered in engine airworthiness reviews. In airworthiness regulations, aircraft engines must undergo rigorous bird strike tests to assess their ability to withstand bird strikes. The ability of aircraft engines to resist bird strikes is a necessary condition for engines to obtain certification. Domestic and foreign airworthiness standards are constantly updated to improve aircraft's level of prevention of bird strikes.

[0005] The engine fan rotor bird strike test piece uses a fan rotor of a certain engine structure, which is a large fan rotor. After dynamic balancing, the test piece is installed on the test fulcrum of the horizontal rotor rotation tester in a simple support manner and connected to the double fulcrum of the equipment through a coupling. The test equipment consists of a horizontal rotor rotation tester and an air gun. The schematic diagram of the test equipment is shown in Figure 1 During the test, the firing mechanism is turned on after the fan rotor speed reaches the target value, and the compressed air pushes the shell and birdshot to accelerate in the barrel. After reaching the shell separation mechanism, the shell is separated and stops moving. The separated birdshot hits the designated position of the rotating fan rotor.

[0006] The existing bird strike test equipment has many deficiencies, mainly in terms of technology:

[0007] 1. When a real aircraft swallows a bird, the bird body first collides with the air inlet at high speed and rebounds, especially for aircraft engines with S-bend air inlets, which cannot be simulated by existing test equipment;

[0008] 2. After the bird body collides with the air intake duct, it continues to hit the engine intake casing support plate and guide vanes, and the bird body's mass and speed will decay, which cannot be simulated by the existing test equipment;

[0009] 3. Due to the lack of a fan casing, the bird body hit the rotating fan rotor blades, and the damage to the fan casing caused by the blades falling off is difficult to assess;

[0010] Based on the above three points, it is difficult for existing test equipment to simulate the test results of a real engine being hit by a bird. The existing test equipment adopts the most demanding assessment method of direct bird impact on the fan blades, which does not accurately assess the engine's ability to withstand bird impacts. Summary of the invention

[0011] The purpose of the present application is to provide a bird strike test device that simulates a real engine, so as to solve the problem of inaccurate evaluation of the engine's ability to withstand bird strikes.

[0012] The technical solution of the present application is: a bird strike test device for simulating a real engine, comprising an air gun, a first ejection plate, a second ejection plate, a first fixed bracket, an air intake casing and a second fixed bracket; the outlet of the air gun is arranged corresponding to the first ejection plate and the second ejection plate; the first ejection plate and the second ejection plate are arranged front and rear, and the first fixed bracket and the air intake casing are both located behind the second ejection plate, so as to simulate the air intake duct of the aircraft; and the air intake casing is installed on the first fixed bracket, so as to simulate the process of a bird body hitting the air intake support plate; a fan casing is fixed on the second fixed bracket, and a fan rotor is inside the fan casing. The fan casing, the air intake casing and the fan rotor together constitute a fan component unit body, so as to simulate the influence of a fan blade being hit by a bird on the fan casing and the component unit body.

[0013] Preferably, a front bracket is arranged in front of the air intake casing, and a rear fulcrum is arranged behind the fan casing, and both the front fulcrum and the rear fulcrum are rotatably matched with the fan rotor.

[0014] Preferably, a coupling and a double fulcrum of the device are also provided behind the rear fulcrum, the coupling is fixedly connected to the end of the fan rotor, and the rear end of the coupling is connected to the double fulcrum of the device.

[0015] Preferably, the air intake casing and the fan casing are also provided with a positioning system, and the positioning system includes an air intake fixing plate, a fan fixing plate, a vertical bracket assembly, an upper bracket assembly and a lower bracket assembly; the air intake fixing plate is fixedly connected to the air intake casing, an air intake support plate is provided on the inner side of the air intake fixing plate, and the fan fixing plate is fixedly connected to the fan casing for further supporting the air intake casing and the fan casing respectively, the vertical bracket assembly is coaxially arranged with the fan rotor, and the upper bracket assembly and the lower bracket assembly are arranged correspondingly up and down.

[0016] Preferably, a front aluminum pad is arranged between the air intake fixing plate and the fan rotor, and a rear aluminum pad is arranged between the vertical bracket assembly and the fan rotor.

[0017] Preferably, the corresponding test steps include:

[0018] Process 1: The bird is launched through the air gun and the bullet and shell are separated by the ejector at the end of the air gun. At this time, the initial launch speed V1 of the bird can be measured;

[0019] Process 2: The bird hits the first ejection plate, simulating the first impact of a real bird on the inner wall of the aircraft's air inlet. The inner wall of the air inlet forms an angle with the aircraft's flight direction. The angle can be adjusted by adjusting the placement angle of the ejection plate A. After the first impact, the bird continues to move forward along the tangent direction of the ejection plate A, and the speed decays to V2.

[0020] Process 3: The bird hits the second ejection plate, simulating a real bird flying through the S-bend inlet and hitting another inner wall, which is parallel to the engine axis. After the second impact, the bird enters the fan unit along the engine axis, and the bird speed decays to V3.

[0021] Process 4: The bird body passes through the C-shaped hole reserved in the intake casing and hits the intake support plate. At this time, the bird body is split into different parts after being hit by the intake support plate, and the speed of the main part is attenuated to V4;

[0022] Process 5: The main part of the bird's body hits the rotating fan rotor at a speed of V4, causing the fan blades to curl or even fall off. The fallen blades hit the fan case along the tangential direction of the fan rotor to test the containment of the fan case.

[0023] The bird strike test device of the present application simulates a real engine, by setting a first ejection plate, a second ejection plate, a first fixed bracket that simulates the impact of a fan blade hit by a bird on a fan case and a component unit, an air intake case and a second fixed bracket, to simulate the ejection impact of the air intake duct on the bird and the process of the bird hitting the air intake support plate. In the case of limited space, it can effectively simulate the changes in the bird's motion trajectory and the cutting and deceleration effect of the air intake support plate on the bird, thereby achieving an accurate assessment of the engine's ability to withstand bird strikes. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solution provided by the present application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present application.

[0025] Figure 1 It is a schematic diagram of an existing bird strike test device;

[0026] Figure 2 This is a schematic diagram of the overall structure of this application;

[0027] Figure 3 This is a schematic diagram of the positioning system structure for this application;

[0028] Figure 4 This is a schematic diagram of the structure of the bracket assembly for this application;

[0029] Figure 5 This is a schematic diagram of the fan fixing plate structure of this application;

[0030] Figure 6 This is a schematic diagram of the structure of the air intake fixing plate of this application;

[0031] Figure 7 Front view of the bird strike test device for this application.

[0032] 1. Gas gun; 2. First ejection plate; 3. Second ejection plate; 4. Rear support plate; 5. First fixed bracket; 6. Intake casing; 7. Fan casing; 8. Second fixed bracket; 9. Fan rotor; 10. Front fulcrum; 11. Coupling; 12. Double fulcrum of equipment; 13. Front aluminum pad; 14. Intake fixing plate; 15. First bolt; 16. Upper bracket assembly; 17. Fan fixing plate; 18. Second bolt; 19. Vertical bracket assembly; 20. Screw; 21. Rear aluminum pad; 22. Lower bracket assembly; 23. Intake support plate. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] A bird strike test device that simulates a real engine, such as Figure 2 , including an air gun 1, a first ejection plate 2, a second ejection plate 3, a first fixed bracket 5, an air intake casing 6, and a second fixed bracket 8. The outlet of the air gun 1 is arranged corresponding to the first ejection plate 2 and the second ejection plate 3; the first ejection plate 2 and the second ejection plate 3 are arranged front and back, and the first fixed bracket 5 and the air intake casing 6 are both located behind the second ejection plate 3, which are used to simulate the aircraft air intake duct; and the air intake casing 6 is installed on the first fixed bracket 5, which is used to simulate the process of a bird hitting the air intake support plate 23; a fan casing 7 is fixed on the second fixed bracket 8, and a fan rotor 9 is inside the fan casing 7. The fan casing 7, the air intake casing 6, and the fan rotor 9 together form a fan component unit body, which is used to simulate the impact of the fan blades on the fan casing 7 and the component unit body after being hit by a bird. The bird hitting the fan blades is likely to cause the blades to fall off and hit the fan casing 7, and the inclusiveness requirements of the fan casing 7 are tested. Because the double-pivot structure is different from the real engine, the coaxiality requirements between the fan casing 7 and the fan rotor 9 need to be guaranteed.

[0035] Since the length of the actual S-curve air inlet of an aircraft is about 8 to 10 meters and the manufacturing cost is expensive, it is impossible to use the actual air inlet for bird strike tests under test conditions. Therefore, two ejection plates with material, thickness and surface roughness as consistent as possible with the actual air inlet are set up in a limited space to simulate the ejection and impact effect of the S-curve air inlet on the bird. The bird's trajectory changes significantly and it eventually enters the fan component along the axial direction of the engine.

[0036] After passing through the air intake duct, the bird body hits the air intake support plate 23. Firstly, it is tested whether the strength of the air intake support plate 23 can meet the structural integrity requirements after the bird body hits it. Secondly, the air intake support plate 23 has a cutting and decelerating effect on the bird body. After passing through the air intake support plate 23, the bird body has a significant reduction in mass and speed.

[0037] Preferably, a front bracket is provided in front of the air intake casing 6 and a rear fulcrum is provided behind the fan casing 7 . Both the front fulcrum 10 and the rear fulcrum are rotatably matched with the fan rotor 9 to support the fan rotor 9 .

[0038] A coupling 11 and a device double pivot 12 are also provided behind the rear pivot. The coupling is fixedly connected to the end of the fan rotor 9. The rear end of the coupling 11 is connected to the device double pivot 12 for further fixing the fan rotor 9.

[0039] Preferably, it is necessary to consider the installation and fixation of the air intake casing 6 and the fan casing 7 components, as well as the coaxiality of the casing components and the fan rotor 9 components, so the corresponding air intake casing 6 and the fan casing 7 are also provided with a positioning system, such as Figure 3 The positioning system includes an air intake fixing plate 14, a fan fixing plate 17, a vertical bracket assembly 19, an upper bracket assembly 16 and a lower bracket assembly 22. The air intake fixing plate 14 is fixedly connected to the air intake casing 6, an air intake support plate 23 is provided inside the air intake fixing plate 14, the fan fixing plate 17 is fixedly connected to the fan casing 7, and is used to further support the air intake casing 6 and the fan casing 7 respectively. The vertical bracket assembly 19 is coaxially arranged with the fan rotor 9, and the vertical bracket assembly 19 is connected to the fan fixing plate 17 by a second bolt 18. The upper bracket assembly 16 and the lower bracket assembly 22 are arranged correspondingly up and down, and both support and fix the air intake fixing plate 14 and the fan fixing plate 17.

[0040] Preferably, the air intake fixing plate 14 is connected to the upper bracket assembly 16 and the lower bracket assembly 22 by bolts.

[0041] Preferably, due to the limited space in the vacuum chamber, the fan component unit body must be assembled outside the vacuum chamber, so a front aluminum pad 13 is set between the air intake fixed plate 14 and the fan rotor 9, and a rear aluminum pad 21 is set between the vertical bracket assembly 19 and the fan rotor 9. After adjusting the coaxiality of the air intake casing 6, the fan casing 7 and the fan rotor 9, the unit body is installed and fixed after entering the vacuum chamber as a whole and fixing it with the front and rear fulcrums and the cabin inner rail. After the fulcrum and the ground rail are bolted, the front aluminum pad 13 and the rear aluminum pad 21 are removed to complete the installation of the test device.

[0042] Preferably, the rear end aluminum pad 21 is connected to the vertical support assembly 19 via screws 20 .

[0043] Unlike the real structure of the engine, the fulcrum bearing structure of the casing assembly and the fan rotor 9 assembly cannot be simulated under the test conditions. Therefore, it is necessary to ensure that the casing assembly has sufficient rigid support to prevent bird strikes from causing additional impact on the casing structure. A vertical bracket assembly 19 is designed at the rear end of the fan rotor 9. Figure 4 The bottom is connected and fixed by bolts to the inner rail of the vacuum chamber, and the mounting edge is connected by bolts to the fan fixing plate 17 to support the fan casing 7 assembly, such as Figure 5 shown.

[0044] Since it is difficult to place a bracket at the front end of the fan rotor 9 due to space limitations, an upper bracket assembly 16 and a lower bracket assembly 22 are designed. The lower bracket assembly 22 is fixed to the inner rail of the cabin by anchor bolts, and the upper bracket assembly 16 is fixed to the lower bracket assembly 22 by a split method through a flange edge. The front end is then fixed to the intake casing 6 through an intake fixing plate 14, and a C-shaped hole is opened on one side of the intake fixing plate 14 for the bird to pass through, such as Figure 6 The front view of the test device is shown in Figure 7 shown.

[0045] By providing a first ejection plate 2, a second ejection plate 3, a first fixed bracket for simulating the effect of a fan blade being hit by a bird on a fan casing 7 and a component unit, an air intake casing 6 and a second fixed bracket 8, the ejection impact of the air intake duct on the bird and the impact of the bird on the air intake support plate 23 are simulated. In the case of limited space, the changes in the motion trajectory of the bird and the cutting and deceleration effect of the air intake support plate 23 on the bird are effectively simulated, thereby achieving an accurate assessment of the engine's ability to withstand bird impacts.

[0046] As a specific implementation method, a bird strike test step simulating a real engine is also included, including: process 1: a bird body is launched through the gas gun 1 and the bullet and the shell are separated by the ejector at the end of the gas gun 1, at which time the initial launch speed V1 of the bird body can be measured;

[0047] Process 2: The bird hits the first ejection plate 2, simulating the first impact of a real bird on the inner wall of the aircraft's air inlet. The inner wall of the air inlet forms an angle with the aircraft's flight direction. The angle can be adjusted by adjusting the placement angle of the ejection plate A. After the first impact, the bird continues to move forward along the tangent direction of the ejection plate A, and the speed decays to V2.

[0048] Process 3: The bird hits the second ejection plate 3, simulating a real bird flying through the S-bend inlet and hitting another inner wall, which is parallel to the engine axis. After the second impact, the bird enters the fan unit component along the engine axis, and the bird speed decays to V3.

[0049] Process 4: The bird body passes through the C-shaped hole reserved in the air intake casing 6 and hits the air intake support plate 23. At this time, the bird body is divided into different parts after being hit by the air intake support plate 23, and the speed of the main part is attenuated to V4;

[0050] Process 5: The main part of the bird's body hits the rotating fan rotor 9 at a speed of V4, causing the fan blades to curl or even fall off. The fallen blades hit the fan casing 7 along the tangential direction of the fan rotor 9 to test the containment of the fan casing 7.

[0051] From the above analysis, it can be seen that the invented bird strike test device effectively simulates the impact of the air intake on the bird strike, the impact of the air intake casing and the air intake support plate on the bird strike, and the impact of the bird strike on the fan blades under the test conditions. The bird strike resistance of the real fan blades has a more accurate assessment of the bird mass and bird speed, which greatly saves the test cost compared to the whole machine bird swallowing test.

[0052] Finally, it should be noted that: the drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0053] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A bird strike test device simulating a real engine, characterized in that: The invention comprises an air gun (1), a first ejection plate (2), a second ejection plate (3), a first fixed bracket (5), an air intake casing (6) and a second fixed bracket (8); the outlet of the air gun (1) is arranged corresponding to the first ejection plate (2) and the second ejection plate (3); the first ejection plate (2) and the second ejection plate (3) are arranged front and rear, the first fixed bracket (5) and the air intake casing (6) are both located behind the second ejection plate (3) and are used to simulate the air intake duct of an aircraft; and the air intake casing (6) is installed on the first fixed bracket (5) and is used to simulate the process of a bird body hitting an air intake support plate (23); a fan casing (7) is fixed on the second fixed bracket (8), a fan rotor (9) is arranged inside the fan casing (7), and the fan casing (7), the air intake casing (6) and the fan rotor (9) together form a fan component unit body, which is used to simulate the influence of a fan blade being hit by a bird on the fan casing (7) and the component unit body.

2. The bird strike test device for simulating a real engine as claimed in claim 1, characterized in that: A front bracket is arranged in front of the air intake casing (6), and a rear fulcrum is arranged behind the fan casing (7). Both the front fulcrum (10) and the rear fulcrum are rotatably matched with the fan rotor (9).

3. The bird strike test device for simulating a real engine as claimed in claim 1, characterized in that: A coupling (11) and a double equipment pivot (12) are also arranged behind the rear pivot. The coupling is fixedly connected to the end of the fan rotor (9), and the rear end of the coupling (11) is connected to the double equipment pivot (12).

4. The bird strike test device for simulating a real engine as claimed in claim 1, characterized in that: The air intake casing (6) and the fan casing (7) are also provided with a positioning system, and the positioning system includes an air intake fixing plate (14), a fan fixing plate (17), a vertical bracket assembly (19), an upper bracket assembly (16) and a lower bracket assembly (22); the air intake fixing plate (14) is fixedly connected to the air intake casing (6), an air intake support plate (23) is provided on the inner side of the air intake fixing plate (14), and the fan fixing plate (17) is fixedly connected to the fan casing (7) for further supporting the air intake casing (6) and the fan casing (7) respectively; the vertical bracket assembly (19) is coaxially arranged with the fan rotor (9), and the upper bracket assembly (16) and the lower bracket assembly (22) are arranged correspondingly up and down.

5. The bird strike test device for simulating a real engine as claimed in claim 4, characterized in that: A front aluminum pad (13) is arranged between the air intake fixed plate (14) and the fan rotor (9), and a rear aluminum pad (21) is arranged between the vertical support assembly (19) and the fan rotor (9).

6. The bird strike test device for simulating a real engine as claimed in claim 1, characterized in that: The corresponding test steps include: Process 1: The bird body is launched through the gas gun (1) and the bullet and the shell are separated by the ejector at the end of the gas gun (1). At this time, the initial launch speed V1 of the bird body can be measured; Process 2: The bird body hits the first ejection plate (2), simulating the first impact of a real bird body on the inner wall of the aircraft air inlet. The inner wall of the air inlet forms an angle with respect to the flight direction of the aircraft. The angle can be adjusted and simulated by adjusting the placement angle of the ejection plate A. After the first impact, the bird body continues to move forward along the tangent direction of the ejection plate A, and the speed decays to V2; Process 3: The bird body hits the second ejection plate (3), simulating a real bird body continuing to fly through the S-bend inlet and hitting another inner wall, which is parallel to the engine axis. After the second impact, the bird body enters the fan unit component along the engine axis. At this time, the bird body speed decays to V3; Process 4: The bird body passes through the C-shaped hole reserved in the air intake casing (6) and hits the air intake support plate (23). At this time, the bird body is split into different parts after being hit by the air intake support plate (23), and the speed of the main part is attenuated to V4; Process 5: The main part of the bird's body hits the rotating fan rotor (9) at a speed of V4, causing the fan blades to curl or even fall off. The fallen blades hit the fan casing (7) along the tangential direction of the fan rotor (9) to test the containment of the fan casing (7).

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