Maximum unbalance test method and system for twin-rotor turboshaft engine

Abstract

The present invention discloses a maximum unbalance test method and system for a dual-rotor turboshaft engine, which first analyzes the rotor vibration mode and operating speed, clarifies the test content to be carried out on each rotor, and then formulates the design requirements of the vibration test plan for the whole machine, rotor / shaft system, accessories and pipelines, and then adopts the Np speed open-loop control mode to respectively carry out the gas generator rotor acceleration and deceleration test and the power turbine rotor acceleration and deceleration test according to the test content, and finally analyzes the vibration test data to verify the vibration level of each part. Since the present invention adopts the Np speed open-loop control, it avoids the power turbine rotor being affected by the airflow and changing with the speed change of the gas generator rotor, and also can make it possible to change the speed of the gas generator rotor without changing the speed of the power turbine rotor when the speed of the power turbine rotor changes, so that the gas generator rotor and the power turbine rotor can be verified separately to avoid interference.

Description

Technical Field

[0001] The present invention relates to the technical field of maximum imbalance testing, and in particular to a maximum imbalance testing method and system for a twin-rotor turboshaft engine, electronic equipment, and a computer-readable storage medium. Background Art

[0002] The maximum imbalance test is an important test in engine airworthiness certification. This test is used to simulate the maximum vibration level that may occur in the actual use of the engine. Through this test, the vibration limit value of the whole engine can be determined, and the vibration level of the rotor / shaft system, accessory unit and pipeline under the maximum imbalance can be determined, providing important support for explaining the vibration airworthiness compliance of these components. Among them, the rotor imbalance excitation is the main excitation of the vibration of the whole engine. After determining the maximum imbalance of the rotor, it is necessary to carry out the maximum imbalance test, formulate the test method and procedure, and determine the vibration test plan of the whole machine, rotor / shaft system, accessory unit and pipeline under the maximum imbalance, so as to achieve the test purpose, complete sufficient test verification, avoid the situation of inadequate verification, and provide a basis for compliance with vibration-related airworthiness clauses. However, the existing whole machine maximum unbalance test method adopts the common rotor acceleration and deceleration test, without considering the separate verification of the dual rotors, and there is interference between the dual rotors. For example, patent CN111473859B discloses a method for formulating the whole machine vibration limit value. After determining the maximum rotor imbalance, the acceleration and deceleration test in the whole machine maximum unbalance test is performed slowly from the minimum to the maximum allowable speed range, that is, the speed of each rotor needs to be adjusted from the minimum to the maximum allowable speed range. Since the power turbine rotor speed will be affected by the change in the gas generator rotor speed, and the adjustment of the power turbine rotor speed requires the change of the gas generator rotor speed, this method cannot achieve separate verification of the gas generator rotor and the power turbine rotor. In addition, the existing whole machine maximum unbalance test method does not further verify the vibration peak value, resulting in inadequate peak verification, and subsequent supplementary tests are required. In addition, the vibration peak value is usually directly used as the whole machine vibration limit value, without considering the interference of sudden factors, resulting in poor accuracy of the whole machine vibration limit value. In addition, the existing maximum unbalance test method for the whole machine does not propose how to formulate a specific vibration test plan for the whole machine, rotor / shaft system, accessory units and pipelines under the maximum unbalance. Summary of the invention

[0003] The present invention provides a maximum imbalance test method and system for a twin-rotor turboshaft engine, electronic equipment, and a computer-readable storage medium, which can realize separate verification of a gas generator rotor and a power turbine rotor to avoid interference.

[0004] According to one aspect of the present invention, a maximum imbalance test method for a twin-rotor turboshaft engine is provided, comprising the following contents:

[0005] Determine the test contents for gas generator rotors and power turbine rotors;

[0006] Develop vibration test plans for the complete machine, rotor / shaft system, accessories and piping;

[0007] According to the test content, the Np speed open-loop control mode is adopted to carry out the gas generator rotor acceleration and deceleration test and the power turbine rotor acceleration and deceleration test respectively, wherein the Np speed represents the power turbine rotor speed;

[0008] The vibration test data of the whole machine, rotor / shaft system, accessories and piping are analyzed to verify the vibration level of each part.

[0009] Furthermore, for the vibration measurement points of the whole machine, the unidirectional acceleration sensor is installed on the force transmission route of the rotor support-casing-mounting joint; for the rotor / shaft system vibration measurement points, the spring support at the cold end is selected for testing, and the strain gauge is pasted on the spring support at the support point; for the pipeline vibration measurement points, by carrying out finite element calculation of the pipeline vibration characteristics, the dangerous vibration mode is selected, and the strain gauge is pasted according to the calculated vibration stress distribution, and strain gauges are also added at the weak positions of the pipeline; for the accessory vibration measurement points, the three-axis acceleration sensor is installed on the force transmission route of the engine casing-accessory.

[0010] Furthermore, the process of performing the gas generator rotor acceleration and deceleration test using the Np speed open-loop control mode includes the following contents:

[0011] Start the engine first, stay at the ground slow speed state, and stabilize for a preset time; then, keep the power turbine rotor speed unchanged, and reduce the gas generator rotor speed to the minimum speed state; then, slowly accelerate the gas generator rotor speed to 0.8 times the working speed, stay for a preset time, and adjust the power turbine rotor speed to the working speed at the same time; then, keep the power turbine rotor speed unchanged, slowly accelerate the gas generator rotor speed to the maximum speed, and then pull down to slowly decelerate the gas generator rotor speed to 0.8 working speed and stay for a preset time; then, slowly reduce the gas generator rotor speed to the minimum speed state, and adjust the power turbine rotor speed to the slow speed at the same time; then adjust to the ground slow speed state and stay for a preset time; finally stop.

[0012] Furthermore, the process of performing the power turbine rotor acceleration and deceleration test using the Np speed open-loop control mode includes the following contents:

[0013] First, start the engine and keep it in the ground slow-speed state for a preset time; then, push up to accelerate the gas generator rotor speed to 0.8 times the working speed, adjust the power turbine rotor speed to the working speed, and keep it for a preset time; then, keep the power turbine rotor speed unchanged, accelerate the gas generator rotor speed to the working speed, and keep it for a preset time; then, keep the gas generator rotor speed unchanged, and slowly decelerate the power turbine rotor speed to the lower limit of the working speed fluctuation without stopping; then, continue to keep the gas generator rotor speed unchanged, and slowly accelerate the power turbine rotor speed to the upper limit of the working speed fluctuation without stopping; then, continue Keep the gas generator rotor speed unchanged, and slowly decelerate the power turbine rotor speed to the lower limit of the fluctuation of the working speed without stopping; then, continue to keep the gas generator rotor speed unchanged, and slowly accelerate the power turbine rotor speed to the working speed without stopping; then, keep the power turbine rotor speed unchanged, pull down the engine to decelerate the gas generator rotor speed to 0.95 times the working speed, and stay for a preset time; then, keep the power turbine rotor speed unchanged, pull down the engine to decelerate the gas generator rotor speed to 0.8 times the working speed, and stay for a preset time; then, pull down to the ground slow car state and stay for a preset time; finally stop.

[0014] Furthermore, for the vibration test data of the whole machine and the vibration test data of the accessories, a peak dwell test is required for the vibration peak value; for the vibration test data of the rotor / shaft system and pipeline, if the vibration stress converted from the vibration peak value exceeds the allowable stress value of high cycle fatigue, a peak dwell test is required.

[0015] Furthermore, the process of the peak dwell test includes the following:

[0016] Adopt Np speed closed-loop control mode, first start the engine to slow state and stay for a preset time, then select the rotor speed corresponding to the vibration peak of any vibration measuring point in the gas generator rotor acceleration and deceleration test or the power turbine rotor acceleration and deceleration test for the peak dwell test, and during the test, the speed of the other rotor is consistent with the speed corresponding to the peak in the corresponding acceleration and deceleration test spectrum.

[0017] Furthermore, when performing a peak dwell test on the whole machine vibration test data, the vibration peak value during the peak dwell test is selected as a reference to formulate the whole machine vibration limit value.

[0018] In addition, the present invention also provides a maximum unbalance test system for a twin-rotor turboshaft engine, comprising:

[0019] A test content determination module, used to determine the test content of the gas generator rotor and the power turbine rotor;

[0020] Test plan formulation module, used to formulate vibration test plans for the whole machine, rotor / shaft system, accessories and pipelines;

[0021] The acceleration and deceleration test module is used to perform the gas generator rotor acceleration and deceleration test and the power turbine rotor acceleration and deceleration test respectively according to the test content by adopting the Np speed open-loop control mode, wherein the Np speed represents the power turbine rotor speed;

[0022] The test data analysis module is used to analyze the vibration test data of the whole machine, rotor / shaft system, accessories and pipelines to verify the vibration level of each part.

[0023] In addition, the present invention also provides an electronic device, including a processor and a memory, wherein the memory stores a computer program, and the processor executes the steps of the above method by calling the computer program stored in the memory.

[0024] In addition, the present invention also provides a computer-readable storage medium for storing a computer program for performing a maximum imbalance test on a twin-rotor turboshaft engine, wherein the computer program executes the steps of the method described above when running on a computer.

[0025] The present invention has the following beneficial effects:

[0026] The maximum unbalance test method of the twin-rotor turboshaft engine of the present invention first analyzes the rotor vibration mode and the working speed, clarifies the test content to be carried out on each rotor, and then formulates the design requirements of the vibration test plan of the whole machine, rotor / shaft system, accessories and pipelines, and then according to the test content, adopts the Np speed open-loop control mode to respectively carry out the gas generator rotor acceleration and deceleration test and the power turbine rotor acceleration and deceleration test, and finally analyzes the vibration test data to verify the vibration level of each part. Since the present invention adopts the Np speed open-loop control, it avoids the power turbine rotor being affected by the airflow and changing with the speed change of the gas generator rotor, and also can make it possible to change the speed of the gas generator rotor without changing the speed of the power turbine rotor when the speed of the power turbine rotor changes, so that the gas generator rotor and the power turbine rotor can be verified separately to avoid interference.

[0027] In addition, the maximum unbalance test system for the twin-rotor turboshaft engine of the present invention also has the above advantages.

[0028] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0030] Figure 1 It is a flow chart of a maximum imbalance test method for a twin-rotor turboshaft engine according to a preferred embodiment of the present application;

[0031] Figure 2 It is a test spectrum schematic diagram of the acceleration and deceleration test of the gas generator rotor in the preferred embodiment of the present application;

[0032] Figure 3 It is a schematic diagram of a test spectrum of a power turbine rotor acceleration and deceleration test in a preferred embodiment of the present application;

[0033] Figure 4 It is a schematic diagram of the module structure of a maximum imbalance test system for a twin-rotor turboshaft engine according to another embodiment of the present application. DETAILED DESCRIPTION

[0034] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0035] Reference Figure 1 The preferred embodiment of the present application provides a maximum imbalance test method for a twin-rotor turboshaft engine, comprising the following contents:

[0036] Step S1: determining the test contents of the gas generator rotor and the power turbine rotor;

[0037] Step S2: Formulate a vibration test plan for the whole machine, rotor / shaft system, accessories and pipelines;

[0038] Step S3: According to the test content, the gas generator rotor acceleration and deceleration test and the power turbine rotor acceleration and deceleration test are respectively performed using the Np speed open-loop control mode, wherein the Np speed represents the power turbine rotor speed;

[0039] Step S4: Analyze the vibration test data of the whole machine, rotor / shaft system, accessories and pipelines to verify the vibration level of each part.

[0040] It can be understood that the maximum unbalance test method of the twin-rotor turboshaft engine of this embodiment first analyzes the rotor vibration mode and the operating speed, clarifies the test content to be carried out on each rotor, and then formulates the design requirements of the vibration test plan for the whole machine, rotor / shaft system, accessories and pipelines, and then according to the test content, the Np speed open-loop control mode is used to perform the gas generator rotor acceleration and deceleration test and the power turbine rotor acceleration and deceleration test respectively, and finally the vibration test data is analyzed to verify the vibration level of each part. Since the present invention adopts the Np speed open-loop control, it avoids the power turbine rotor being affected by the airflow and changing with the speed change of the gas generator rotor, and it can also make it possible to change the speed of the gas generator rotor without changing the speed of the power turbine rotor when the speed of the power turbine rotor changes, so that the gas generator rotor and the power turbine rotor can be verified separately to avoid interference.

[0041] It can be understood that in step S1, the test content analysis is carried out, and the test content to be carried out on each rotor is clarified through the rotor vibration mode and operating speed analysis, wherein the operating speed and critical speed / vibration mode of the gas generator rotor and the power turbine rotor are shown in Table 1.

[0042] Table 1. Operating speed and critical speed / vibration mode

[0043] Rotor Working speed Vibration shape to be verified Gas generator rotor Crossing the second critical First-order critical vibration mode: translation vibration mode, the front and rear correction surfaces of the rotor are in the same phase; second-order critical vibration mode: swing vibration mode, the front and rear correction surfaces of the rotor are in opposite phases; Power turbine rotor Crossing the second critical First-order critical vibration mode: overall bending, the front and rear correction surfaces of the rotor are in phase; second-order critical vibration mode: shaft bending, the front and rear correction surfaces of the rotor are in phase;

[0044] It can be seen that for the gas generator rotor, both the same phase and the opposite phase need to be verified by acceleration and deceleration tests, while for the power turbine rotor, only the same phase acceleration and deceleration test verification is required.

[0045] It can be understood that in step S2, a vibration test plan is formulated according to the vibration contents of the whole machine, rotor / shaft system, pipeline, and accessories that need to be verified in the maximum unbalance test. Among them, for the vibration measuring points of the whole machine, the unidirectional acceleration sensor is installed on the force transmission line of the rotor support-casing-mounting section. For the convenience of installation, the acceleration sensor is installed on the mounting edge between the two casings through the vibration measuring seat and fixed with bolts. In addition, the collected acceleration signal is converted into a vibration velocity signal through integration and recorded; for the vibration measuring points of the rotor / shaft system, the elastic support of the cold end (such as the front fulcrum of the gas generator rotor and the 2# fulcrum of the power turbine rotor) is selected for testing, and the strain gauge is pasted on the elastic support of the fulcrum. Only one elastic support needs to be tested for each rotor. In addition, for the collected dynamic strain signal, it is necessary to calculate the dynamic stress signal according to the elastic modulus and record it; for the pipeline vibration measuring points, the resonance frequency, vibration mode and vibration stress distribution are obtained by carrying out finite element calculation of the pipeline vibration characteristics. The results are distributed, and dangerous vibration modes are selected. Strain gauges are pasted according to the calculated vibration stress distribution. Strain gauges at weak positions of the pipeline (such as welds, joints, etc.) need to be added according to the pipeline processing status. In addition, for the collected pipeline dynamic strain signal, it is necessary to calculate the dynamic stress signal according to the elastic modulus and record it; for the accessory vibration measurement point, the three-way acceleration sensor is installed on the force transmission route of the engine casing-accessory. For the convenience of installation, the acceleration sensor is installed on the installation edge between the casing / accessory through the vibration measuring seat and fixed with bolts. For the collected acceleration signal, it needs to be converted into a vibration velocity signal through integration and recorded. In addition, the subsequent accessory environmental vibration test uses the signal measured by the sensor as the accessory load basis, but it needs to be kept consistent with the engine installation method in the component test. In addition, the execution order of step S2 and step S1 can also be performed simultaneously, or step S2 is executed before step S1.

[0046] In addition, according to the requirements of airworthiness clauses for starting, the time interval between cold start and hot start can also be formulated to fully consider the impact of cold / hot start conditions of the engine on vibration. For cold start, two tests are conducted and the parking time between the two tests is greater than 2 hours, and for hot start, two tests are conducted and the parking time between the two tests is less than 15 minutes.

[0047] It can be understood that the present invention clearly puts forward the design requirements for the vibration test plan of the whole machine, rotor / shaft system, accessories and pipelines, and performs vibration monitoring on the key parts of the engine, so that each part can be fully tested and verified to avoid the situation where the verification is not in place.

[0048] It can be understood that according to the test content determined in step S1, the gas generator rotor needs to be subjected to acceleration and deceleration tests in the same phase and in opposite phases, while the power turbine rotor only needs to be subjected to acceleration and deceleration tests in the same phase. In step S3, after determining the maximum imbalance of the gas generator rotor and the power turbine rotor, for the gas generator rotor, the same phase and opposite phase combinations are respectively adopted to carry out acceleration and deceleration tests on the gas generator rotor, and for the power turbine rotor, only the same phase combination is adopted to carry out acceleration and deceleration tests on the power turbine rotor. Moreover, when carrying out acceleration and deceleration tests, the Np speed open-loop control mode is adopted. Among them, the process of carrying out acceleration and deceleration tests on gas generator rotors using the Np speed open-loop control mode includes the following contents:

[0049] Start the engine first, stay at the ground slow speed state, and stabilize for a preset time; then, keep the power turbine rotor speed unchanged, and reduce the gas generator rotor speed to the minimum speed state; then, slowly accelerate the gas generator rotor speed to 0.8 times the working speed, stay for a preset time, and adjust the power turbine rotor speed to the working speed at the same time; then, keep the power turbine rotor speed unchanged, slowly accelerate the gas generator rotor speed to the maximum speed, and then pull down to slowly decelerate the gas generator rotor speed to 0.8 working speed and stay for a preset time; then, slowly reduce the gas generator rotor speed to the minimum speed state, and adjust the power turbine rotor speed to the slow speed at the same time; then adjust to the ground slow speed state and stay for a preset time; finally stop.

[0050] Specifically, the test spectrum of the gas generator rotor acceleration and deceleration test is as follows: Figure 2As shown, Ng represents the gas generator rotor speed, Np represents the power turbine rotor speed, the operating speed is defined as the maximum design speed, the operating speed of the gas generator rotor is R, and the operating speed of the power turbine rotor is D. In the slow-speed state, the gas generator rotor and the power turbine rotor each have a speed. First, start the engine, stay in the ground slow-speed state, and stabilize for 2 minutes; then, keep the Np speed unchanged, and reduce Ng to the minimum speed state; then, slowly accelerate Ng (not more than 0.2%×1.0 operating speed / s) to 0.8R, and adjust Np=100% at the same time, and stay for 2 minutes; then, keep the Np speed unchanged, push up the engine to make the Ng speed slowly (not more than 0.2%×1.0 operating speed / s) accelerate to the maximum speed, where, according to the airworthiness requirements, this maximum speed will be greater than the 1.0 operating speed of the combustion rotor, for example, set it to 1.03R. In addition, if the stress peak (i.e. the stress peak of the whole machine, rotor / shaft system, accessories, and pipelines) appears at the maximum speed and there is no downward trend in the stress value, it is necessary to push it up by another 2%, that is, the maximum speed is 1.05R; then, pull the engine down to slowly decelerate the Ng speed (not more than 0.2%×1.0 operating speed / s) to 0.8R; then, slowly reduce the Ng speed (not more than 0.2%×1.0 operating speed / s) to the minimum speed state, and at the same time adjust Np to the slow speed; then, adjust to the ground slow speed state, stay for 2 minutes; finally stop.

[0051] In addition, the process of performing the power turbine rotor acceleration and deceleration test using the Np speed open-loop control mode includes the following:

[0052] First, start the engine and keep it in the ground slow-speed state for a preset time; then, push up to accelerate the gas generator rotor speed to 0.8 times the working speed, adjust the power turbine rotor speed to the working speed, and keep it for a preset time; then, keep the power turbine rotor speed unchanged, accelerate the gas generator rotor speed to the working speed, and keep it for a preset time; then, keep the gas generator rotor speed unchanged, and slowly decelerate the power turbine rotor speed to the lower limit of the working speed fluctuation without stopping; then, continue to keep the gas generator rotor speed unchanged, and slowly accelerate the power turbine rotor speed to the upper limit of the working speed fluctuation without stopping; then, continue Keep the gas generator rotor speed unchanged, and slowly decelerate the power turbine rotor speed to the lower limit of the fluctuation of the working speed without stopping; then, continue to keep the gas generator rotor speed unchanged, and slowly accelerate the power turbine rotor speed to the working speed without stopping; then, keep the power turbine rotor speed unchanged, pull down the engine to decelerate the gas generator rotor speed to 0.95 times the working speed, and stay for a preset time; then, keep the power turbine rotor speed unchanged, pull down the engine to decelerate the gas generator rotor speed to 0.8 times the working speed, and stay for a preset time; then, pull down to the ground slow car state and stay for a preset time; finally stop.

[0053] Specifically, the test spectrum of the gas generator rotor acceleration and deceleration test is as follows: Figure 3 As shown, first start the engine, stay in the ground slow state, and stabilize for 2 minutes; then, push the engine upward to accelerate the Ng speed to 0.8R, and adjust the Np speed to D at the same time, and stabilize for 2 minutes; then, keep the Np speed unchanged, accelerate the Ng speed by R, and stabilize for 2 minutes; then, keep the Ng speed unchanged, and slowly decelerate the Np speed (not more than 0.2%×1.0 working speed / s) to Np=(1-X)D without stopping, where X represents the fluctuation coefficient, which is determined by the upper and lower limits of the working speed fluctuation allowed by the power turbine rotor, generally 0.05; then, continue to keep the Ng speed unchanged, and slowly accelerate the Np speed (not more than 0.2%×1.0 working speed / s) to Np=(1+X)D without stopping. In addition, if the stress peak (i.e., the whole machine, rotor / The stress peak of the shaft system, accessories and pipelines appears at the maximum speed and there is no downward trend in the stress value. It needs to be pushed up by another 2%, that is, the maximum speed is (1+X+0.02)D; then, continue to keep the Ng speed unchanged, and slowly decelerate the Np speed (not more than 0.2%×1.0 working speed / s) to Np=(1-X)D without stopping; then, continue to keep the Ng speed unchanged, and slowly accelerate the Np speed (not more than 0.2%×1.0 working speed / s) to Np=D without stopping; then, keep the Np speed unchanged, pull down the engine to decelerate the Ng speed to 0.95R, and stay stable for 2 minutes; then, keep the Np speed unchanged, pull down the engine to decelerate the Ng speed to 0.8R, and stay stable for 2 minutes; then pull the engine down to the ground slow car state and stay for 2 minutes; finally stop.

[0054] It can be understood that the present invention adopts Np speed open-loop control. When the gas generator rotor changes near the maximum speed, the power turbine rotor speed remains constant, and when the power turbine rotor speed changes near the maximum speed, the gas generator rotor speed remains constant, which avoids the power turbine rotor being affected by the airflow and changing with the speed change of the gas generator rotor. It can also make it unnecessary to change the speed of the gas generator rotor when the power turbine rotor speed changes, so that the gas generator rotor and the power turbine rotor can be verified separately to avoid interference. In addition, the present invention takes into account that the maximum unbalance test is carried out on the test bench, and the power turbine rotor as a power output device needs to be connected to the power absorption device of the test bench. The acceleration and deceleration test spectrum of the gas generator rotor and the power turbine rotor of the present invention takes into account the speed matching of the gas generator rotor and the power turbine rotor, and prevents the dual rotor speed of the acceleration and deceleration test from being too different from the actual working speed of the engine, thereby causing the connection between the engine and the test bench to be damaged, and avoids the test bench power absorption device being affected due to excessive torque or power mismatch at the connection, thereby causing damage to the test bench. In addition, the acceleration and deceleration test spectrum of the present invention has a comprehensive speed coverage range and is more fully verified. For example, the minimum speed Ng is lower than the slow speed during the ground test bench test. In addition, the power turbine rotor speed is generally a fixed operating speed, that is, fixed at D, while the test spectrum of the present invention takes into account the upper and lower limits of the operating speed fluctuation.

[0055] It can be understood that after the acceleration and deceleration test is completed in step S3, the vibration test data of the gas generator rotor acceleration and deceleration test in the same phase, the gas generator rotor acceleration and deceleration test in the opposite phase, and the power turbine rotor acceleration and deceleration test in the same phase can be obtained, and then the vibration test data of the whole machine, rotor / shaft system, accessories and pipelines obtained by the three acceleration and deceleration tests are analyzed respectively to verify the vibration level of each part. Among them, for the vibration test data of the whole machine and the vibration test data of the accessories, a peak dwell test is required for the vibration peak value; for the vibration test data of the rotor / shaft system and the pipeline, if the vibration stress converted from the vibration peak value exceeds the high cycle fatigue allowable stress value, a peak dwell test is required, and if the vibration stress converted from the vibration peak value does not exceed the high cycle fatigue allowable stress value, there is no need to perform a peak dwell test. In addition, for the vibration test data of the rotor / shaft system, the elastic support stress data under the cold and hot start conditions of the engine under different phase configurations can be statistically analyzed respectively, and the rotor critical speed distribution can be determined based on the peak value to verify the critical calculation results and verify that the rotor operating speed range has sufficient margin from the critical speed. The vibration level of the rotor at different design points under various working conditions can also be judged based on the rotor elastic support stress level to prove the magnitude of the rotor vibration.

[0056] Optionally, for the accessory vibration test data, a curve of the accessory vibration changing with the rotor speed can also be drawn and compared with the nearby environmental vibration test load spectrum. If the vibration response of the accessory environmental vibration test is greater than or equal to the vibration acceleration / velocity data of the accessory vibration measuring point in the maximum imbalance test of the whole machine, the accessory environmental vibration test load spectrum is determined to be feasible and the accessory environmental vibration test is valid. If the vibration response of the accessory environmental vibration test is less than the vibration acceleration / velocity data of the accessory vibration measuring point in the maximum imbalance test of the whole machine, the accessory environmental vibration test load spectrum needs to be modified and the accessory environmental vibration test is invalid.

[0057] It can be understood that the present invention can also generate a curve of accessory vibration changing with rotor speed based on the accessory vibration test data in the maximum unbalance test of the whole machine, and compare it with the load spectrum of the nearby environmental vibration test, so as to evaluate the effectiveness of the nearby environmental vibration test.

[0058] The process of the peak dwell test includes the following:

[0059] Adopt Np speed closed-loop control mode, first start the engine to slow state and stay for a preset time, then select the rotor speed corresponding to the vibration peak of any vibration measuring point in the gas generator rotor acceleration and deceleration test or the power turbine rotor acceleration and deceleration test for the peak dwell test, and during the test, the speed of the other rotor is consistent with the speed corresponding to the peak in the corresponding acceleration and deceleration test spectrum.

[0060] Specifically, the Np speed closed-loop control mode is adopted, the engine is first started to slow down for 2 minutes, and then the rotor speed corresponding to the vibration peak of any vibration measuring point in the gas generator rotor acceleration and deceleration test or the power turbine rotor acceleration and deceleration test is selected for the peak dwell test, and the speed of the other rotor during the test is consistent with the speed corresponding to the peak in the corresponding acceleration and deceleration test spectrum. Among them, step S3 completes three acceleration and deceleration tests, namely, the gas generator rotor acceleration and deceleration test in the same phase, the gas generator rotor acceleration and deceleration test in the opposite phase, and the power turbine rotor acceleration and deceleration test in the same phase. In each acceleration and deceleration test process, the whole machine vibration measuring point, the strain measuring point at the rotor support, the pipeline strain measuring point, and the accessory vibration measuring point will each have a vibration peak. It is necessary to select the rotor speed corresponding to the vibration peak of each measuring point for the peak dwell test, and the speed of the other rotor is consistent with the speed corresponding to the peak in the acceleration and deceleration test spectrum. For example, the Ng speed corresponding to the peak of the whole machine vibration measuring point in the gas generator rotor acceleration and deceleration test in the same phase is selected for the peak dwell test, and the Np speed is consistent with the speed corresponding to the peak in the gas generator rotor acceleration and deceleration test spectrum. The residence time of the peak dwell test is determined by the following formula: , T represents the residence time, Indicates the frequency corresponding to the dwell speed. When the dwell time is reached, pull down the engine to the slow state and stabilize for 2 minutes, then stop. In addition, when conducting the peak dwell test of the whole machine vibration test data, the vibration peak value during the peak dwell test is selected as the benchmark to formulate the whole machine vibration limit value. Since the whole machine vibration peak is further subjected to the peak dwell test, the whole machine vibration performance can be verified more accurately, eliminating the interference of sudden factors, and the formulated whole machine vibration limit value is more accurate and more in line with the actual situation of the engine. Of course, in actual applications, a weighting coefficient is usually used to multiply the vibration peak value during the peak dwell test as the whole machine vibration limit value to ensure the safety and reliability of the engine. The weighting coefficient is less than 1 and can be set according to actual needs. In addition, if the time of the peak dwell test does not reach the dwell time, it is determined that the high cycle fatigue performance of the component does not meet the requirements.

[0061] It can be understood that the present invention conducts a peak residence test for the vibration peak condition, which provides a verification basis for the high-cycle fatigue performance of the rotor bearing and the pipeline, and can also provide a basis for the formulation of the vibration limit value of the whole machine. The verification is more complete and avoids the situation where the peak verification is not in place and subsequent supplementary tests are required.

[0062] In addition, if Figure 4 As shown, another embodiment of the present invention further provides a maximum unbalance test system for a twin-rotor turboshaft engine, preferably using the maximum unbalance test method for a twin-rotor turboshaft engine as described above, comprising:

[0063] A test content determination module, used to determine the test content of the gas generator rotor and the power turbine rotor;

[0064] Test plan formulation module, used to formulate vibration test plans for the whole machine, rotor / shaft system, accessories and pipelines;

[0065] The acceleration and deceleration test module is used to perform the gas generator rotor acceleration and deceleration test and the power turbine rotor acceleration and deceleration test respectively according to the test content by adopting the Np speed open-loop control mode, wherein the Np speed represents the power turbine rotor speed;

[0066] The test data analysis module is used to analyze the vibration test data of the whole machine, rotor / shaft system, accessories and pipelines to verify the vibration level of each part.

[0067] It can be understood that the maximum unbalance test system of the dual-rotor turboshaft engine of this embodiment first analyzes the rotor vibration mode and the operating speed, clarifies the test content to be carried out on each rotor, and then formulates the design requirements of the vibration test plan for the whole machine, rotor / shaft system, accessories and pipelines, and then according to the test content, the Np speed open-loop control mode is used to perform the gas generator rotor acceleration and deceleration test and the power turbine rotor acceleration and deceleration test respectively, and finally the vibration test data is analyzed to verify the vibration level of each part. Since the present invention adopts the Np speed open-loop control, it avoids the power turbine rotor being affected by the airflow and changing with the speed change of the gas generator rotor, and it can also make it possible to change the speed of the gas generator rotor without changing the speed of the power turbine rotor when the speed of the power turbine rotor changes, so that the gas generator rotor and the power turbine rotor can be verified separately to avoid interference.

[0068] In addition, another embodiment of the present invention further provides an electronic device, including a processor and a memory, wherein the memory stores a computer program, and the processor executes the steps of the above method by calling the computer program stored in the memory.

[0069] In addition, another embodiment of the present invention further provides a computer-readable storage medium for storing a computer program for performing a maximum imbalance test on a twin-rotor turboshaft engine, wherein the computer program executes the steps of the method described above when running on a computer.

[0070] Common computer-readable storage media include: floppy disks, flexible disks, hard disks, magnetic tapes, any other magnetic media, CD-ROMs, any other optical media, punch cards, paper tapes, any other physical media with patterns of holes, random access memory (RAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), flash-erasable programmable read-only memory (FLASH-EPROM), any other memory chip or cartridge, or any other medium that can be read by a computer. Instructions can further be transmitted or received by a transmission medium. The term transmission medium may include any tangible or intangible medium that can be used to store, encode or carry instructions for execution by a machine, and includes digital or analog communication signals or intangible media that facilitate communication of the above instructions. Transmission media include coaxial cables, copper wire, and optical fiber, including the wires of a bus used to transmit a computer data signal.

[0071] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present application may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0072] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0073] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0074] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0075] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0076] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A maximum imbalance test method for a twin-rotor turboshaft engine, characterized in that: Includes the following: Determine the test contents of the gas generator rotor and the power turbine rotor. For the gas generator rotor, acceleration and deceleration tests in the same phase and opposite phase are required, while for the power turbine rotor, only acceleration and deceleration tests in the same phase are required; Develop vibration test plans for the whole machine, rotor / shaft system, accessories and pipelines. For the vibration measurement points of the whole machine, install the unidirectional acceleration sensor on the force transmission route of the rotor support-casing-mounting joint; for the vibration measurement points of the rotor / shaft system, select the spring support at the cold end for testing, and paste the strain gauge on the spring support at the support point; for the vibration measurement points of the pipeline, select the dangerous vibration mode by carrying out finite element calculation of the pipeline vibration characteristics, paste the strain gauge according to the calculated vibration stress distribution, and add strain gauges at the weak positions of the pipeline; for the vibration measurement points of the accessories, install the three-way acceleration sensor on the force transmission route of the engine casing-accessory; According to the test content, the Np speed open-loop control mode is adopted to carry out the gas generator rotor acceleration and deceleration test and the power turbine rotor acceleration and deceleration test respectively, wherein the Np speed represents the power turbine rotor speed; The vibration test data of the whole machine, rotor / shaft system, accessories and piping are analyzed to verify the vibration level of each part. For the vibration test data of the whole machine and accessories, a peak dwell test is required for the vibration peak value. For the vibration test data of the rotor / shaft system and piping, if the vibration stress converted from the vibration peak value exceeds the allowable stress value of high cycle fatigue, a peak dwell test is required.

2. The maximum unbalance test method of a twin-rotor turboshaft engine according to claim 1, characterized in that: The process of performing the gas generator rotor acceleration and deceleration test using the Np speed open-loop control mode includes the following: Start the engine first, and stay at ground speed for a preset time; Then, keep the power turbine rotor speed unchanged and reduce the gas generator rotor speed to the minimum speed state; then, slowly accelerate the gas generator rotor speed to 0.8 times the working speed, stay for a preset time, and adjust the power turbine rotor speed to the working speed; then, keep the power turbine rotor speed unchanged, slowly accelerate the gas generator rotor speed to the maximum speed, and then pull down to slowly decelerate the gas generator rotor speed to 0.8 working speed and stay for a preset time; Then, the gas generator rotor speed is slowly reduced to the minimum speed state, and the power turbine rotor speed is adjusted to the slow speed; then it is adjusted to the ground slow state and stays for a preset time; finally, the car is stopped.

3. The maximum unbalance test method of a twin-rotor turboshaft engine according to claim 1, characterized in that: The process of performing the power turbine rotor acceleration and deceleration test using the Np speed open-loop control mode includes the following: Start the engine first and keep it at ground speed for a preset time; Then, push up to accelerate the gas generator rotor speed to 0.8 times the working speed, adjust the power turbine rotor speed to the working speed, and stay for a preset time; then, keep the power turbine rotor speed unchanged, accelerate the gas generator rotor speed to the working speed, and stay for a preset time; Then, keep the gas generator rotor speed unchanged, and slowly decelerate the power turbine rotor speed to the lower limit of the fluctuation of the working speed without stopping; then, continue to keep the gas generator rotor speed unchanged, and slowly accelerate the power turbine rotor speed to the upper limit of the fluctuation of the working speed without stopping; then, continue to keep the gas generator rotor speed unchanged, and slowly decelerate the power turbine rotor speed to the lower limit of the fluctuation of the working speed without stopping; then, continue to keep the gas generator rotor speed unchanged, and slowly accelerate the power turbine rotor speed to the working speed without stopping; then, keep the power turbine rotor speed unchanged, pull down the engine to decelerate the gas generator rotor speed to 0.95 times the working speed, and stay for a preset time; then, keep the power turbine rotor speed unchanged, pull down the engine to decelerate the gas generator rotor speed to 0.8 times the working speed, and stay for a preset time; Then, pull down to the ground slow car state and stay for a preset time; finally stop.

4. The maximum imbalance test method of a twin-rotor turboshaft engine according to claim 1, characterized in that: The process of the peak dwell test includes the following: Adopt Np speed closed-loop control mode, first start the engine to slow state and stay for a preset time, then select the rotor speed corresponding to the vibration peak of any vibration measuring point in the gas generator rotor acceleration and deceleration test or the power turbine rotor acceleration and deceleration test for the peak dwell test, and during the test, the speed of the other rotor is consistent with the speed corresponding to the peak in the corresponding acceleration and deceleration test spectrum.

5. The maximum unbalance test method of a twin-rotor turboshaft engine according to claim 4, characterized in that: When conducting a peak dwell test on the whole machine vibration test data, the vibration peak value during the peak dwell test is selected as a benchmark to formulate the whole machine vibration limit value.

6. A maximum unbalance test system for a twin-rotor turboshaft engine, using the maximum unbalance test method for a twin-rotor turboshaft engine as claimed in any one of claims 1 to 5, characterized in that: include: A test content determination module, used to determine the test content of the gas generator rotor and the power turbine rotor; Test plan formulation module, used to formulate vibration test plans for the whole machine, rotor / shaft system, accessories and pipelines; The acceleration and deceleration test module is used to perform the gas generator rotor acceleration and deceleration test and the power turbine rotor acceleration and deceleration test respectively according to the test content by adopting the Np speed open-loop control mode, wherein the Np speed represents the power turbine rotor speed; The test data analysis module is used to analyze the vibration test data of the whole machine, rotor / shaft system, accessories and pipelines to verify the vibration level of each part.

7. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores a computer program, and the processor executes the steps of the method according to any one of claims 1 to 5 by calling the computer program stored in the memory.

8. A computer-readable storage medium for storing a computer program for performing a maximum imbalance test on a twin-rotor turboshaft engine, characterized in that: When the computer program is run on a computer, the steps of the method according to any one of claims 1 to 5 are executed.

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