Rocket engine mechanical environment adaptability analysis method
By utilizing engine test data and previous mechanical test data, combined with finite element simulation, the problems of large-scale and long-cycle tests in engine mechanical environment adaptability analysis were solved, and efficient mechanical environment adaptability verification was achieved.
Patent Information
- Application Number
- CN202511069728.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-31
- Publication Date
- 2025-11-28
AI Technical Summary
Existing technologies suffer from problems such as large-scale and long-term testing in engine mechanical environment adaptability analysis. In particular, when a single engine is used with multiple types of rockets or an improved engine is used with a rocket, it is difficult to effectively cover the differences in mechanical environment proposed by new rockets.
By utilizing engine test data and previous mechanical test data, combined with finite element simulation, and through the transfer functions of the engine's major components, response prediction and simulation analysis or supplementary tests are conducted to verify the engine's mechanical environmental adaptability.
The scale of mechanical testing was reduced, development costs were decreased, and the efficiency of engine mechanical environment adaptability verification was improved.
Smart Images
Figure CN121031027A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of rocket engine technology, and more specifically to a method for analyzing the mechanical environment adaptability of rocket engines. Background Technology
[0002] With the high-density launch of rockets and the development of new and improved rockets, the demand for engine commercialization is increasing. This has led to situations where a single engine is used in multiple types of rockets, or where an improved version of a particular engine is used in a rocket. Before an engine is delivered for flight, a mechanical environment adaptability analysis must be conducted to verify its mechanical environmental adaptability.
[0003] The mechanical environment adaptability of an engine generally includes two parts: one is its adaptability to the mechanical environment of the rocket, which is usually verified through mechanical environment tests; the other is its adaptability to the engine's own working environment. For a single engine, this is usually verified through engine testing. For multiple parallel engines, the swaying part of a single engine can be verified through engine testing, while the shared parts are mostly verified through vibration tests.
[0004] When an engine is used with multiple types of rockets, the mechanical environment proposed by different rockets may vary due to differences in launch sites, rocket configurations, thrust, etc. If the previous mechanical environment test scale of the engine cannot cover the mechanical environment proposed by the new rocket, relevant mechanical tests are generally carried out again for verification.
[0005] For rockets equipped with a certain improved engine, due to slight modifications in engine layout, the engine's mechanical environmental adaptability is typically verified through various mechanical tests. Considering the difficulty, large scale, and long cycle of engine vibration testing, a method for analyzing the mechanical environmental adaptability of rocket engines is urgently needed. Summary of the Invention
[0006] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a method for analyzing the mechanical environment adaptability of rocket engines. By utilizing and mining engine test data and previous engine mechanical test data, combined with finite element simulation, the mechanical environment adaptability of the engine can be directly verified or the scale of mechanical tests can be reduced.
[0007] The technical solution of this invention is: a method for analyzing the mechanical environment adaptability of a rocket engine, comprising:
[0008] 1) Compare the old and new mechanical environments of the engine to determine whether the original mechanical environment covers the new mechanical environment; if it covers, it proves that the engine can adapt to the new mechanical environment; if it does not cover, proceed to step 2).
[0009] 2) Based on previous engine mechanical test data, obtain the transfer functions of each major engine assembly; refer to previous engine mechanical test data, and take the mechanical test control input or the connection between the engine frame and the rocket body as the reference, calculate the transfer function G(f) = Y(f) / R(f) of each major engine assembly to the reference position, where Y(f) is the response curve of each major engine assembly and R(f) is the control curve.
[0010] 3) By using the transfer functions of each major engine component to the reference position and combining them with the new mechanical environment conditions, the predicted responses of each major engine component are obtained;
[0011] 4) Compare the estimated responses of the major engine components with the engine test vibration data, and use simulation analysis or conduct supplementary tests to determine the engine's mechanical environmental adaptability.
[0012] By conducting sinusoidal scanning tests, vibration tests, noise tests, and impact tests, it can be determined whether the original mechanical environment covers the new mechanical environment.
[0013] The determination of whether the original mechanical environment covers the new mechanical environment by conducting sinusoidal scanning tests, vibration tests, noise tests, and impact tests specifically includes:
[0014] For a sinusoidal scanning test, if A1(f)≥A2(f) is satisfied, it means that the original mechanical environment covers the new mechanical environment; where A1(f) is the acceleration amplitude corresponding to frequency f under the original mechanical environment condition, and A2(f) is the acceleration amplitude corresponding to frequency f under the new mechanical environment condition.
[0015] For vibration tests, if psd1(f)≥psd2(f) is satisfied, it means that the original mechanical environment covers the new mechanical environment; where psd1(f) is the power spectral density corresponding to frequency f under the original mechanical environment conditions, and psd2(f) is the power spectral density corresponding to frequency f under the new mechanical environment conditions.
[0016] For noise tests, if P1(f)≥P2(f), it means that the original mechanical environment covers the new mechanical environment; where P1(f) is the sound pressure amplitude corresponding to frequency f under the original mechanical environment conditions, and P2(f) is the sound pressure amplitude corresponding to frequency f under the new mechanical environment conditions.
[0017] For impact tests, if SRS1(f)≥SRS2(f), it means that the original mechanical environment covers the new mechanical environment; where SRS1(f) is the acceleration response value corresponding to frequency f under the original mechanical environment conditions, and SRS2(f) is the acceleration response value corresponding to frequency f under the new mechanical environment conditions.
[0018] For the same type of engine, if the original mechanical environment covers the new mechanical environment, it proves that the engine can adapt to the new mechanical environment; if it does not cover the new mechanical environment, proceed to step 2). For an improved engine, if the original mechanical environment covers the new mechanical environment, it proves that the unchanged part of the engine structure can adapt to the new mechanical environment, and the changed part proceeds to step 2); if it does not cover the new mechanical environment, proceed directly to step 2).
[0019] The term "same type of engine" refers to an engine with the same structure that is used in multiple types of rockets; the term "improved engine" refers to an engine with the same main power transmission path, the same overall engine mode and natural frequency as the original engine, but with other structural changes.
[0020] The main components include a frame, a constant level seat, a thrust chamber, a turbopump, a nozzle, and valves; the mechanical tests include modal tests, sinusoidal sweep tests, and random vibration tests.
[0021] The method of using the transfer function of each major engine assembly to the reference position and combining it with the new mechanical environment conditions to obtain the estimated response of each major engine assembly includes: for the obtained transfer function G(f), combining it with the new mechanical environment conditions R'(f), to obtain the response of each major engine assembly under the new mechanical environment conditions Y'(f) = G(f) × R'(f).
[0022] The process of comparing the estimated responses of each major engine component with engine test vibration data, and using simulation analysis or supplementary tests to determine the engine's adaptability to the mechanical environment includes: comparing the obtained responses Y'(f) of each major engine component with the responses A(f) at the same location in the same frequency band during engine testing; if Y'(f) ≤ A(f), the engine can adapt to the new mechanical environment; if Y'(f) > A(f), then using Y'(f) as the input load, performing local finite element simulation calculations, and judging its adaptability to the mechanical environment through finite element analysis; or conducting supplementary tests to verify the adaptability to the mechanical environment.
[0023] The simulation analysis described above is suitable for situations where there are relatively few components that do not cover the new mechanical environment. The specific process is as follows: Finite element modeling is used, with the actual installation state of the component on the engine as the boundary. For a component that is installed as a whole on a major assembly, the response Y'(f) at the major assembly is used as the input load. For a component that is installed at one end on a major assembly and at the other end on another major assembly, the larger response Y'(f) of the two is used as the input load. Dynamic strength calculation is performed to obtain the dynamic stress of the component. If the dynamic stress is less than the yield strength of the material, it can adapt to the new mechanical environment. Otherwise, the design is improved. The simulation is performed again after the design improvement until it adapts to the new mechanical environment.
[0024] The supplementary test is applicable when there are relatively many components that do not cover the new mechanical environment. The specific process is as follows: According to the actual installation state on the engine, the components that do not cover the new mechanical environment and their mounting bases are assembled into a whole. This whole is used as the test object. According to the sequence of the engine's main force transmission path, the response Y'(f) of the main assembly corresponding to the first force transmission path of the test object is used as the input load to carry out mechanical tests. After the test, the test object is inspected. If the test object's function and performance are intact, it indicates that the engine can adapt to the new mechanical environment. Otherwise, design improvements are made. After the design improvements, supplementary tests are carried out again until it adapts to the new mechanical environment.
[0025] The advantages of this invention compared to the prior art are:
[0026] This invention utilizes the engine's own transmission characteristics and, through previous engine mechanical tests, leverages the transfer function and a new mechanical environment to predict the response without conducting related experiments.
[0027] This invention applies engine test data and estimated response. By comparison, if the data is covered, no related tests are needed, and the conclusion that the engine is adapted to the mechanical environment can be directly obtained, greatly reducing costs. If the data is not covered, local finite element simulation calculations and supplementary tests can be used to verify the engine's adaptability to the mechanical environment, greatly reducing the scale of mechanical tests. Attached Figure Description
[0028] Figure 1 This is a flowchart illustrating the method for analyzing the mechanical environment adaptability of the same type of engine to multiple types of rockets according to the present invention.
[0029] Figure 2 This is a flowchart of the rocket mechanical environment adaptability analysis method for the improved engine of this invention.
[0030] Figure 3 This is a comparison diagram of the old and new mechanical environments of the present invention.
[0031] Figure 4 This is a power spectral density diagram of the vibration data from the test run of this invention.
[0032] Figure 5 This is the predicted response diagram for the present invention.
[0033] Figure 6 This is a comparison chart of the test response and the predicted response of the present invention. Detailed Implementation
[0034] This invention makes in-depth use of and explores previous engine mechanical tests and test runs. Based on the previous engine mechanical test data, it obtains the transfer functions of each position of the engine and, combined with the existing mechanical environment conditions, obtains the estimated main responses of each position of the engine. By comparing with the engine test run data, simulation analysis or supplementary tests are used to directly verify the engine's mechanical environment adaptability or reduce the scale of the tests.
[0035] like Figure 1 , 2 As shown, the present invention provides a method for analyzing the mechanical environment adaptability of a rocket engine, comprising:
[0036] 1) Compare the old and new mechanical environments of the engine to determine whether the original mechanical environment covers the new mechanical environment; if it covers, it proves that the engine can adapt to the new mechanical environment; if it does not cover, proceed to step 2).
[0037] 2) Based on previous engine mechanical test data, obtain the transfer functions of each major engine assembly; refer to previous engine mechanical test data, and take the mechanical test control input or the connection between the engine frame and the rocket body as the reference, calculate the transfer function G(f) = Y(f) / R(f) of each major engine assembly to the reference position, where Y(f) is the response curve of each major engine assembly and R(f) is the control curve.
[0038] 3) By using the transfer functions of each major engine component to the reference position and combining them with the new mechanical environment conditions, the predicted responses of each major engine component are obtained;
[0039] 4) Compare the estimated responses of the major engine components with the engine test vibration data, and use simulation analysis or conduct supplementary tests to determine the engine's mechanical environmental adaptability.
[0040] By conducting sinusoidal scanning tests, vibration tests, noise tests, and impact tests, it can be determined whether the original mechanical environment covers the new mechanical environment.
[0041] The determination of whether the original mechanical environment covers the new mechanical environment by conducting sinusoidal scanning tests, vibration tests, noise tests, and impact tests specifically includes:
[0042] For a sinusoidal scanning test, if A1(f)≥A2(f) is satisfied, it means that the original mechanical environment covers the new mechanical environment; where A1(f) is the acceleration amplitude corresponding to frequency f under the original mechanical environment condition, and A2(f) is the acceleration amplitude corresponding to frequency f under the new mechanical environment condition.
[0043] For vibration tests, if psd1(f)≥psd2(f) is satisfied, it means that the original mechanical environment covers the new mechanical environment; where psd1(f) is the power spectral density corresponding to frequency f under the original mechanical environment conditions, and psd2(f) is the power spectral density corresponding to frequency f under the new mechanical environment conditions.
[0044] For noise tests, if P1(f)≥P2(f), it means that the original mechanical environment covers the new mechanical environment; where P1(f) is the sound pressure amplitude corresponding to frequency f under the original mechanical environment conditions, and P2(f) is the sound pressure amplitude corresponding to frequency f under the new mechanical environment conditions.
[0045] For impact tests, if SRS1(f)≥SRS2(f), it means that the original mechanical environment covers the new mechanical environment; where SRS1(f) is the acceleration response value corresponding to frequency f under the original mechanical environment conditions, and SRS2(f) is the acceleration response value corresponding to frequency f under the new mechanical environment conditions.
[0046] For the same type of engine, if the original mechanical environment covers the new mechanical environment, it proves that the engine can adapt to the new mechanical environment; if it does not cover the new mechanical environment, proceed to step 2). For an improved engine, if the original mechanical environment covers the new mechanical environment, it proves that the unchanged part of the engine structure can adapt to the new mechanical environment, and the changed part proceeds to step 2); if it does not cover the new mechanical environment, proceed directly to step 2).
[0047] The term "same type of engine" refers to an engine with the same structure that is used in multiple types of rockets; the term "improved engine" refers to an engine with the same main power transmission path, the same overall engine mode and natural frequency as the original engine, but with other structural changes.
[0048] The main components include a frame, a constant level seat, a thrust chamber, a turbopump, a nozzle, and valves; the mechanical tests include modal tests, sinusoidal sweep tests, and random vibration tests.
[0049] The method of using the transfer function of each major engine assembly to the reference position and combining it with the new mechanical environment conditions to obtain the estimated response of each major engine assembly includes: for the obtained transfer function G(f), combining it with the new mechanical environment conditions R'(f), to obtain the response of each major engine assembly under the new mechanical environment conditions Y'(f) = G(f) × R'(f).
[0050] The process of comparing the estimated responses of each major engine component with engine test vibration data, and using simulation analysis or supplementary tests to determine the engine's adaptability to the mechanical environment includes: comparing the obtained responses Y'(f) of each major engine component with the responses A(f) at the same location in the same frequency band during engine testing; if Y'(f) ≤ A(f), the engine can adapt to the new mechanical environment; if Y'(f) > A(f), then using Y'(f) as the input load, performing local finite element simulation calculations, and judging its adaptability to the mechanical environment through finite element analysis; or conducting supplementary tests to verify the adaptability to the mechanical environment.
[0051] The simulation analysis described above is applicable to situations where there are relatively few components (less than 5) that do not cover the new mechanical environment. The specific process is as follows: Finite element modeling is used, with the actual installation state of the component on the engine as the boundary. For a component that is installed as a whole on a major assembly, the response Y'(f) at the major assembly is used as the input load. For a component that is installed at one end on a major assembly and at the other end on another major assembly, the larger response Y'(f) of the two is used as the input load. Dynamic strength calculation is performed to obtain the dynamic stress of the component. If the dynamic stress is less than the yield strength of the material, it can adapt to the new mechanical environment. Otherwise, the design is improved. The simulation is performed again after the design improvement until it adapts to the new mechanical environment.
[0052] The supplementary test is applicable when there are relatively many components (more than 5) that do not cover the new mechanical environment. The specific process is as follows: According to the actual installation state on the engine, the components that do not cover the new mechanical environment and their mounting bases are assembled into a whole. This whole is used as the test object. According to the sequence of the engine's main force transmission path, the response Y'(f) of the main assembly corresponding to the first force transmission path of the test object is used as the input load to carry out mechanical tests. After the test, the test object is inspected. If the test object's function and performance are intact, it indicates that the engine can adapt to the new mechanical environment. Otherwise, design improvements are made, and supplementary tests are carried out again until it adapts to the new mechanical environment.
[0053] The aforementioned method for analyzing the mechanical environment adaptability of rocket engines utilizes and mines engine test data and previous engine mechanical test data, combined with finite element simulation, to directly verify the mechanical environment adaptability of the engine or reduce the scale of mechanical tests, thereby effectively reducing mechanical tests and lowering development costs.
[0054] Taking a certain engine as an example, this invention conducts an engine mechanical environment adaptability analysis using the method described herein. The specific implementation process of this embodiment is as follows:
[0055] (1) Engine B is a dual-engine parallel engine, which is an improvement on the original engine A. Compared with engine A, the layout of the common part of engine B has changed, the structure of the single-engine swaying part is the same as that of engine A, the main force transmission path is the same, the overall engine mode and natural frequency are the same, so it is an improved engine.
[0056] (2) Compare the mechanical environment R'(f) that engine B needs to adapt to with the mechanical environment R1(f) that engine A needs to adapt to, such as... Figure 3 As shown in the figure, it is not covered in some frequency bands (1100-1400Hz).
[0057] (3) Review the previous mechanical test data of engine A, and obtain the transfer function according to the calculation method of transfer function G(f), such as... Figure 4 .
[0058] (4) Using the new mechanical environment R'(f) as the system input, the predicted response is obtained according to the response Y'(f) calculation method, such as... Figure 5 .
[0059] (5) Compare with the engine test response A(f) at the same location, such as Figure 6 The red line represents the engine test response A(f), which covers the predicted response in the 1100–1400 Hz frequency band. Engine B was tested as a single unit, with the single-unit swaying section participating in the test. Based on the above analysis, Y'(f) ≤ A(f), verifying the mechanical environment adaptability. Since the shared section between the two engines cannot be compared using test data, simulation analysis or supplementary tests are required. Due to the redesigned layout of the shared section, many components are not covered by the new mechanical environment. Mechanical tests were conducted on the shared section, and the functional performance was found to be intact after the tests, proving that the engine can adapt to the new mechanical environment.
[0060] According to the mechanical environment adaptability analysis method of the present invention, the mechanical test of the whole machine can be reduced to the mechanical test of the shared part of the two machines through analysis.
[0061] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention based on the above-disclosed technical content without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.
Claims
1. A method of analyzing the adaptability of a mechanical environment of a rocket engine, characterized by, The method comprises the following steps: 1) comparing the new and old mechanical environment of the engine to determine whether the original mechanical environment covers the new mechanical environment; If yes, it proves that the engine can adapt to the new mechanical environment; If no, go to step 2); 2) obtaining the transfer function of each main component of the engine according to the previous engine mechanical test data; referring to the previous mechanical test data of the engine, taking the mechanical test control input or the engine frame and the rocket body connection as the reference, the transfer function of each main component of the engine to the reference position is calculated; 3) using the transfer function of each main component of the engine to the reference position, combining with the new mechanical environment condition, the estimated response of each main component of the engine is obtained; 4) comparing the estimated response of each main component of the engine with the engine test vibration data, using simulation analysis or carrying out supplementary test to determine the mechanical environment adaptability of the engine.
2. The method of claim 1, wherein the method further comprises: The original mechanical environment is judged whether it covers the new mechanical environment by carrying out low-frequency sine sweep test, high-frequency vibration test, noise test and impact test.
3. The method of claim 2, wherein the method further comprises: The method of judging whether the original mechanical environment covers the new mechanical environment by carrying out sine sweep test, vibration test, noise test and impact test comprises the following steps: For sine sweep test, if A1(f)≥A2(f), it means that the original mechanical environment covers the new mechanical environment; wherein A1(f) is the acceleration amplitude corresponding to frequency f under the original mechanical environment condition, and A2(f) is the acceleration amplitude corresponding to frequency f under the new mechanical environment condition; For vibration test, if psd1(f)≥psd2(f), it means that the original mechanical environment covers the new mechanical environment; wherein psd1(f) is the power spectral density corresponding to frequency f under the original mechanical environment condition, and psd2(f) is the power spectral density corresponding to frequency f under the new mechanical environment condition; For noise test, if P1(f)≥P2(f), it means that the original mechanical environment covers the new mechanical environment; wherein P1(f) is the sound pressure amplitude corresponding to frequency f under the original mechanical environment condition, and P2(f) is the sound pressure amplitude corresponding to frequency f under the new mechanical environment condition; For impact test, if SRS1(f)≥SRS2(f), it means that the original mechanical environment covers the new mechanical environment; wherein SRS1(f) is the acceleration response value corresponding to frequency f under the original mechanical environment condition, and SRS2(f) is the acceleration response value corresponding to frequency f under the new mechanical environment condition.
4. The method of claim 1, wherein the method further comprises: For the same type of engine, if the original mechanical environment covers the new mechanical environment, it proves that the engine can adapt to the new mechanical environment; if not, go to step 2); for improved engine, if the original mechanical environment covers the new mechanical environment, it proves that the unchanged part of the engine structure can adapt to the new mechanical environment, and the changed part of the structure goes to step 2); if not, go to step 2) directly.
5. The method of claim 4, wherein the step of determining the mechanical environment of the rocket engine is performed by using a finite element analysis method. The same type of engine refers to the engine with the same structure and supporting multiple types of rockets; the improved engine refers to the engine with the same main transmission path, the same overall modal and natural frequency, and other changes in structure.
6. The method of claim 1, wherein the method further comprises: The main assembly includes a frame, a gimbal, a thrust chamber, a turbine pump, a nozzle, and a valve; and the mechanical test includes a modal test, a sine sweep test, and a random vibration test.
7. The method of claim 1, wherein the method further comprises: The estimated response of each main assembly of the engine is obtained by using the transfer function of each main assembly of the engine to the reference position and combining the new mechanical environment condition, and includes: for the obtained transfer function G(f)=Y(f) / R(f), where Y(f) is the response curve of each main assembly of the engine, and R(f) is the control curve; and the response Y’(f)=G(f)×R’(f) of each main assembly of the engine under the new mechanical environment condition is obtained by combining the new mechanical environment condition R’(f).
8. The method of claim 7, wherein the step of determining the mechanical environment of the rocket engine is performed by using a finite element analysis method. The adaptability of the engine to the new mechanical environment is determined by comparing the estimated response of each main assembly of the engine with the engine test vibration data, using simulation analysis, or carrying out a supplementary test, and includes: for the obtained response Y’(f) of each main assembly of the engine, the response A(f) of the same frequency band at the position during the engine test is compared, if Y’(f)≤A(f), the engine can adapt to the new mechanical environment; if Y’(f)>A(f), a local finite element simulation calculation is carried out with Y’(f) as the input load, and the adaptability to the mechanical environment is determined through finite element analysis; or a supplementary test is carried out to verify the adaptability to the mechanical environment.
9. The method of claim 8, wherein the step of determining the mechanical environment of the rocket engine is performed by using a finite element analysis method. The simulation analysis is suitable for the case where the number of components not covering the new mechanical environment is relatively small, and the specific process is: finite element modeling is used, the real installation state of the components on the engine is taken as the boundary, for the components installed on a main assembly, the response Y’(f) at the main assembly is taken as the input load, for the components installed at one end on a main assembly and at the other end on another main assembly, the larger response Y’(f) is taken as the input load, dynamic strength calculation is carried out to obtain the dynamic stress of the components, if the dynamic stress is less than the material yield strength, the engine can adapt to the new mechanical environment, otherwise, design improvement is carried out, and simulation is carried out again after the design improvement until the engine adapts to the new mechanical environment.
10. The method of claim 9, wherein the step of determining the mechanical environment of the rocket engine is performed by the steps of: determining a plurality of mechanical environment parameters of the rocket engine; and determining a plurality of mechanical environment parameter values of the rocket engine. The supplementary test is suitable for the case where the number of components not covering the new mechanical environment is relatively large, and the specific process is: according to the actual installation state on the engine, the components not covering the new mechanical environment and their installation bases are assembled into an integral whole, the integral whole is taken as a test object, the response Y’(f) of the first main assembly corresponding to the test object along the main transmission path of the engine is taken as the input load, a mechanical test is carried out, the test object is inspected after the test, if the function and performance of the test object are good, it indicates that the engine can adapt to the new mechanical environment, otherwise, design improvement is carried out, and the supplementary test is carried out again after the design improvement until the engine adapts to the new mechanical environment.