Working condition evaluation method for rocket engine combustion chamber and nozzle high dynamic load test device

Abstract

The present invention discloses a working condition evaluation method for a rocket engine combustion chamber and nozzle strong dynamic load test device, comprising the steps of: pre-calculating and simulating to form a basic database, extracting a data information table; establishing a working condition evaluation model based on the basic database and the data information table; comparing the calculated data of the working condition evaluation model with the experimental data of the actual test to obtain the difference, and calculating and analyzing to obtain the correction coefficient to correct and update the working condition evaluation model. The present invention adopts a cyclic update model method, pre-calculating the model to form a basic database, extracting a data information table, and establishing a working condition evaluation model based on the basic database and the data information table, using the working condition evaluation model to obtain the calculated data to evaluate the operating state, and comparing the experimental data of the actual test to obtain the correction coefficient, and using the correction coefficient to correct and update the working condition evaluation model to gradually improve the accuracy of the working condition evaluation model, so as to accurately reflect the actual strong dynamic load working condition.

Description

Technical Field

[0001] The invention relates to the technical field of rocket engines, and in particular to a working condition evaluation method for a rocket engine combustion chamber and a nozzle strong dynamic load test device. Background Art

[0002] The performance verification of the rocket engine combustion chamber and nozzle is extremely important, and the strong dynamic load test is one of the key links in the technology research and development process. The strong dynamic load test device of the rocket engine combustion chamber and nozzle is driven by high-pressure air and energetic medium. The high-pressure air provides the initial power, and the energy is further released through the combustion or explosion of the energetic medium. The collaborative work accurately simulates the strong dynamic load environment faced by the rocket engine during startup and actual operation, including extremely complex pressure, temperature, speed, etc.

[0003] The strong dynamic load test device for the combustion chamber and nozzle of a rocket engine is a typical pulse test device, but the computational simulation of its strong dynamic load environment is quite difficult, and the complex structural evolution in the flow field may even cause damage to the instrument, and even make it difficult to accurately control the timing of system control, measurement and acquisition during the test, which makes it extremely difficult to measure and evaluate the state of the strong dynamic load environment, and also causes a large deviation in the working condition measurement. In addition, due to the complexity of the strong dynamic load test, the measurement methods and the number of sensors are relatively insufficient, and the data information obtained from the strong dynamic load test device and the test of the combustion chamber and nozzle of the rocket engine is also very limited.

[0004] Therefore, there is an urgent need for a working condition evaluation method for a rocket engine combustion chamber and nozzle high dynamic load test device to make up for the deficiencies in test measurements. Summary of the invention

[0005] The purpose of the present invention is to provide a working condition evaluation method for a rocket engine combustion chamber and nozzle strong dynamic load test device to solve the technical problems in the prior art.

[0006] In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

[0007] The working condition evaluation method of the rocket engine combustion chamber and nozzle strong dynamic load test device includes the following steps:

[0008] Step 100: Based on the equivalent calculation simulation method of the strong dynamic load environment driven by high-pressure air and energetic medium, after pre-calculating and simulating to form a basic database of the flow field details evolving over time, the basic database is refined to obtain a data information table;

[0009] Step 200: establishing a working condition evaluation model based on the basic database and the data in the data information table, inputting test conditions into the working condition evaluation model, and obtaining calculation data for evaluating strong dynamic load working conditions;

[0010] Step 300: Perform a strong dynamic load test under the same test conditions to obtain test data, compare the test data under the same conditions with the calculated data, calculate and analyze the difference between the test data and the calculated data, and calculate and obtain a correction coefficient based on the difference between the test data and the calculated data, and use the correction coefficient to correct and update the operating condition assessment model.

[0011] As a preferred solution of the present invention, in step 100, the specific method of precalculating and simulating the basic database of the flow field details evolving over time is:

[0012] Through computer simulation and equivalent calculation methods, fluid simulation is performed to capture the flow characteristics of the strong dynamic load test device, establish a basic database of pressure, density, velocity and temperature of the flow field, and perform detailed solutions.

[0013] As a preferred solution of the present invention, in step 100, the specific method of extracting and obtaining the data information table based on the basic database is:

[0014] According to the results of the detailed solution, the shock wave is identified and extracted based on the gradient of density, pressure and velocity;

[0015] Information data is extracted based on the shock wave, and the information data includes the shock wave arrival timing, propagation direction, and thermodynamic state.

[0016] As a preferred solution of the present invention, in step 200, the specific method of establishing the operating condition evaluation model based on the basic database and the data in the data information table is:

[0017] Associating the data information table with the shock wave arrival timing, propagation direction, and thermodynamic state in the basic database;

[0018] The reliability of the data information table is confirmed by using the existing data, and the corresponding contents of the basic database and the data information table are extracted respectively to compare the specific arrival timing, propagation speed, propagation direction, and thermodynamic state.

[0019] As a preferred solution of the present invention, in step 300, based on the difference between the test data and the calculated data, the specific method of calculating and obtaining the correction coefficient is:

[0020] Perform calculations and test verification on the basic database and the data information table to confirm data reliability, and compare the differences between the data information table and experimental data according to test conditions;

[0021] Correct the relevant data in the data information table, take the experimental data as a benchmark, and use the inverse of the ratio of the relevant data in the data information table to the benchmark as a correction coefficient.

[0022] As a preferred solution of the present invention, in step 300, the specific method of using the correction coefficient to correct the operating condition assessment model and update the operating condition assessment model is:

[0023] The operating status data is obtained according to the data information table, and compared with a large amount of measured data, and fitted by the least square method or a similar method to determine the comprehensive correction coefficient, and the data information table is appropriately adjusted according to the correction coefficient.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention adopts a cyclic model updating method, pre-calculates the model to form a basic database, then extracts and obtains a data information table, and establishes a working condition evaluation model based on the basic database and the data information table. The working condition evaluation model is used to obtain calculated data to evaluate the operating status, and the correction coefficient is obtained by comparing the experimental data of the actual test. The working condition evaluation model is corrected and updated using the correction coefficient to gradually improve the accuracy of the working condition evaluation model, thereby accurately reflecting the actual strong dynamic load working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0027] Figure 1 A schematic flow chart of a method for evaluating the operating conditions of a rocket engine combustion chamber and nozzle high dynamic load test device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] 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.

[0029] like Figure 1 As shown, the present invention provides a working condition evaluation method for a rocket engine combustion chamber and nozzle strong dynamic load test device, comprising the following steps:

[0030] Step 100: Based on the equivalent calculation simulation method of the strong dynamic load environment driven by high-pressure air and energetic medium, after pre-calculating and simulating to form a basic database of the flow field details evolving over time, the basic database is refined to obtain a data information table;

[0031] Step 200: establishing a working condition evaluation model based on the basic database and the data in the data information table, inputting test conditions into the working condition evaluation model, and obtaining calculation data for evaluating strong dynamic load working conditions;

[0032] Step 300: Perform a strong dynamic load test under the same test conditions to obtain test data, compare the test data under the same conditions with the calculated data, calculate and analyze the difference between the test data and the calculated data, and calculate and obtain a correction coefficient based on the difference between the test data and the calculated data, and use the correction coefficient to correct and update the working condition assessment model.

[0033] The working condition evaluation method of the rocket engine combustion chamber and nozzle strong dynamic load test device of the present invention is mainly based on a theoretical equivalent calculation simulation method. A large number of simulation calculations are carried out in advance to obtain a large amount of data to form a basic database of the flow field details evolving over time. The basic database is refined to obtain a data information table, so that the basic database and the data information table are associated to establish a working condition evaluation model. Based on this working condition evaluation model, tests with corresponding conditions are set to measure and obtain test data. The test data are compared with the calculated data of the working condition evaluation model to obtain a difference value. According to the difference value, a correction coefficient can be analyzed and calculated to correct the working condition evaluation model, thereby improving the reliability of the working condition evaluation model and making it more accurately reflect the actual strong dynamic load environment.

[0034] Among them, the data information table includes the shock wave arrival timing, direction, thermodynamic state changes, etc.

[0035] Among them, the combined drive method of the present invention can more accurately simulate the actual strong dynamic load environment because it takes into account multiple energy sources and interactions. During the computational simulation process, the changes in various parameters in the flow field, including pressure, temperature, density, velocity, etc., are recorded in detail, forming a basic database of a large number of flow field details and their evolution over time.

[0036] In order to achieve accurate simulation, it is necessary to conduct in-depth research on the characteristics of high-pressure air and energetic media. For example, for high-pressure air, its state equation and compressibility at different pressures and temperatures should be considered; for energetic media, its energy release law and reaction kinetics should be studied.

[0037] At the same time, in the simulation process, advanced numerical calculation methods, such as finite volume method, finite difference method, etc., should be used to improve the accuracy and efficiency of calculation. Through a large number of simulation calculations, flow field evolution data under different initial conditions and boundary conditions can be obtained, providing rich data support for subsequent test state evaluation.

[0038] In step 100, the specific method of precalculating and simulating the basic database of the flow field details evolving over time is as follows:

[0039] Through computer simulation and equivalent calculation methods, fluid simulation is performed to capture the flow characteristics of the strong dynamic load test device, establish a basic database of pressure, density, velocity and temperature of the flow field, and perform detailed solutions.

[0040] Specifically, computational fluid simulation is performed through self-written codes, CFD software or CAE software, and the flow characteristics include the movement direction and speed of the shock wave. This method is used to establish a basic database with low cost and can calculate many working conditions.

[0041] For example, under atmospheric pressure conditions, 0.1-100kg of energetic media are used to drive the flow field and capture the shock wave motion state.

[0042] Among them, in step 100, the specific method of obtaining the data information table based on the basic database is:

[0043] According to the results of the detailed solution, the shock wave is identified and extracted based on the gradient of density, pressure and velocity;

[0044] Information data is extracted based on the shock wave, and the information data includes the shock wave arrival timing, propagation direction, and thermodynamic state.

[0045] This data information table will contain information that is crucial to the status evaluation of the high dynamic load test device for the rocket engine combustion chamber and nozzle, such as the arrival timing and direction of the shock wave, the change of thermodynamic state, etc. By collating and summarizing these key information, the test status can be analyzed more conveniently.

[0046] The arrival sequence of shock waves can directly read the time when the shock waves arrive at a specific location based on the calculation simulation results;

[0047] The shock wave velocity is calculated using the following formula:

[0048] ;

[0049] in, for The displacement of time, for The displacement at the moment, the propagation direction is directly read according to the calculation simulation results;

[0050] Thermodynamic state changes are directly read from the computational simulation results to obtain information on pressure, density and temperature at a specific location and their changes over time.

[0051] Among them, in step 200, the specific method of establishing the working condition evaluation model based on the data in the basic database and the data information table is:

[0052] Establish association between the data information table and the shock wave arrival timing, propagation direction, and thermodynamic state in the basic database;

[0053] The reliability of the data information table is confirmed through the existing data, and the corresponding contents of the basic database and data information table are extracted respectively to compare the specific arrival timing, propagation speed, propagation direction, and thermodynamic state.

[0054] The working condition assessment model is to establish an association between the data information table and the basic database. This association allows you to quickly obtain more detailed data from the basic database when querying the data information table. For example, when you need to know the detailed flow field information of the change in the direction of the shock wave at a certain moment, you can call out the corresponding flow field data from the basic database through the index in the data information table. This design not only improves the efficiency of data query, but also ensures the integrity and traceability of the data.

[0055] In step 300, based on the difference between the test data and the calculated data, the specific method of calculating and obtaining the correction coefficient is:

[0056] Perform calculations and test verification on the basic database and data information table to confirm the data reliability, and compare the differences between the data information table and the experimental data according to the test situation;

[0057] Correct the relevant data in the data information table, take the experimental data as the benchmark, and use the inverse of the ratio of the relevant data in the data information table to the benchmark as the correction coefficient.

[0058] The above working condition assessment model is verified by combining theory and some experiments. From a theoretical perspective, the simulation results are analyzed using existing physical laws and mathematical models to check whether the data conforms to basic physical principles. From an experimental perspective, some targeted experiments are carried out to compare the test data with the simulation data in the database. During the verification process, if deviations are found in the data, appropriate corrections are made based on the test conditions and engineering experience. For example, if the time it takes for the shock wave to arrive at a certain position is different from the simulation data, possible reasons can be analyzed, such as the influence of the test environment, factors not considered in the model, etc., and then the data can be adjusted and the correction coefficient can be determined. Through this repeated verification and correction process, the reliability of the database and information table is improved, so that it can more accurately reflect the actual strong dynamic load environment.

[0059] In actual tests, the data information table of the operating condition assessment model is queried according to the initial operating conditions. For example, after determining the initial pressure of the test, the type and amount of the energetic medium, and other conditions, the corresponding shock wave arrival timing and other related information can be found in the data information table. Then this information is compared with the shock wave arrival timing difference obtained from the test. By comparing, the difference between the two can be evaluated. If the difference is small, it means that the test state is close to the expectation; if the difference is large, further analysis of the cause is required.

[0060] According to the size and nature of the difference, the actual correction factor can be determined. This correction factor will be used to adjust the test results and improve subsequent tests to improve the accuracy and reliability of the test.

[0061] For example: the measured speed is 1km / s and the numerical simulation is 1.1km / s, then the correction coefficient is set to 0.91, the reciprocal of 1.1.

[0062] Among them, in step 300, the specific method of using the correction coefficient to correct the operating condition assessment model and update the operating condition assessment model is:

[0063] The operating status data is obtained according to the data information table, and compared with a large amount of measured data, and fitted by the least square method or a similar method to determine the comprehensive correction coefficient, and the data information table is appropriately adjusted according to the correction coefficient.

[0064] Further, the operating status data is obtained according to the data information table of the working condition evaluation model and compared with some measured data. For example, in addition to the shock wave arrival timing, other parameters such as the change in thermodynamic state can also be compared. Through this multi-parameter comparison, the reliability of the data can be confirmed more comprehensively. If inconsistencies are found in the data during the comparison process, appropriate adjustments are made according to the correction factor when necessary. This adjustment can not only improve the accuracy of the current test data, but also provide a more accurate reference for future tests. By continuously looping this process, the measurement and evaluation methods of the test status can be continuously improved to better adapt to complex strong dynamic load environment tests.

[0065] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. A method for evaluating the working condition of a rocket engine combustion chamber and nozzle strong dynamic load test device, characterized in that: The steps include: Step 100: Based on the equivalent calculation simulation method of the strong dynamic load environment driven by high-pressure air and energetic medium, after pre-calculating and simulating to form a basic database of the flow field details evolving over time, the basic database is refined to obtain a data information table; Step 200: establishing a working condition evaluation model based on the basic database and the data in the data information table, inputting test conditions into the working condition evaluation model, and obtaining calculation data for evaluating strong dynamic load working conditions; Step 300: Perform a strong dynamic load test under the same test conditions to obtain test data, compare the test data under the same conditions with the calculated data, calculate and analyze the difference between the test data and the calculated data, and calculate and obtain a correction coefficient based on the difference between the test data and the calculated data, and use the correction coefficient to correct the working condition assessment model and update the working condition assessment model; In step 200, the specific method of establishing the operating condition evaluation model based on the basic database and the data in the data information table is: Associating the data information table with the shock wave arrival timing, propagation direction, and thermodynamic state in the basic database; The reliability of the data information table is confirmed by using the existing data, and the corresponding contents of the basic database and the data information table are extracted respectively to compare the specific arrival timing, propagation speed, propagation direction, and thermodynamic state.

2. The working condition evaluation method of the rocket engine combustion chamber and nozzle strong dynamic load test device according to claim 1 is characterized in that: In step 100, the specific method of precalculating and simulating the basic database of the flow field details evolving over time is as follows: Through computer simulation and equivalent calculation methods, fluid simulation is performed to capture the flow characteristics of the strong dynamic load test device, establish a basic database of pressure, density, velocity and temperature of the flow field, and perform detailed solutions.

3. The working condition evaluation method of the rocket engine combustion chamber and nozzle strong dynamic load test device according to claim 2 is characterized in that: In step 100, the specific method of extracting and obtaining the data information table based on the basic database is: According to the results of the detailed solution, the shock wave is identified and extracted based on the gradient of density, pressure and velocity; Information data is extracted based on the shock wave, and the information data includes the shock wave arrival timing, propagation direction, and thermodynamic state.

4. The working condition evaluation method of the rocket engine combustion chamber and nozzle strong dynamic load test device according to claim 1 is characterized in that: In step 300, based on the difference between the test data and the calculated data, the specific method of calculating and obtaining the correction coefficient is: Perform calculations and test verification on the basic database and the data information table to confirm data reliability, and compare the differences between the data information table and experimental data according to test conditions; Correct the relevant data in the data information table, take the experimental data as a benchmark, and use the inverse of the ratio of the relevant data in the data information table to the benchmark as a correction coefficient.

5. The working condition evaluation method of the rocket engine combustion chamber and nozzle strong dynamic load test device according to claim 4 is characterized in that: In step 300, the specific method of using the correction coefficient to correct the operating condition assessment model and update the operating condition assessment model is: The operating status data is obtained according to the data information table, and compared with a large amount of measured data, and fitted by the least square method or a similar method to determine the comprehensive correction coefficient, and the data information table is appropriately adjusted according to the correction coefficient.

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