A method for determining the swallowing capacity of an aeroengine

Abstract

This application provides a method for determining the bird-swallowing capability of an aero-engine, belonging to the field of aero-engine testing. The method includes: evaluating the bird strike resistance of blades using strength simulation, correcting it with component test results to obtain the blade's bird strike resistance characteristics; evaluating the aerodynamic impact of damaged blades through aerodynamic modeling, correcting it with blade-mounted testing to obtain the aerodynamic impact characteristics of damaged blades on the engine; determining the quantitative relationship between bird-swallowing parameters and blade damage based on test and simulation results; determining the strength and aerodynamic boundaries of the aero-engine's bird-swallowing capability; determining the engine's bird-swallowing capability based on the engine's bird-swallowing strength and aerodynamic boundaries, combined with bird-swallowing standards; and improving the bird-swallowing capability of an engine with determined bird-swallowing capability through targeted design improvements.

Description

Technical Field

[0001] This application belongs to the field of aero-engine testing, and specifically relates to a method for determining the bird-swallowing capability of an aero-engine. Background Technology

[0002] Aircraft engines need to undergo bird-swallowing tests, which involve swallowing a certain number and weight of birds according to specific standards to assess the engine's safety when encountering birds in the air. Currently, the bird-swallowing capability of aircraft engines can be verified through preliminary stationary blade bird strike tests, rotating component bird strike tests, and finally, whole-engine bird-swallowing tests.

[0003] Current bird-swallowing component and engine tests primarily aim to verify whether an engine can pass bird-swallowing tests. However, due to high testing costs, long cycles, and a limited number of tests, these tests do not provide a comprehensive understanding of the engine's bird-swallowing capabilities and cannot determine its maximum or minimum bird-swallowing capacity. Furthermore, by the time an engine is ready for testing, its design phase is nearing completion. If the bird-swallowing capability does not meet requirements, design improvements at this stage are costly and difficult. Therefore, a comprehensive verification method for understanding an engine's bird-swallowing capability is needed, which can also guide the engine's bird-strike resistant design. Summary of the Invention

[0004] To address the aforementioned problems, this application provides a method for determining the bird-swallowing capability of an aircraft engine, comprising:

[0005] Step S1: Determine the test parameters for the bird-swallowing test of the test specimen based on the given bird-swallowing test assessment standards;

[0006] Step S2: Based on the test parameters, perform blade bird strike intensity simulation calculations on the test specimen to obtain a damage simulation model;

[0007] Step S3: Perform a component rotation test on the test piece, and use the results of the component rotation test to verify the damage simulation model to obtain a high-precision damage simulation model;

[0008] Step S4: Based on the high-precision damage simulation model, perform aerodynamic simulation evaluation to obtain a bird strike damage aerodynamic loss evaluation model;

[0009] Step S5: Conduct a damaged blade clipping test on the test piece, and verify the results of the damaged blade clipping test against the bird strike damage aerodynamic loss assessment model to obtain a high-precision bird strike damage aerodynamic loss assessment model.

[0010] Step S6: Adjust the test parameters to obtain multiple high-precision damage simulation models of different weight bird impacts at different positions of the test blade, and determine the strength boundary of the aero-engine's bird-swallowing capability; by adjusting the input parameters of the high-precision bird strike damage aerodynamic loss assessment model, obtain the parameters of thrust loss and aerodynamic loss caused by different weight bird impacts at different positions of the test blade, and determine the aerodynamic boundary of the aero-engine's bird-swallowing capability.

[0011] Step S7: Determine the engine's bird-swallowing capability based on the strength boundary and aerodynamic boundary of the engine's bird-swallowing capability, combined with the standards for the bird-swallowing test.

[0012] Preferably, the test parameters described in step S1 include: engine status parameters, bird speed parameters, and fan speed parameters.

[0013] Preferably, step S1 also determines the evaluation criteria for passing the test, the procedures and time executed by the engine after swallowing the bird, the continuous operating time of the test state, and the thrust loss.

[0014] Preferably, the result of the component rotation test is the damage mode of the actual damaged blade of the test piece, and the damage mode includes cracking, deformation and chipping of the test piece.

[0015] Preferably, the simulated bird used in the component rotation test is the same as the simulated bird used in the simulation calculation of the blade bird strike intensity.

[0016] Preferably, a method for using the high-precision damage simulation model is as follows: adjust the test parameters to obtain multiple damage simulation models of different weight bird impacts at different positions of the test blade, and determine the strength boundary of the aero-engine's bird-swallowing capability.

[0017] The advantages of this application include:

[0018] 1. Determine the bird-eating capability of aircraft engines;

[0019] 2. The method for determining bird-swallowing ability is low-cost, short-cycle, and low-risk;

[0020] 3. The method for determining bird-swallowing capability is generalizable and not limited to a specific engine;

[0021] 4. The method for determining bird-swallowing capability can provide reverse guidance for the design of bird-strike resistant engines. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the method for determining a bird-swallowing ability. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0024] To determine the bird-swallowing capability of an engine, it is first necessary to define the bird-swallowing capability of an aero-engine.

[0025] Bird ingestion tests on aircraft engines generally determine key test parameters such as the weight, number, location, bird speed, and engine speed of the ingested bird based on the engine's structure and performance parameters. Taking airworthiness standards as an example, the standard first specifies the test bird weight, then selects the number of birds to be ingested based on the engine's inlet diameter, next considers the internal bird ingestion capability assessment, combines the strength analysis results of the first-stage rotor blades to determine the bird ingestion location distribution, and finally selects the engine's maximum takeoff state as the test state for bird ingestion. The bird speed is determined by the engine's flight speed under specific conditions. According to the standard requirements, the passing criteria for engine bird ingestion capability tests mainly include two aspects: continuous operation and thrust damage. That is, after bird ingestion, the engine must continue to operate for a specific time under given engine conditions, provided that the thrust loss is not less than the required value.

[0026] As can be seen from the bird swallowing test standards, apart from the bird weight and number, all other test parameters are determined by the engine's structure and performance parameters. Since the number of birds swallowed is related to the swallowing location, changing the number requires simultaneously adjusting the swallowing location. To clearly compare and analyze bird swallowing capability, the bird's weight is chosen as the balancing parameter for the engine's bird swallowing capability; that is, the engine's bird swallowing capability is defined as the weight of a bird that the engine can swallow, assuming all parameters in the bird swallowing test remain constant according to relevant standards. A flowchart of the method for determining bird swallowing capability is shown below. Figure 1

[0027] The specific tasks in the flowchart are explained below:

[0028] 1) Determine the standard for swallowing birds

[0029] The aircraft engine designer and the user jointly determine the standard basis for bird swallowing test assessment, such as the civil engine airworthiness standard CCAR 33 or other standards approved by the user.

[0030] 2) Determine the experimental parameters

[0031] Based on the bird swallowing standard, determine the test parameters such as engine status, bird speed, and fan speed for the bird swallowing test; determine the evaluation criteria for passing the test; determine the procedures and time to be executed by the engine after bird swallowing; determine the continuous running time of the test state; and determine the thrust loss requirements.

[0032] 3) Strength simulation

[0033] Following a validated simulation method for bird strike damage intensity of fan blades, simulation calculations were performed using defined experimental parameters. To ensure that the simulated bird parameters were identical to those used in the component rotation test, the simulated bird was modeled based on the material and strength parameters of the gelatin bird used in the component rotation test. Through component rotation tests, realistic blade damage modes, including cracking, deformation, chipping, and damage dimensions, were obtained. The damage simulation model was then validated to obtain a high-precision strength simulation model. By adjusting the simulation test parameters, various damage simulation models of different blade locations subjected to bird strikes of varying weights were quickly obtained.

[0034] The component rotation test involved conducting a bird strike test using the validated method for rotating fan rotor blades, with the required test parameters. The simulated bird was prepared using a standardized gelatin bird preparation method to ensure consistent bird parameters. Specific test conditions were selected based on the needs of strength simulation verification and whole-machine blade mounting tests to obtain realistically damaged blade data.

[0035] 4) Strength Criteria

[0036] Based on the strength simulation model and component test results, the maximum bird weight that different positions of the fan blades can withstand from a bird strike is determined, which is the strength criterion for the bird-swallowing capability of the aero-engine.

[0037] 5) Aerodynamic simulation

[0038] Based on the damaged blade model parameters obtained from strength simulation, an aerodynamic simulation model is used to assess the aerodynamic impact of bird strike damage. The aerodynamic simulation assessment results are then verified against the results of whole-engine blade-mounted tests, resulting in a high-precision aerodynamic loss assessment model for bird strike damage. By adjusting the aerodynamic model parameters, aerodynamic loss parameters, such as thrust loss, caused by impacts of different bird weights at different locations on the blade can be quickly obtained.

[0039] Among them, the damaged leaf clipping test:

[0040] Following a low-risk, high-reliability test method for damaged blades, a whole-engine blade-mounted test was conducted with defined test parameters. The test used real damaged blades obtained from component rotation tests. To minimize test risk, pre-test balancing of the fan-stage blades was permitted, but disruption of the damage arrangement within each group of damaged blades was not allowed. After the aerodynamic simulation evaluation model was verified during the whole-engine blade-mounted test, the engine was continuously operated for a specific time under specific engine conditions according to standard requirements. Following the test, the damage to the engine core and various support points was inspected, and the impact of the damaged fan blades on the overall engine stability was assessed.

[0041] 6) Aerodynamic Criteria

[0042] Based on the maximum aerodynamic loss requirements of the bird swallowing standard, and according to the aerodynamic simulation analysis and whole-engine hanging plate test results, the whole-engine bird swallowing test parameters, such as the maximum bird weight and number at different positions that the aero-engine can withstand, are determined. These parameters are the aerodynamic criteria for the bird swallowing capability of the aero-engine.

[0043] 7) Bird-swallowing ability judgment

[0044] Based on the bird swallowing standard requirements, and combined with the bird weight obtained from the strength criteria and aerodynamic criteria, the maximum bird weight that the fan blades can withstand at different positions is determined. The maximum number of birds that an aero-engine can withstand at a specific position and with a specific bird weight is the bird swallowing capacity of the aero-engine.

[0045] 8) Guiding engine design

[0046] After determining the bird-swallowing capability of an engine according to the bird-swallowing capability determination method described in this patent, if the capability does not meet the standard requirements, weak links can be identified from the determination process and adaptive improvements can be made. For example, if the first-stage fan blades cannot withstand the bird impact weight required by the standard, the bird-swallowing capability of the engine can be improved by enhancing the bird strike resistance of the first-stage fan blades.

[0047] In summary, one implementation method of this application is as follows:

[0048] Step S1: Determine the test parameters for the bird swallowing test of the test specimen based on the given bird swallowing test assessment standards; including: engine condition parameters, bird speed parameters, and fan speed parameters. Such as the civil engine airworthiness standard CCAR 33 or other standards approved by the user.

[0049] Step S2: Based on the test parameters, perform a bird strike intensity simulation calculation on the test specimen to obtain a damage simulation model; the parameters include: engine status, bird speed, and fan speed during the bird ingestion test; the evaluation criteria for passing the test; the program and time executed by the engine after the bird ingestion; the continuous running time of the test state; thrust loss requirements, etc.; the damage simulation model is a three-dimensional model of the damaged blade; the three-dimensional model can form different damage effects according to the input bird weight and impact position.

[0050] Step S3: Perform a component rotation test on the test piece, and verify the damage simulation model using the results of the component rotation test to obtain a high-precision damage simulation model; verify the damage simulation model through actual testing; obtain a high-precision damage simulation model.

[0051] Step S4: Based on the high-precision damage simulation model, perform aerodynamic simulation evaluation to obtain a bird strike damage aerodynamic loss evaluation model; the aerodynamic simulation evaluation involves inputting the relevant aerodynamic simulation parameters into the corresponding software to obtain the performance parameters of the high-precision damage simulation model.

[0052] Step S5: Conduct a damaged blade clipping test on the test piece, and verify the results of the damaged blade clipping test against the bird strike damage aerodynamic loss assessment model to obtain a high-precision bird strike damage aerodynamic loss assessment model.

[0053] Step S6: Adjust the test parameters to obtain multiple high-precision damage simulation models of different weight bird impacts at different positions of the test blade, and determine the strength boundary of the aero-engine's bird-swallowing capability; by adjusting the input parameters of the high-precision bird strike damage aerodynamic loss assessment model, obtain the parameters of thrust loss and aerodynamic loss caused by different weight bird impacts at different positions of the test blade, and determine the aerodynamic boundary of the aero-engine's bird-swallowing capability.

[0054] Step S7: Based on the strength boundary and aerodynamic boundary of the engine bird ingestion test, and in conjunction with the standards for bird ingestion test assessment, determine the engine's bird ingestion capability. The strength boundary is the physical bearing boundary of the blades after a bird strike, and the aerodynamic boundary is the performance boundary. The combination of the two can be used to evaluate the engine's ability to withstand the weight of a bird, i.e., its bird ingestion capability.

[0055] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for determining the bird-eating capability of an aero-engine, characterized in that, include: Step S1: Determine the test parameters for the bird-swallowing test of the test specimen based on the given standards for bird-swallowing test assessment; Step S2: Based on the test parameters, perform blade bird strike intensity simulation calculations on the test specimen to obtain a damage simulation model; Step S3: Perform a component rotation test on the test piece, and use the results of the component rotation test to verify the damage simulation model to obtain a high-precision damage simulation model; Step S4: Based on the high-precision damage simulation model, perform aerodynamic simulation evaluation to obtain a bird strike damage aerodynamic loss evaluation model; Step S5: Conduct a damaged blade clipping test on the test piece, and verify the results of the damaged blade clipping test against the bird strike damage aerodynamic loss assessment model to obtain a high-precision bird strike damage aerodynamic loss assessment model. Step S6: Adjust the test parameters to obtain multiple high-precision damage simulation models of different weight bird impacts at different positions of the test blade, and determine the strength boundary of the aero-engine's bird-swallowing capability; by adjusting the input parameters of the high-precision bird strike damage aerodynamic loss assessment model, obtain the parameters of thrust loss and aerodynamic loss caused by different weight bird impacts at different positions of the test blade, and determine the aerodynamic boundary of the aero-engine's bird-swallowing capability. Step S7: Determine the engine's bird-swallowing capability based on the strength boundary and aerodynamic boundary of the engine's bird-swallowing capability, combined with the standards for the bird-swallowing test.

2. The method for determining the bird-eating capability of an aero-engine as described in claim 1, characterized in that, The test parameters mentioned in step S1 include: engine status parameters, bird speed parameters, and fan speed parameters.

3. The method for determining the bird-eating capability of an aero-engine as described in claim 1, characterized in that, Step S1 also determines the evaluation criteria for passing the test, the procedures and time executed by the engine after swallowing the bird, the duration of continuous operation in the test state, and the thrust loss.

4. The method for determining the bird-eating capability of an aero-engine as described in claim 1, characterized in that, The results of the component rotation test are the damage modes of the actual damaged blades of the test piece, including cracking, deformation, and chipping of the test piece.

5. The method for determining the bird-eating capability of an aero-engine as described in claim 1, characterized in that, The simulated bird used in the component rotation test is the same as the simulated bird used in the simulation calculation of the blade bird strike intensity.

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