A frequency characteristic test system and method for a flow regulator during dynamic level change

Abstract

The present invention discloses a frequency characteristic test system and method during the dynamic level change of a flow regulator, which relates to the technical field of rocket engine starting control and dynamic characteristics of flow regulators, in order to solve the problem that existing tests cannot obtain accurate frequency characteristics during the level change of a flow regulator. The frequency characteristic test system during the dynamic level change of a flow regulator includes: an excitation device, a flow regulator, a first controller, a second controller, and a measurement and control system; the measurement and control system sends a start instruction to the two controllers at the same time according to the delay characteristics of each controller; the exciter sweeps the frequency according to a preset frequency while the flow regulator is dynamically leveled; to simulate the external frequency disturbance received by the flow regulator during the level change; and the frequency characteristics of the flow regulator during the level change are determined according to the test data. The frequency characteristic test system during the dynamic level change of a flow regulator provided by the present invention is used to simulate the disturbance of the flow regulator received by the upstream / downstream components.

Description

Technical Field

[0001] The present invention relates to the technical field of rocket engine starting control and flow regulator dynamic characteristics, and in particular to a frequency characteristic test system and method during the dynamic level change process of a flow regulator. Background Art

[0002] The flow regulator is a critical component for starting control in liquid oxygen / kerosene staged combustion cycle liquid rocket engines. During engine startup, the flow regulator's dynamic switching action is required to rapidly ramp up engine operating conditions. During this process, the sensitive components within the flow regulator operate in a rapidly moving state. Because the flow regulator is located upstream of the fuel pump and downstream of the gas generator in the engine system, both exhibit complex frequency characteristics during engine startup: the fuel pump's frequency increases rapidly as engine operating conditions rapidly ramp up, while the gas generator exhibits low-frequency oscillations of approximately 40 to 200 Hz. Therefore, the flow regulator must ensure that its sensitive components operate reliably during dynamic switching, unaffected by the frequency characteristics of other upstream and downstream components, and effectively block the pulsating pressures generated by these components to avoid system-level coupled oscillations.

[0003] At present, in ground tests, only non-excitation tests can be carried out for the flow regulator stage shifting action. The upstream and downstream of the test process are under steady-state boundary conditions, and it is impossible to obtain the frequency characteristics of the flow regulator during the dynamic stage shifting process when the upstream and downstream components are frequency disturbed during actual engine operation. Summary of the Invention

[0004] The purpose of the present invention is to provide a frequency characteristic test system and method for a flow regulator during dynamic level change, which is used to simulate the environment in which the flow regulator is subject to frequency disturbances of upstream and downstream components during dynamic level change during engine startup, obtain the frequency characteristics of the flow regulator during dynamic level change, and the suppression effect on upstream and downstream pulsating pressures, thereby providing a basis for optimizing the design of sensitive elements of the flow regulator.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] In one aspect, the present invention provides a frequency characteristic test system for a flow regulator during dynamic level change, comprising: an excitation device, a flow regulator, a first controller, a second controller, and a measurement and control system;

[0007] The excitation device includes an exciter and a throttle ring, the throttle ring is connected to a pipeline at either end of the flow regulator, and the exciter and the throttle ring are connected through a pipeline;

[0008] The measurement and control system is used to send a start instruction to the first controller and the second controller according to the delay characteristics of the first controller and the second controller; the first controller is used to drive the flow regulator to perform a stage-changing motion according to the start instruction; the second controller is used to drive the exciter to perform a frequency sweep at a preset frequency while the flow regulator is performing a stage-changing motion according to the start instruction; the exciter is used to provide disturbance to the medium in the main path;

[0009] The throttle ring is used to control the discharge flow of the medium that generates disturbances in the exciter circuit, and by adjusting the ratio of the exciter circuit flow to the main circuit flow, the amplitude of the pressure pulsation disturbance applied to the main circuit is controlled, thereby simulating the external frequency disturbance to which the flow regulator is subjected during the stage switching process; a plurality of sensors are respectively configured for the flow regulator and the exciter, for measuring the pulsating pressure time domain signals of each measuring point of the flow regulator and the exciter during the test, and determining the frequency characteristics of the flow regulator during the stage switching process based on the pulsating pressure time domain signals of each measuring point.

[0010] Compared with the prior art, the present invention provides a frequency characteristic test system for a flow regulator in a dynamic level change process, comprising: an excitation device, a flow regulator, a first controller, a second controller and a measurement and control system, wherein the excitation device comprises an exciter and a throttle ring; the flow regulator is driven by the first controller to perform level change motion, and the second controller drives the exciter to perform frequency sweeping at a preset frequency; the measurement and control system sends a start instruction to the first controller and the second controller according to the delay characteristics of the first controller and the second controller, thereby ensuring the uniformity of the action instruction, and realizing that the excitation device performs level change motion according to the preset frequency when the flow regulator is dynamically level changed. The frequency is swept to generate frequency disturbance through the exciter. The throttle controls the discharge flow of the medium that generates disturbance in the exciter path. By adjusting the ratio of the exciter path flow to the main path flow, the amplitude of the pressure pulsation disturbance applied to the main path is controlled, so as to simulate the external frequency disturbance that the flow regulator is subjected to during the stage shifting process during the actual engine starting process. Multiple sensors are respectively configured for the flow regulator and the exciter to measure the pulsating pressure time domain signals of each measuring point of the flow regulator and the exciter during the test. The frequency characteristics of the flow regulator during the stage shifting process can be determined based on the pulsating pressure time domain signals of each measuring point. This system introduces pulsating pressure disturbances of a specific frequency range upstream or downstream of the flow regulator through the excitation device to simulate the pulsating pressure disturbances generated by other components upstream / downstream of the flow regulator during engine operation. This is closer to the actual engine operating conditions and the test data is more reliable. The determined frequency characteristics of the flow regulator can be used as the basis for optimizing the structure of the flow regulator's sensitive elements, providing an important reference for ensuring the working reliability of the dynamic stage shifting process of the engine starting flow regulator.

[0011] On the other hand, the present invention further provides a method for testing the frequency characteristics of a flow regulator during dynamic level switching. The method is applied to the above-mentioned frequency characteristics testing system during dynamic level switching of the flow regulator. The method for testing the frequency characteristics of a flow regulator during dynamic level switching of the flow regulator includes:

[0012] The measurement and control system sends a start instruction to the first controller and the second controller according to the delay characteristics of the first controller and the second controller;

[0013] The first controller drives the flow regulator to perform a stage-changing motion according to a start instruction;

[0014] The second controller drives the exciter in the excitation device to sweep the frequency at a preset frequency while the flow regulator switches the stage according to the start instruction, and the exciter provides disturbance to the medium in the pipeline;

[0015] The throttle in the excitation device controls the discharge flow of the medium that generates disturbances in the exciter circuit. By adjusting the ratio of the exciter circuit flow rate to the main circuit flow rate, the amplitude of the pressure pulsation disturbance applied to the main circuit is controlled, simulating the external frequency disturbances to which the flow regulator is subjected during the stage switching process.

[0016] The pulsating pressure time domain signals of each measuring point corresponding to the flow regulator and the exciter are collected during the test, and the frequency characteristics of the flow regulator during the switching process are determined according to the pulsating pressure time domain signals of each measuring point.

[0017] Compared with the prior art, the beneficial effects of the frequency characteristic test method during the dynamic level change of a flow regulator provided by the present invention are the same as the beneficial effects of the frequency characteristic test system during the dynamic level change of a flow regulator described in the above technical solution, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present invention and constitute a part 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:

[0019] Figure 1 A schematic diagram of the structure of a frequency characteristic test system during the dynamic level change process of a flow regulator provided by the present invention;

[0020] Figure 2 This is a flow chart of a frequency characteristic test method during the dynamic level change process of a flow regulator provided by the present invention.

[0021] Reference numerals:

[0022] 1- measurement and control system, 2- first controller, 3- second controller, 4- first motor, 5- flow regulator, 6- second motor, 7- actuator, 8- throttle ring, 9- filter, 10- inlet stop valve, 11- regulating valve, 12- outlet stop valve, 13- upstream placement position of the actuator device. DETAILED DESCRIPTION

[0023] To facilitate a clear description of the technical solutions of the embodiments of the present invention, the words "first" and "second" are used in the embodiments of the present invention to distinguish between identical or similar items with substantially the same functions and effects. For example, the first threshold and the second threshold are merely used to distinguish between different thresholds and do not limit their order. Those skilled in the art will understand that the words "first" and "second" do not limit the quantity or execution order, and the words "first" and "second" do not necessarily mean different.

[0024] It should be noted that, in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present invention should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0025] In the present invention, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can represent: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b, c can be single or multiple.

[0026] The flow regulator is a key component in engine starting control. During the engine starting process, it not only needs to ensure its own stable operation, but also needs to play a good barrier role for upstream and downstream components. However, current test runs can only conduct unstimulated tests on the flow regulator's stage shifting action. It is impossible to study the frequency characteristics and suppression effect of the flow regulator on external disturbances during the dynamic stage shifting process, and it is impossible to provide a basis for the optimization of the flow regulation component.

[0027] To address the above-mentioned issues, the present invention provides a frequency characteristic test system and method for a flow regulator during dynamic level shifting. This system can simulate the frequency characteristics of other components during engine startup while the flow regulator is dynamically level shifting, applying disturbance excitation within a specific frequency range upstream or downstream to obtain the frequency characteristics of the flow regulator during dynamic level shifting, as well as its suppressive effect on upstream and downstream pulsating pressures. This provides a reference for the design and optimization of the flow regulator, improves the flow regulator's anti-disturbance capability during rapid engine startup, and ensures that the flow regulator reliably and stably completes the startup level shifting action according to a preset program. This will be described below with reference to the accompanying drawings.

[0028] Figure 1 The schematic diagram of the frequency characteristic test system structure of a flow regulator during dynamic level change provided by the present invention is as follows: Figure 1 As shown, the frequency characteristic test system for the dynamic switching process of the flow regulator includes: a measurement and control system 1, a first controller 2, a second controller 3, a first motor 4, a flow regulator 5, a second motor 6, an excitation device consisting of an exciter 7 and a throttle 8, wherein the throttle 8 is connected to the pipeline at either end of the flow regulator 5, and the exciter 7 and the throttle 8 are connected through a pipeline; a filter 9, an inlet stop valve 10, a regulating valve 11, and an outlet stop valve 12; wherein the filter 9, the inlet stop valve 10, the flow regulator 5, the regulating valve 11, and the outlet stop valve 12 are connected in sequence through pipelines. The pipeline where the exciter is located is the exciter path, and the pipeline where the flow regulator is located is the main path.

[0029] Among them, the inlet stop valve 10 is arranged at the inlet of the flow regulator 5 connecting pipeline, which is used to control the circulation or closing of the main medium; when the inlet stop valve 10 and the outlet stop valve 12 are opened, a stable environment under the starting condition can be provided for the flow regulator 5 at the beginning of the test; the filter 9 is arranged upstream of the inlet stop valve 10, which is used to filter impurities in the test medium; the outlet stop valve 12 is arranged at the outlet of the flow regulator 5 connecting pipeline, which is used to control the circulation or closing of the main medium.

[0030] When testing the frequency characteristics of the flow regulator 5 when subjected to frequency disturbances of upstream components, set the excitation device to Figure 1 The excitation device is placed at position 13 upstream to simulate the pulsating pressure disturbance generated by the upstream components of the flow regulator 5. The regulating valve 11 is set between the excitation device and the outlet stop valve 12. The regulating valve 11 is used to adjust the flow resistance of the downstream pipeline of the flow regulator 5 to simulate the outlet pressure environment of the flow regulator under the engine starting condition. When the frequency characteristic test of the flow regulator 5 is carried out under the frequency disturbance of the downstream components, the excitation device is set as follows. Figure 1The flow regulator is shown downstream to simulate the pulsating pressure disturbance generated by the components downstream of the flow regulator 5. Figure 1 The situation where the excitation device is downstream of the flow regulator is shown.

[0031] For the frequency range of 30 to 300 Hz that is of particular concern during the dynamic switching of the flow regulator 5 during engine startup, the exciter 7 needs to complete a rapid frequency sweep change of 30 to 300 Hz within 1 second, thereby simulating the frequency characteristics of other components such as the fuel pump and gas generator during engine startup.

[0032] To achieve synchronization between the dynamic level shifting of flow regulator 5 and the rapid frequency conversion of actuator 7, the operational compatibility of first controller 2 and second controller 3 must be strictly controlled. Test system 1 simultaneously controls the timing signals of both controllers to ensure uniformity of action commands. It also precisely measures the time delay characteristics of the first and second controllers, ensuring that while the flow regulator dynamically shifts, the actuator delivers disturbances within a specific frequency range according to a pre-set program.

[0033] The measurement and control system 1 sends a start-up instruction to the first controller 2 and the second controller 3 according to the delay characteristics of the first controller 2 and the second controller 3; the first controller 2 is used to drive the flow regulator 5 to perform a stage-changing movement through the first motor 4 according to the start-up instruction; the second controller 3 is used to drive the exciter 7 to sweep the frequency at a preset frequency through the second motor 6 while the flow regulator 5 is performing a stage-changing movement according to the start-up instruction; the exciter 7 is used to provide disturbance to the medium in the main path; the throttle ring 8 is used to control the discharge flow of the medium disturbed by the exciter path, and by adjusting the ratio of the exciter path flow to the main path flow, the amplitude of the pressure pulsation disturbance applied to the main path is controlled, thereby simulating the external frequency disturbance to which the flow regulator 5 is subjected during the stage-changing process.

[0034] There are multiple sensors configured at the measuring points corresponding to the flow regulator and the actuator. The measuring points can be as follows: Figure 1 As shown in FIG1 , the pressure signals during the test are measured at the measuring points P1, P2, P3, P4, P5, P6, P7, ΔP1, ΔP2, ΔP3, ΔP4, ΔP5, ΔP6 and ΔP7, etc., which are used as the basis for judging the working parameters such as the flow rate and pressure drop of the flow regulator; the pulsating pressure time domain signals during the test are measured at the measuring points ΔP1, ΔP2, ΔP3, ΔP4, ΔP5, ΔP6 and ΔP7, etc., and after converting them into frequency domain signals, the frequency characteristics of the flow regulator during the switching process can be determined according to the frequency domain signals.

[0035] See also Figure 2The present invention provides a method for testing the frequency characteristics of a flow regulator during dynamic level switching. The method is applied to the above-mentioned frequency characteristics testing system for the flow regulator during dynamic level switching. The method for testing the frequency characteristics of a flow regulator during dynamic level switching includes the following steps:

[0036] Step 201: The measurement and control system sends a start instruction to the first controller and the second controller according to the delay characteristics of the first controller and the second controller.

[0037] As an optional method, before the test begins, the frequency characteristic test system of the flow regulator dynamic switching process needs to be adjusted to the initial state. Specifically, the first controller drives the flow regulator through the first motor to set the flow regulator to the engine starting condition, and the first controller monitors the flow regulator angle state in real time.

[0038] Open the inlet stop valve and the outlet stop valve to provide the flow regulator with a steady-state working environment under the starting condition, so that the flow regulator can work stably under the starting condition;

[0039] The second controller drives the exciter through the second motor to adjust the frequency of the pulsating pressure generated by the exciter to the starting frequency, and monitors the excitation frequency in real time through the second controller.

[0040] As an optional method, before the frequency characteristic test of the dynamic level change process of the flow regulator is performed, that is, before the test system sends an instruction, the time delay characteristics of the first controller and the second controller need to be tested. Specifically, the measurement and control system sends a start instruction to the first controller and records the time at this time, and records the time when the first controller drives the flow regulator to start the level change action. The time when the flow regulator starts the level change action minus the time when the start instruction is issued is the delay characteristic Δt1 of the first controller;

[0041] The measurement and control system sends a start command to the second controller to record the time at this time, and also records the time when the second controller drives the exciter to start frequency sweeping. The time when the exciter starts frequency sweeping minus the time when the start command is issued is the delay characteristic Δt2 of the second controller.

[0042] Assume that the time when the flow regulator starts the level change instruction is t1, and the time when the exciter starts the frequency sweep instruction is t2. Taking t1 as the reference, it is necessary to ensure that Δt2+t2=Δt1+t1, so as to ensure that the flow regulator and exciter controlled by the two controllers start the level change or frequency sweep action at the same time at Δt1+t1, that is, the actual start of the level change of the flow regulator is synchronized with the actual start of the rapid frequency sweep of the exciter.

[0043] Step 202: The first controller drives the flow regulator to perform a stage-shifting motion according to the start-up instruction.

[0044] Then, the flow resistance of the downstream pipeline of the flow regulator is adjusted by the regulating valve to simulate the outlet pressure environment of the flow regulator during engine operation and obtain pressure drop conditions similar to those in the engine.

[0045] Step 203: The second controller drives the exciter in the excitation device to sweep the frequency at a preset frequency while the flow regulator switches stages according to the start-up instruction, and the exciter provides disturbance to the medium in the main path.

[0046] Step 204: The throttle ring in the excitation device controls the discharge flow of the medium that generates disturbances in the exciter path, and controls the amplitude of the pressure pulsation disturbance applied to the main path by adjusting the ratio of the exciter path flow to the main path flow, thereby simulating the external frequency disturbance received by the flow regulator during the stage switching process.

[0047] Step 205: collecting the pulsating pressure time domain signals of each measuring point corresponding to the flow regulator and the actuator during the test, and determining the frequency characteristics of the flow regulator during the switching process based on the pulsating pressure time domain signals of each measuring point.

[0048] This method converts the pulsating pressure time domain signal of each measuring point into a frequency domain signal, and obtains the frequency characteristics of the flow regulator during the switching process based on the frequency domain signal. The specific steps are as follows:

[0049] The pulsating pressure time domain signals collected at each measuring point are acquired; the measuring points include at least P2 upstream and P3 downstream of the flow regulator, and P5 near the exciter. Wavelet transform or short-time Fourier transform is then used to convert the pulsating pressure time domain signals at each measuring point into frequency domain signals. A transfer function is then established based on the frequency domain signals of the exciter's corresponding measuring point and the flow regulator's corresponding measuring point. The transfer function establishment process involves extracting the amplitude from the frequency domain signal of the exciter's corresponding measuring point to obtain first amplitude data; extracting the amplitude from the frequency domain signal of the flow regulator's corresponding measuring point to obtain second amplitude data; and establishing a transfer function based on the ratio of the first amplitude data to the second amplitude data. Based on the amplitude-phase-frequency results of the transfer function, the nonlinear frequency characteristics of the flow regulator during the switching process and its attenuation effect on pulsating pressures of different frequencies are analyzed.

[0050] As can be seen from the above introduction to the test system and test method, the present invention establishes a test method that can be used to study the frequency characteristics of a flow regulator during dynamic stage transitions during engine startup, as well as the flow regulator's ability to suppress upstream and downstream pulsating pressures. First, by adjusting the flow resistance of the downstream piping system, the flow regulator's pressure drop is controlled, simulating the operating state of the flow regulator's sensitive element throughout the stage transition process, similar to that in an actual engine. Second, an excitation device is used to introduce pulsating pressure disturbances within a characteristic frequency range upstream or downstream of the flow regulator, simulating the pulsating pressure disturbances generated by other components upstream and downstream of the flow regulator during engine operation. Simultaneously, the excitation device can deliver disturbances within a specific frequency range according to a preset program while the flow regulator dynamically transitions. The test results obtained using the test system and test method provided by the present invention can serve as a basis for optimizing the structural design of the flow regulator's sensitive element, decoupling the frequency characteristics of the flow regulator's stage transition process from the engine system and effectively blocking upstream and downstream pulsating pressures, ultimately ensuring a high stability margin for the local system where the flow regulator resides during engine startup.

[0051] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art can understand and implement other variations of the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0052] Although the present invention has been described with reference to specific features and embodiments thereof, it will be apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the invention. Accordingly, this specification and drawings are merely illustrative of the invention as defined by the appended claims and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the invention. It will be apparent that various modifications and variations may be made to the present invention by those skilled in the art without departing from the spirit and scope of the invention. Thus, the present invention is intended to include such modifications and variations as fall within the scope of the claims of the present invention and their equivalents.

Claims

1. A frequency characteristic test system for a flow regulator during dynamic level change, characterized in that: include: An excitation device, a flow regulator, a first controller, a second controller, and a measurement and control system; the excitation device includes an exciter and a throttle ring, the throttle ring is connected to a pipeline at either end of the flow regulator, and the exciter and the throttle ring are connected through a pipeline; The measurement and control system is used to send a start instruction to the first controller and the second controller according to the delay characteristics of the first controller and the second controller; the first controller is used to drive the flow regulator to perform a stage-changing motion according to the start instruction; The second controller is used to drive the actuator to sweep the frequency at a preset frequency while the flow regulator switches stages according to the start instruction; The exciter is used to provide disturbance to the medium in the main path; The throttle ring is used to control the discharge flow of the medium that generates disturbances in the exciter circuit, and by adjusting the ratio of the exciter circuit flow to the main circuit flow, the amplitude of the pressure pulsation disturbance applied to the main circuit is controlled, thereby simulating the external frequency disturbance to which the flow regulator is subjected during the stage switching process; a plurality of sensors are respectively configured for the flow regulator and the exciter, for measuring the pulsating pressure time domain signals of each measuring point of the flow regulator and the exciter during the test, and determining the frequency characteristics of the flow regulator during the stage switching process based on the pulsating pressure time domain signals of each measuring point.

2. The frequency characteristic test system during the dynamic switching process of the flow regulator according to claim 1 is characterized in that: The system also includes: an inlet stop valve and an outlet stop valve, the inlet stop valve is arranged at the inlet of the flow regulator connecting pipeline, and the outlet stop valve is arranged at the outlet of the flow regulator connecting pipeline; the inlet stop valve and the outlet stop valve are used to provide a stable environment for the flow regulator under starting conditions when the test is started.

3. The frequency characteristic test system during the dynamic switching process of the flow regulator according to claim 2 is characterized in that: The system further includes a regulating valve, which is disposed between the flow regulator and the outlet shut-off valve and is used to adjust the flow resistance of a pipeline downstream of the flow regulator to simulate an outlet pressure environment of the flow regulator under engine starting conditions.

4. The frequency characteristic test system during the dynamic switching process of the flow regulator according to claim 1 is characterized in that: The exciter completes a sweep frequency change from thirty to three hundred Hz within one second.

5. A method for testing the frequency characteristics of a flow regulator during dynamic level switching, the method being applied to the frequency characteristics testing system for the flow regulator during dynamic level switching according to any one of claims 1 to 4, characterized in that: The frequency characteristic test method of the flow regulator during dynamic level change includes: The measurement and control system sends a start instruction to the first controller and the second controller according to the delay characteristics of the first controller and the second controller; The first controller drives the flow regulator to perform a stage-changing motion according to a start instruction; The second controller drives the exciter in the excitation device to sweep the frequency at a preset frequency while the flow regulator switches the stage according to the start instruction, and the exciter provides disturbance to the medium in the main path; The throttle in the excitation device controls the discharge flow of the medium that generates disturbances in the exciter circuit. By adjusting the ratio of the exciter circuit flow rate to the main circuit flow rate, the amplitude of the pressure pulsation disturbance applied to the main circuit is controlled, simulating the external frequency disturbances to which the flow regulator is subjected during the stage switching process. The pulsating pressure time domain signals of each measuring point corresponding to the flow regulator and the exciter are collected during the test, and the frequency characteristics of the flow regulator during the switching process are determined according to the pulsating pressure time domain signals of each measuring point.

6. The frequency characteristic test method during the dynamic level change process of the flow regulator according to claim 5, characterized in that: The measurement and control system sends a start instruction to the first controller and the second controller according to the delay characteristics of the first controller and the second controller, and also includes: The first controller drives the flow regulator to set the flow regulator to an engine starting state; Opening the inlet stop valve and the outlet stop valve to provide a steady-state working environment for the flow regulator under the starting condition, the inlet stop valve is arranged at the inlet of the flow regulator connecting pipeline, and the outlet stop valve is arranged at the outlet of the flow regulator connecting pipeline; The second controller drives the actuator to adjust the frequency of the pulsating pressure generated by the actuator to a starting frequency.

7. The frequency characteristic test method during the dynamic level change process of the flow regulator according to claim 5, characterized in that: The measurement and control system sends a start instruction to the first controller and the second controller according to the delay characteristics of the first controller and the second controller, and also includes: The measurement and control system sends a start instruction to the first controller, and determines the delay characteristic of the first controller according to the time when the first controller drives the flow regulator to start the stage switching action; The measurement and control system sends a start instruction to the second controller, and determines the delay characteristic of the second controller according to the time when the second controller drives the exciter to start the frequency sweep action.

8. The frequency characteristic test method during the dynamic switching process of a flow regulator according to claim 5, characterized in that: After the first controller drives the flow regulator to perform a stage-changing motion according to the startup instruction, the second controller drives the exciter in the excitation device to perform a frequency sweep at a preset frequency while the flow regulator is performing a stage-changing motion according to the startup instruction, further comprising: The regulating valve adjusts the flow resistance of the downstream pipeline of the flow regulator to simulate the outlet pressure environment of the flow regulator during the operation of the engine; the regulating valve is arranged between the flow regulator and the outlet stop valve.

9. The frequency characteristic test method during the dynamic level change process of the flow regulator according to claim 5, characterized in that: The collecting of the pulsating pressure time domain signals of each measuring point corresponding to the flow regulator and the exciter during the test, and determining the frequency characteristics of the flow regulator during the level switching process according to the pulsating pressure time domain signals of each measuring point, includes: Obtain the collected pulsating pressure time domain signal of each measuring point; Converting the pulsating pressure time domain signal of each measuring point into a frequency domain signal; A transfer function is established based on the frequency domain signal of the measuring point corresponding to the actuator and the frequency domain signal of the measuring point corresponding to the flow regulator; The frequency characteristics of the flow regulator during the stage change process are determined based on the transfer function.

10. The frequency characteristic test method during the dynamic level change process of the flow regulator according to claim 9, characterized in that: The step of establishing a transfer function based on the frequency domain signal of the measuring point corresponding to the exciter and the frequency domain signal of the measuring point corresponding to the flow regulator includes: Extracting the amplitude of the frequency domain signal of the corresponding measuring point of the exciter to obtain first amplitude data; Extracting the amplitude of the frequency domain signal corresponding to the measuring point of the flow regulator to obtain second amplitude data; A transfer function is established according to the ratio of the first amplitude data to the second amplitude data.

Images