CN115524000A - Test bench for testing acoustic transmission characteristics of port of vane pump - Google Patents

Abstract

The invention belongs to the technical field of experimental tooling, and specifically discloses a test bench for testing the acoustic transmission characteristics of a vane pump port, including a test pump, an auxiliary pump as a sound source, a water tank, a flow meter, a piezoelectric pressure sensor, a flow regulating valve I, Waterway regulating valves Ⅱ～Ⅻ and related piping systems. Use only one test pump, one auxiliary pump and related pipeline system, adjust the frequency conversion drive of the auxiliary pump, the opening of the flow regulating valve Ⅰ on the outlet pipeline of the auxiliary pump, and the opening of the water regulating valve Ⅱ～Ⅻ along the pipeline. It can complete the acoustic transmission characteristic test of the test pump port at different frequencies without disassembling the test pump and auxiliary pump, which reduces the workload and greatly improves the work efficiency.

Description

A test bench for testing the acoustic transmission characteristics of the vane pump ports

technical field

The invention belongs to the technical field of experimental tooling, in particular to a test bench for testing the acoustic transmission characteristics of a vane pump port.

Background technique

As the core equipment for fluid medium transportation in the waterway system, the vane pump has very important applications in the fields of urban municipal administration, food and medicine, chemical metallurgy, energy power, aviation and navigation. In recent years, with the development of vane pumps in various fields towards high power, high speed, high reliability, and centralization, as the most important source of noise in waterway systems, the research on the acoustic transmission characteristics of vane pump ports has important practical significance. Existing test benches usually use hydrophones or pressure sensors installed on the wall of the inlet and outlet pipes of the vane pump, and directly use the sound pressure measured at a certain position of the inlet and outlet pipes of the vane pump to reflect the acoustic transmission characteristics of the vane pump port . But this directly measured sound pressure depends not only on the monitoring position where the hydrophone or pressure sensor is installed, but also on the acoustic response of the piping system. That is to say, the measurement results may vary greatly depending on the system and measurement location, and cannot directly reflect the port acoustic transmission characteristics of the vane pump itself. It can be seen that the existing test bench still has great limitations in testing the acoustic transmission characteristics of the vane pump port.

Contents of the invention

In order to overcome the problems existing in the existing test technology, the present invention proposes a test bench for testing the acoustic transmission characteristics of the vane pump port, using only one test pump, one auxiliary pump as the sound source, two flowmeters, two sets of Piezoelectric pressure sensor and related pipeline system, by adjusting the frequency conversion drive of the auxiliary pump, the opening of the flow regulating valve Ⅰ on the outlet pipeline of the auxiliary pump, and the opening and closing of the waterway regulating valve Ⅱ～Ⅻ along the pipeline, change the auxiliary pump as Acoustic loads generated by external sound sources at different frequencies and different acoustic impedances of pipeline configurations, and acoustic loads of the upstream and downstream monitoring points at different frequencies of the test pump under different acoustic loads of external sound sources and different acoustic impedances of pipeline configurations. The pressure amplitude value, complete the modeling and solution of the test data, and obtain the acoustic transmission characteristics of the vane pump port at different frequencies through the test, and there is no need to disassemble the test pump and auxiliary pump during the process.

To achieve the above object, the present invention adopts the following technical solutions:

A test bench for testing the acoustic transmission characteristics of a vane pump port, including a test pump, an auxiliary pump as a sound source, a water tank, a flow meter, a piezoelectric pressure sensor, a flow regulating valve I, waterway regulating valves II-XII and related waterway systems;

The auxiliary pump and the test pump are connected through a pipeline, and the auxiliary pump and the test pump are connected to the water tank through the pipeline to form the main loop of the water circulation system; flow meters are installed on the outlet pipelines of the auxiliary pump and the test pump;

The test bench can be divided into a monitoring system and an adjustment control system. The monitoring system is composed of two groups of four piezoelectric pressure sensors, which are respectively located on the inlet and outlet pipelines of the test pump. Each group includes two pressure sensors. The electric pressure sensor is used to monitor the sound pressure signals at different frequencies excited by the auxiliary pump at the inlet pipeline and the outlet pipeline of the test pump; the adjustment control system includes the first water circuit between the auxiliary pump and the test pump Regulating valve group and flow regulating valve Ⅰ on the outlet pipeline of the auxiliary pump, the second waterway regulating valve group between the test pump and the water tank and waterway regulating valve Ⅸ on the outlet pipeline of the test pump; the regulation The control system adjusts the external sound source or external acoustic impedance received by the test pump; the first waterway regulating valve group includes waterway regulating valve IV, waterway regulating valve V and waterway regulating valve VI, waterway regulating valve IV and waterway regulating valve set in parallel The two sides of valve V are respectively connected in series with waterway regulating valve II and waterway regulating valve VII, and the two sides of waterway regulating valve V and waterway regulating valve VI are respectively connected in series with waterway regulating valve III and waterway regulating valve VIII; the second waterway regulating valve The group includes waterway regulating valve Ⅹ, waterway regulating valve Ⅺ and waterway regulating valve Ⅻ arranged in parallel.

The adjustment step of the adjustment system includes: adjusting the variable frequency drive of the auxiliary pump to change its speed, and then changing the sound pressure amplitude and frequency of the auxiliary pump as a sound source; controlling the opening of the flow regulating valve I on the outlet pipeline of the auxiliary pump, Then change the sound pressure amplitude of the auxiliary pump as the sound source; adjust the different waterway regulating valves Ⅱ～Ⅻ on the branch pipeline between the test pump and the auxiliary pump, so that the pipeline configuration has different acoustic impedance.

The waterway system also includes circuits I, II, III, IV, V, VI, VII, VIII, IX, X, XI, and XII.

In circuit Ⅰ, flow regulating valve Ⅰ, waterway regulating valve Ⅱ, waterway regulating valve Ⅲ, waterway regulating valve Ⅵ, waterway regulating valve Ⅸ, waterway regulating valve Ⅹ are opened, and other waterway regulating valves are closed.

In circuit II, the flow regulating valve I, waterway regulating valve II, waterway regulating valve V, waterway regulating valve VIII, waterway regulating valve IX, and waterway regulating valve X are opened, and the remaining waterway regulating valves are closed.

In circuit III, the flow regulating valve Ⅰ, waterway regulating valve Ⅳ, waterway regulating valve Ⅶ, waterway regulating valve Ⅷ, waterway regulating valve Ⅸ, waterway regulating valve Ⅹ are opened, and other waterway regulating valves are closed.

In loop IV, flow control valve Ⅰ, water channel control valve III, water channel control valve IV, water channel control valve V, water channel control valve Ⅵ, water channel control valve VII, water channel control valve Ⅸ, water channel control valve Ⅹ are opened, and other water channel control valves are closed.

Circuit Ⅴ is flow regulating valve Ⅰ, waterway regulating valve Ⅱ, waterway regulating valve Ⅲ, waterway regulating valve Ⅵ, waterway regulating valve Ⅸ, waterway regulating valve Ⅺ open, and other waterway regulating valves are closed.

In circuit Ⅵ, flow regulating valve Ⅰ, waterway regulating valve Ⅱ, waterway regulating valve Ⅴ, waterway regulating valve Ⅷ, waterway regulating valve Ⅸ, waterway regulating valve Ⅺ are opened, and other waterway regulating valves are closed.

In circuit VII, the flow regulating valve Ⅰ, waterway regulating valve Ⅳ, waterway regulating valve Ⅶ, waterway regulating valve Ⅷ, waterway regulating valve Ⅸ, waterway regulating valve Ⅺ are opened, and other waterway regulating valves are closed.

In circuit Ⅷ, flow regulating valve Ⅰ, waterway regulating valve Ⅲ, waterway regulating valve Ⅳ, waterway regulating valve Ⅴ, waterway regulating valve Ⅵ, waterway regulating valve Ⅶ, waterway regulating valve Ⅸ, waterway regulating valve Ⅺ are opened, and other waterway regulating valves are closed.

In circuit Ⅸ, flow regulating valve Ⅰ, waterway regulating valve Ⅱ, waterway regulating valve Ⅲ, waterway regulating valve Ⅵ, waterway regulating valve Ⅸ, waterway regulating valve Ⅻ are opened, and other waterway regulating valves are closed.

In loop X, the flow regulating valve Ⅰ, waterway regulating valve Ⅱ, waterway regulating valve Ⅴ, waterway regulating valve Ⅷ, waterway regulating valve Ⅸ, waterway regulating valve Ⅻ are opened, and the rest of the waterway regulating valves are closed.

In loop Ⅺ, flow regulating valve Ⅰ, waterway regulating valve Ⅳ, waterway regulating valve Ⅶ, waterway regulating valve Ⅷ, waterway regulating valve Ⅸ, waterway regulating valve Ⅻ are opened, and other waterway regulating valves are closed.

In loop Ⅻ, flow regulating valve Ⅰ, waterway regulating valve Ⅲ, waterway regulating valve Ⅳ, waterway regulating valve Ⅴ, waterway regulating valve Ⅵ, waterway regulating valve Ⅶ, waterway regulating valve Ⅸ, waterway regulating valve Ⅻ are opened, and other waterway regulating valves are closed.

The waterway system also includes closing the waterway regulating valves IX in circuits I, II, III, IV, V, VI, VII, VIII, IX, X, XI, and XII, and keeping the other regulating valves unchanged.

The inlet and outlet pipelines of the test pump are respectively arranged in two groups of four piezoelectric pressure sensors in sequence, and the distance between each group of sensors at the inlet pipeline and the outlet pipeline is 10 to 20 times the inner diameter of the pipeline. The smaller the inner diameter, the larger the multiplier value, and the larger the inner diameter of the pipe, the smaller the multiplier value.

The beneficial effects of the present invention are:

The present invention proposes a test bench for testing the acoustic transmission characteristics of the vane pump port. By adjusting the frequency conversion drive of the auxiliary pump and the opening of the valve along the pipeline, only one test pump and one auxiliary pump are required as sound sources. , Two sets of piezoelectric pressure sensors and related pipeline systems can complete the acoustic transmission characteristic test of the vane pump port at different frequencies, which reduces the workload and can greatly improve the work efficiency and the accuracy of the test measurement. In the process of carrying out the test of the acoustic transmission characteristics of the vane pump port, the test bench can avoid the influence of the ambient background noise and the pump wall damping in the indirect measurement method. Differences in test systems and measurement locations lead to significant differences in measurement results. The test bench can directly reflect the acoustic characteristics of the vane pump itself, and provide a theoretical basis and scientific basis for the research on the noise mechanism of centrifugal pumps, the verification of noise reduction measures and the design of low-noise products.

The invention is verified by experiments and has good effect.

Description of drawings

Accompanying drawing 1 shows the system schematic diagram of the present invention;

Notes in the schematic diagram: The elliptical dotted frame A and the elliptical dotted frame B in the figure represent the regulating valve group. By adjusting the opening and closing of the waterway regulating valves Ⅱ～Ⅻ along the pipeline, the different acoustic impedances of the pipeline configuration can be changed;

1-auxiliary pump, 2-test pump, 3, 4-flow meter, 5, 6-piezoelectric pressure sensor, 7-flow regulating valve Ⅰ, 8-water regulating valve Ⅱ, 9-water regulating valve Ⅲ, 10- Waterway regulating valve Ⅳ, 11-waterway regulating valve Ⅴ, 12-waterway regulating valve Ⅵ, 13-waterway regulating valve Ⅶ, 14-waterway regulating valve Ⅷ, 15-waterway regulating valve Ⅸ, 16-waterway regulating valve Ⅸ, 17-waterway Regulating valve Ⅺ, 18-waterway regulating valve Ⅻ, 19-water tank.

detailed description

Now in conjunction with accompanying drawing 1 the concrete implementation method of the present invention is described:

The waterway system of the test bench is composed of an auxiliary pump 1, a test pump 2, a flow meter 3 (4), a flow regulating valve I7, a waterway regulating valve II～Ⅻ (8～18) and a water tank 19. The auxiliary pump 1 and the test The pump 2 is connected through pipelines, and the auxiliary pump 1 and the test pump 2 are connected with the water tank 19 through pipelines to form the main circuit of the water circulation system; the outlet pipelines of the auxiliary pump 1 and the test pump 2 are equipped with flow meters 3 and flowmeter4.

The test bench can be divided into a monitoring system and a regulation control system. The monitoring system is composed of two groups of four piezoelectric pressure sensors, one of which is composed of a group of two piezoelectric pressure sensors 5, and the other is composed of a group of two piezoelectric pressure sensors 6 for Monitor the sound pressure signals at different frequencies excited by the auxiliary pump 1 at the inlet and outlet pipelines of the test pump 2. The regulation and control system consists of three parts, one is the flow regulating valve Ⅰ7, the other is the waterway regulating valve group II～Ⅷ (8～14) connected in series and parallel in the oval dotted frame A, and the third is composed of the waterway regulating valve Ⅸ15 It is formed in parallel with the waterway regulating valve group Ⅹ～Ⅻ(16～18) in the oval dotted frame B, and the regulating control system is to regulate and control the external sound source or external acoustic impedance received by the test pump 2 through the following method: regulating the auxiliary pump 1 The variable frequency drive is used to change its speed, and then change the sound pressure amplitude and frequency of the auxiliary pump 1 as the sound source; control the opening of the flow regulating valve Ⅰ7 on the outlet pipeline of the auxiliary pump 1, that is, adjust the flow of the auxiliary pump 1, and then change Auxiliary pump 1 is used as the sound pressure amplitude of the sound source; adjust different waterway regulating valves Ⅱ～Ⅻ (8～18) on the branch pipeline between test pump 2 and auxiliary pump 1, so that the pipeline configuration has different acoustic impedance.

The outlet pipeline of the auxiliary pump 1 is provided with a flow regulating valve I7, and the outlet pipeline of the test pump 2 is provided with a waterway regulating valve IX15; between the auxiliary pump 1 and the test pump 2, the regulation control system includes a flow regulating valve I7 and an oval The first waterway regulating valve group in the dotted line box A; between the test pump 2 and the water tank 19, the regulation control system includes the waterway regulating valve IX15 and the second waterway regulating valve group in the oval dotted line box B.

The first regulating valve group in the oval dotted frame A is composed of waterway regulating valve Ⅱ8, waterway regulating valve Ⅲ9, waterway regulating valve Ⅳ10, waterway regulating valve Ⅴ11, waterway regulating valve Ⅵ12, waterway regulating valve Ⅶ13 and waterway regulating valve Ⅷ14 in series and parallel connection constitute. The second waterway regulating valve group in the elliptical dotted frame B is composed of waterway regulating valve X16, waterway regulating valve XI17 and waterway regulating valve XII18 connected in parallel.

The waterway system also includes circuits I, II, III, IV, V, VI, VII, VIII, IX, X, XI, and XII.

In loop I, the flow regulating valve I7, waterway regulating valve II8, waterway regulating valve III9, waterway regulating valve VI12, waterway regulating valve IX15, waterway regulating valve X16 are opened, and other waterway regulating valves are closed.

In circuit II, the flow regulating valve I7, waterway regulating valve II8, waterway regulating valve V11, waterway regulating valve VIII14, waterway regulating valve IX15, waterway regulating valve X16 are opened, and other waterway regulating valves are closed.

In circuit III, flow regulating valve I7, waterway regulating valve IV10, waterway regulating valve VII13, waterway regulating valve VIII14, waterway regulating valve IX15, waterway regulating valve X16 are opened, and other waterway regulating valves are closed.

In circuit IV, the flow control valve I7, the water channel control valve III9, the water channel control valve IV10, the water channel control valve V11, the water channel control valve VI12, the water channel control valve VII13, the water channel control valve IX15, the water channel control valve X16 are opened, and the other water channel control valves are closed.

Circuit Ⅴ is flow control valve Ⅰ7, water channel control valve Ⅱ8, water channel control valve Ⅲ9, water channel control valve Ⅵ12, water channel control valve Ⅸ15, water channel control valve Ⅺ17, and other water channel control valves are closed.

In circuit Ⅵ, flow regulating valve Ⅰ7, waterway regulating valve Ⅱ8, waterway regulating valve Ⅴ11, waterway regulating valve Ⅷ14, waterway regulating valve Ⅸ15, waterway regulating valve Ⅺ17 are opened, and other waterway regulating valves are closed.

In circuit VII, flow regulating valve I7, waterway regulating valve IV10, waterway regulating valve VII13, waterway regulating valve VIII14, waterway regulating valve IX15, waterway regulating valve Ⅺ17 are opened, and other waterway regulating valves are closed.

In loop VIII, the flow regulating valve I7, waterway regulating valve III9, waterway regulating valve IV10, waterway regulating valve V11, waterway regulating valve VI12, waterway regulating valve VII13, waterway regulating valve IX15, waterway regulating valve XI17 are opened, and the rest of the waterway regulating valves are closed.

In circuit Ⅸ, flow regulating valve Ⅰ7, waterway regulating valve Ⅱ8, waterway regulating valve Ⅲ9, waterway regulating valve Ⅵ12, waterway regulating valve Ⅸ15, waterway regulating valve Ⅻ18 are opened, and other waterway regulating valves are closed.

In circuit X, the flow control valve Ⅰ7, waterway control valve Ⅱ8, waterway control valve Ⅴ11, waterway control valve Ⅷ14, waterway control valve Ⅸ15, waterway control valve Ⅻ18 are opened, and other waterway control valves are closed.

In loop Ⅺ, flow regulating valve Ⅰ7, waterway regulating valve Ⅳ10, waterway regulating valve Ⅶ13, waterway regulating valve Ⅷ14, waterway regulating valve Ⅸ15, waterway regulating valve Ⅻ18 are opened, and other waterway regulating valves are closed.

In loop Ⅻ, flow regulating valve Ⅰ7, waterway regulating valve Ⅲ9, waterway regulating valve Ⅳ10, waterway regulating valve Ⅴ11, waterway regulating valve Ⅵ12, waterway regulating valve Ⅶ13, waterway regulating valve Ⅸ15, waterway regulating valve Ⅻ18 are opened, and other waterway regulating valves are closed.

The waterway system also includes closing the waterway regulating valves IX15 in circuits I, II, III, IV, V, VI, VII, VIII, IX, X, XI, and XII, and keeping the other regulating valves unchanged.

When the test bench conducts the acoustic transmission characteristic test of the vane pump port at different frequencies, without changing the pipeline, through the adjustment of the auxiliary pump 1 variable frequency drive, the adjustment of the opening of the flow control valve I7 and the adjustment of different waterway control valves on the branch pipelines The mutual cooperation of Ⅱ8～Ⅻ18 can complete the relevant test, and the following part of the specific implementation process will be explained:

The first test process: during the test, the waterway system selects circuit I, the test pump 2 is in a static state, the auxiliary pump 1 is running at a certain speed, and only the opening of the flow regulating valve I7 is adjusted, and then the auxiliary pump 1 is used as the sound source. The intensity of the source changes, so that the auxiliary pump 1 operates as a sound source under different flow conditions, and the difference measured by the piezoelectric pressure sensor group 5 and the piezoelectric pressure sensor group 6 on the inlet and outlet pipelines of the test pump 2 can be obtained. Sound pressure magnitude results.

The second test process: refer to the first test process above, the difference is that only the selection scheme of the water system circuit during the test is changed at this time, such as the circuit Ⅱ～Ⅻ, that is, the acoustic impedance of the external water system of the test pump 2 is changed, and the other conditions remain unchanged. , it can be obtained that under each waterway system loop scheme, when the auxiliary pump 1 is used as the sound source and operates under different flow conditions, the measured values of the piezoelectric pressure sensor 5 and the piezoelectric pressure sensor 6 on the inlet and outlet pipelines of the test pump 2 The results of different sound pressure amplitudes.

The third test process: refer to the first test process above, the difference is that the flow regulating valve Ⅰ7 maintains a certain opening degree at this time, and only the speed of the auxiliary pump 1 is adjusted through the variable frequency drive, and then the sound source intensity and sound intensity of the auxiliary pump 1 as the sound source The frequency of the source changes, so that the auxiliary pump 1 can be used as the sound source to run at different speeds and frequencies, and the measured results of the piezoelectric pressure sensor group 5 and the piezoelectric pressure sensor group 6 on the inlet and outlet pipelines of the test pump 2 are obtained. Results for different sound pressure amplitudes.

The fourth test process: similarly, close the waterway regulating valve Ⅸ15 in the circuit Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ, Ⅵ, Ⅶ, Ⅷ, Ⅸ, Ⅹ, Ⅺ, Ⅻ, and keep the other regulating valves unchanged, and complete the test respectively The above-mentioned first test process, second test process and third test process.

Calculation process: According to the above-mentioned first test process, the second test process, the third test process and the fourth test process, the different sound pressure amplitudes measured by the piezoelectric pressure sensor 5 on the test pump 2 inlet pipeline are listed as follows equation:

Δl _up =x ₂ -x ₁ (3)

where p _1,up (x,t) and p _2up (x,t) represent the sound pressure amplitudes measured by the two piezoelectric pressure sensors on the inlet pipeline of test pump 2 respectively; The amplitude of the plane sound pressure propagating in the forward and reverse directions in the road, and the phase of the respective plane sound pressure, where the forward direction refers to the direction of sound pressure wave propagation pointing to the inlet direction of the pump, and the reverse direction refers to the sound pressure The direction of wave propagation is away from the inlet of the pump; x ₁ and x ₂ are the distances from the two piezoelectric pressure sensors in the piezoelectric pressure sensor group 5 to the inlet of the test pump 2; The distance between two piezoelectric pressure sensors; is the imaginary unit, ω=2πf represents the angular frequency, f represents the frequency, represents the wave number, and is the speed of sound in the medium. According to equations (1) ~ (3) to solve to get:

Similarly, according to the different sound pressure amplitudes measured by the piezoelectric pressure sensor group 6 on the outlet pipeline of the test pump 2 in the above-mentioned first test process, second test process, third test process and fourth test process, list The following equation:

Δl _down = x ₄ -x ₃ (8)

where p _1,down (x,t) and p _2,down (x,t) represent the sound pressure amplitudes measured by the two piezoelectric pressure sensors in the piezoelectric pressure sensor group 6 on the outlet pipeline of the test pump 2 respectively value; and represent respectively the amplitude of the plane sound pressure propagating in positive and negative directions in the outlet pipeline of the test pump 2, and the phase of the plane sound pressure respectively, wherein the positive direction propagation refers to the sound pressure wave propagation direction pointing to the outlet of the pump direction, the opposite direction of propagation refers to the sound pressure wave propagation direction facing away from the outlet of the pump; _x3 and _x4 are the distances from the two piezoelectric pressure sensors in the piezoelectric pressure sensor group 6 to the outlet of the test pump 2 respectively; Indicates the distance between two piezoelectric pressure sensors in the piezoelectric pressure sensor group 6 . According to equations (6) ~ (8) to solve:

和

列出如下方程组：n data sets obtained by solving equations (1)～(3) and (6)～(8)

and

List the following equations:

The overdetermined equations (11) and (12) can be solved by the least square method, and the inlet reflection coefficient S ₁₁ , the inlet transmission coefficient S ₁₂ , the outlet reflection coefficient S ₂₂ , and the outlet transmission coefficient S ₂₁ of the test pump 2 are obtained. , which is the port acoustic transmission characteristic parameter of test pump 2.

The above description is only a preferred embodiment of the present invention, and for those skilled in the art, any improvement to the present invention without any creative work belongs to the protection scope of the present invention.

Claims (6)

1. A test bench for testing the acoustic transmission characteristics of a vane pump port, characterized in that it includes an auxiliary pump, a test pump, a flow meter, a flow regulating valve I, waterway regulating valves II～Ⅻ, a water tank and a waterway system thereof; The pump and the test pump are connected through pipelines, and the auxiliary pump and the test pump are connected to the water tank through pipelines to form the main circuit of the water circulation system; flow meters are installed on the outlet pipelines of the auxiliary pump and the test pump; The test bench can be divided into a monitoring system and an adjustment control system; the monitoring system is composed of two groups of four piezoelectric pressure sensors, which are respectively located on the inlet pipeline and outlet pipeline of the test pump, and each group includes two pressure sensors. The electric pressure sensor is used to monitor the sound pressure signals at different frequencies excited by the auxiliary pump at the inlet pipeline and the outlet pipeline of the test pump; the adjustment control system includes the first water circuit between the auxiliary pump and the test pump Regulating valve group and flow regulating valve Ⅰ on the outlet pipeline of the auxiliary pump, the second waterway regulating valve group between the test pump and the water tank and waterway regulating valve Ⅸ on the outlet pipeline of the test pump; the regulation The control system adjusts the external sound source or external acoustic impedance received by the test pump; the first waterway regulating valve group includes waterway regulating valve IV, waterway regulating valve V and waterway regulating valve VI, waterway regulating valve IV and waterway regulating valve set in parallel The two sides of valve V are respectively connected in series with waterway regulating valve II and waterway regulating valve VII, and the two sides of waterway regulating valve V and waterway regulating valve VI are respectively connected in series with waterway regulating valve III and waterway regulating valve VIII; the second waterway regulating valve The group includes waterway regulating valve Ⅹ, waterway regulating valve Ⅺ and waterway regulating valve Ⅻ arranged in parallel. 2. A test bench for testing the acoustic transmission characteristics of a vane pump port according to claim 1, wherein the adjustment step of the adjustment system includes: adjusting the variable frequency drive of the auxiliary pump to change its speed, and then changing the auxiliary pump The sound pressure amplitude and frequency of the pump as the sound source; control the opening of the flow regulating valve I on the outlet pipeline of the auxiliary pump, and then change the sound pressure amplitude of the auxiliary pump as the sound source; adjust the pressure on the branch pipeline between the test pump and the auxiliary pump. Different waterway regulating valves Ⅱ～Ⅻ make the pipeline configuration have different acoustic impedance. 3. A test bench for testing the acoustic transmission characteristics of a vane pump port as claimed in claim 2, wherein said adjustment step comprises a first test process, a second test process, a third test process, and a fourth test process and calculation process; The first test process: during the test, the waterway system selects circuit Ⅰ, the test pump is in a static state, the auxiliary pump is running at a preset speed, and the opening of the flow regulating valve Ⅰ is adjusted, so that the sound source intensity of the auxiliary pump as a sound source changes. , so as to obtain the results of different sound pressure amplitudes measured by the piezoelectric pressure sensor group and the piezoelectric pressure sensor group on the inlet and outlet pipelines of the test pump under different flow conditions when the auxiliary pump is used as the sound source; The second test process: on the basis of the first test process, change the selection scheme of the waterway system circuit during the test, select the circuit Ⅱ～Ⅻ, change the acoustic impedance of the external waterway system of the test pump, and keep the other conditions unchanged. Under a waterway system circuit scheme, when the auxiliary pump is used as the sound source and operates under different flow conditions, test the results of different sound pressure amplitudes measured by the piezoelectric pressure sensor on the pump inlet and outlet pipelines and the piezoelectric pressure sensor; The third test process: On the basis of the first test process, keep the flow regulating valve I at the preset opening, adjust the speed of the auxiliary pump through the variable frequency drive, and then the sound source intensity and frequency of the sound source of the auxiliary pump will change , so as to obtain the results of different sound pressure amplitudes measured by the piezoelectric pressure sensor group and the piezoelectric pressure sensor group on the inlet and outlet pipelines of the test pump when the auxiliary pump is used as the sound source at different speeds and different frequencies; The fourth test process: on the basis of the first test process, the waterway regulating valve Ⅸ in the circuit Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ, Ⅵ, Ⅶ, Ⅷ, Ⅸ, Ⅹ, Ⅺ, Ⅻ is closed, and the remaining control valves Keep unchanged, complete the first experimental process, the second experimental process, and the third experimental process respectively; Calculation process: Calculate the port of the test pump according to the different sound pressure amplitudes measured by the piezoelectric pressure sensor group on the inlet pipeline of the test pump in the first experiment process, the second experiment process, the third experiment process and the fourth experiment process Acoustic transmission characteristic parameters. 4. A test bench for testing the acoustic transmission characteristics of a vane pump port as claimed in claim 3, wherein the acoustic transmission characteristic parameters of the test pump port include the inlet reflection coefficient S ₁₁ and the inlet transmission coefficient S of the test pump. _12. Reflection coefficient S ₂₂ at the exit end, transmission coefficient S ₂₁ at the exit end. 5. A kind of test bench for testing the acoustic transmission characteristics of the vane pump port as claimed in claim 3, wherein the calculation process comprises: according to the first experimental process, the second experimental process, the third experimental process, the fourth During the experiment, the different sound pressure amplitudes measured by the piezoelectric pressure sensor group on the inlet pipeline of the test pump are listed as follows:

Δl _up =x ₂ -x ₁ (3) Where p _1,up (x,t) and p _2up (x,t) respectively represent the sound pressure amplitudes measured by the two piezoelectric pressure sensors in the piezoelectric pressure sensor group on the inlet pipeline of the test pump;

and

Respectively represent the plane sound pressure amplitudes propagating in the forward and reverse directions in the inlet pipeline of the test pump,

and

Respectively, the phase of the plane sound pressure, where the positive direction propagation means that the sound pressure wave propagation direction points to the pump inlet direction, and the reverse direction propagation means that the sound pressure wave propagation direction is away from the pump inlet direction; x ₁ and x ₂ are the pressure The distance between the two piezoelectric pressure sensors in the electric pressure sensor group and the inlet end of the test pump; Δl _up represents the distance between the two piezoelectric pressure sensors in the piezoelectric pressure sensor group;

is an imaginary number unit, ω=2πf represents the angular frequency, f represents the frequency, k=ω/c ₀ represents the wave number, and c ₀ is the speed of sound in the medium; according to equations (1)～(3), it is obtained by solving:

According to the different sound pressure amplitudes measured by the piezoelectric pressure sensor group on the outlet pipeline of the test pump in the first test process, the second test process, the third test process and the fourth test process, the following equations are listed:

Δl _down = x ₄ -x ₃ (8) Where p _1,down (x,t) and p _1,down (x,t) represent the sound pressure amplitudes measured by the two piezoelectric pressure sensors in the piezoelectric pressure sensor group on the outlet pipeline of the test pump respectively;

and

Respectively represent the plane sound pressure amplitudes propagating in the forward and reverse directions in the outlet pipeline of the test pump,

and

Respectively, the phase of the plane sound pressure, where the positive direction propagation refers to the sound pressure wave propagation direction pointing to the pump outlet direction, and the reverse direction propagation refers to the sound pressure wave propagation direction facing away from the pump outlet direction; x3 and x4 are piezoelectric The distance between the two piezoelectric pressure sensors in the pressure sensor group and the outlet of the test pump; Δl _down represents the distance between the two piezoelectric pressure sensors in the piezoelectric pressure sensor group; according to equations (6)-(8) Solve to get:

n data sets obtained by solving equations (1)～(3) and (6)～(8)

and

List the following equations:

The overdetermined equations (11) and (12) can be solved by the least square method, and the inlet reflection coefficient S ₁₁ , inlet transmission coefficient S ₁₂ , outlet reflection coefficient S ₂₂ , and outlet transmission coefficient S ₂₁ of the test pump can be obtained. 6. A kind of test bench for testing the acoustic transmission characteristics of the vane pump port as claimed in claim 1, wherein the distance between the two piezoelectric pressure sensors in each group at the inlet pipeline place and the outlet pipeline place is 10 to 20 times the inner diameter of the pipe.

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