A transonic wind tunnel Mach number control stationary air extraction system and air extraction method

Abstract

The present invention relates to a transonic wind tunnel Mach number controlled resident chamber exhaust system and exhaust method, belonging to the field of wind tunnel construction and operation technology. The system solves the problem of limited simulation range of transonic flow field operation conditions. The main circuit includes a main compressor, a cavity circuit, a resident chamber section and a reentry section. The main compressor, the cavity circuit and the resident chamber section are connected in a circular manner in sequence. The exhaust circuit includes a resident chamber exhaust compressor, a first pipeline, an inlet valve, an outlet valve, a valve, a pipeline and a second pipeline. The first pipeline, the resident chamber exhaust compressor and the second pipeline are connected in sequence. An inlet valve is provided on the inlet side of the first pipeline, the first pipeline is connected to the resident chamber section, an outlet valve is provided on the outlet side of the second pipeline, the second pipeline is connected to the reentry section, the outlet side of the first pipeline and the inlet side of the second pipeline are connected by a pipeline, and a valve is provided on the pipeline. The present invention realizes operation under negative pressure, normal pressure and supercharged pressure conditions in a continuous transonic wind tunnel, greatly expanding the simulation range of wind tunnel operation.

Description

Technical Field

[0001] The invention relates to a wind tunnel resident chamber air extraction system and method, belonging to the technical field of wind tunnel construction and operation. Background Art

[0002] Wind tunnel testing, a widely used method in aerodynamic research, provides essential support for the development of fields such as aviation, aerospace, and rail transportation. In a continuous transonic wind tunnel, a main compressor unit is located within the tunnel circuit to drive air flow within the circuit and provide the operating pressure ratio required to establish the wind tunnel flow field. A stagnation chamber extraction system extracts a portion of the air from the stagnation chamber at transonic speeds (Mach number range 0.8 ≤ M ≤ 1.2) and supersonic speeds (Mach number range 1.2 < M ≤ 1.6) to cooperate with the main compressor to establish the wind tunnel test flow field. During the subsonic phase of the wind tunnel test, where Mach numbers are less than 0.8, only the main compressor is used. During the transonic phase, where Mach numbers are 0.8 ≤ M ≤ 1.6, or when the test model has a high degree of obstruction, the main compressor alone cannot achieve the required test Mach number. Therefore, a stagnation chamber extraction system is required to cooperate with the main compressor to establish the wind tunnel test flow field.

[0003] The relevant tests in "Study on Chambered Exhaust Compressors and Their Correlation with Wind Tunnel Performance" disclosed the impact of the operating efficiency and exhaust volume of the chambered exhaust compressor unit on the root mean square deviation of the Mach number in the wind tunnel test section, but did not propose the coordinated use of the chambered exhaust system and the main compressor, nor how to achieve transonic flow field control.

[0004] The "Ejector-driven, closed-loop, recirculating, transient supersonic wind tunnel flow field control method" discloses that the ejector after the diffuser section is used as the main drive of the wind tunnel flow field. With the cooperation of the reflow regulating valve, the auxiliary intake pressure regulating valve, and the exhaust throttle valve, a stable supersonic flow field is established. The simulation of negative pressure operating conditions can be achieved in a closed-loop, recirculating, transient supersonic wind tunnel. However, the simulation of its operating conditions under normal pressure and boosted pressure conditions is not proposed, and the simulation range is limited.

[0005] Based on the above problems, it is urgent to propose a transonic wind tunnel Mach number controlled resident air extraction system and air extraction method to solve the above technical problems. Summary of the Invention

[0006] The present invention provides a transonic wind tunnel Mach number-controlled resident air extraction system and method, addressing the limited simulation range of transonic flow field operating conditions. A brief overview of the invention is provided below to provide a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive overview of the invention. It is not intended to identify key or important aspects of the invention, nor is it intended to limit the scope of the invention.

[0007] The technical solution of the present invention:

[0008] A transonic wind tunnel Mach number-controlled resident air extraction system comprises a main circuit comprising a main compressor, a tunnel circuit, a resident section and a reentry section, wherein the main compressor, the tunnel circuit, the resident section and the reentry section are connected in a circular sequence, and the air extraction circuit comprises a resident air extraction compressor, a first pipeline, an inlet valve, an outlet valve, a valve, a pipeline and a second pipeline, wherein the first pipeline, the resident air extraction compressor and the second pipeline are connected in sequence, an inlet valve is provided on the inlet side of the first pipeline, and the inlet end of the first pipeline is connected to the resident section, an outlet valve is provided on the outlet side of the second pipeline, and the outlet end of the second pipeline is connected to the reentry section, the outlet side of the first pipeline and the inlet side of the second pipeline are connected via a pipeline, and valves are provided on the pipelines.

[0009] Preferably, the main motor is connected to the main compressor, and the stationary air extraction motor is connected to the stationary air extraction compressor.

[0010] Preferably: the inlet valve and the outlet valve are both regulating valves, and the valves are quick-opening butterfly valves.

[0011] Preferably, a stabilization section, a contraction section, a nozzle section, a test section, a diffusion section, and a reentry section are sequentially connected in the chamber section, the cave loop is connected to the stabilization section, the reentry section is connected to the main compressor, and slots or holes are provided on the four side walls of the test section, through which the airflow in the test section can enter the chamber section.

[0012] A transonic wind tunnel Mach number controlled resident chamber exhaust method, the method being implemented using a transonic wind tunnel Mach number controlled resident chamber exhaust system, comprising the following steps:

[0013] Step 1: Start the main compressor; close the inlet valve and outlet valve, open the valve, and start the indoor exhaust compressor.

[0014] Step 2: Open the inlet valve and outlet valve in sequence, close the valves, and increase the speed of the main compressor.

[0015] Step 3: Open the valve, close the outlet valve and the inlet valve in sequence, and the resident exhaust compressor runs independently at the test operating speed in the exhaust circuit, waiting to be cut into the main circuit when the test is required, or the resident exhaust compressor is reduced to a low speed for cranking operation; the main compressor continues to carry out subsonic or transonic tests in the main circuit.

[0016] Preferably: in step 1, the main compressor is operated at the lowest speed, and the speed of the stationary exhaust compressor is adjusted to the operating speed;

[0017] In step 2, the rotation speed of the main compressor is increased to the Mach number required by the test;

[0018] In step three, the main compressor conducts a subsonic test with a Mach number below 0.8 or a transonic test with a small degree of blockage of the test piece in the main circuit.

[0019] The present invention has the following beneficial effects:

[0020] The present invention enables the resident chamber exhaust system to be quickly put into the main circuit and cooperate with the main compressor to establish a transonic test flow field. Its piping system can meet the requirements of the resident chamber exhaust compressor to carry out aerodynamic performance tests such as surge boundary testing.

[0021] The present invention can realize operation under negative pressure, normal pressure, and supercharged pressure in a continuous transonic wind tunnel, greatly expanding the wind tunnel operation envelope and simulation range;

[0022] The present invention can quickly cut the exhaust circuit into the main circuit, reduce the waiting time of the wind tunnel test, and improve the test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural diagram of a stationary air extraction system for Mach number control in a transonic wind tunnel;

[0024] Figure 2 yes Figure 1 Middle AA section view;

[0025] Figure 3 This is a flow chart of the exhaust operation of a stationary exhaust system for Mach number control in a transonic wind tunnel;

[0026] Figure 4 It is a flow chart of the independent operation of the resident chamber exhaust system for Mach number control of a transonic wind tunnel;

[0027] Figure 5 The present invention is a flow chart of a stationary air extraction method for Mach number control in a transonic wind tunnel.

[0028] In the figure: 1-main compressor, 2-main motor, 3-cavity loop, 4-stable section, 5-contraction section, 6-nozzle section, 7-test section, 8-stationary section, 9-diffusion section, 10-reentry section, 11-stationary chamber exhaust compressor, 12-stationary chamber exhaust motor, 13-first pipeline, 14-inlet valve, 15-outlet valve, 16-valve, 17-pipeline, 18-second pipeline. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of the present invention more clearly apparent, the present invention is described below using specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely illustrative and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0030] The connections mentioned in the present invention are divided into fixed connections and detachable connections. The fixed connection refers to a non-detachable connection, including but not limited to conventional fixed connection methods such as hem connection, rivet connection, adhesive connection, and welding connection. The detachable connection refers to but not limited to conventional detachable connection methods such as threaded connection, snap connection, pin connection, and hinge connection. When the specific connection method is not clearly specified, it is assumed that at least one connection method can always be found among the existing connection methods to achieve the function. Those skilled in the art can choose according to their needs. For example, a welded connection is selected for a fixed connection, and a hinge connection is selected for a detachable connection.

[0031] Specific implementation method 1: Combination Figure 1-Figure 4 The present embodiment is described. The present embodiment is a transonic wind tunnel Mach number controlled resident chamber exhaust system, comprising a main circuit and an exhaust circuit. The main circuit comprises a main compressor 1, a tunnel circuit 3, a resident chamber section 8 and a reentry section 10. The main compressor 1, the tunnel circuit 3 and the resident chamber section 4 are connected in a circular manner. The reentry section 10 is installed with the resident chamber section 8, allowing the wind tunnel to operate under pressurized, normal pressure and negative pressure conditions, which can greatly expand the wind tunnel test operation envelope and simulation range. The exhaust circuit comprises a resident chamber exhaust compressor 11, a first pipeline 13, an inlet valve 14, outlet valve 15, valve 16, pipeline 17 and second pipeline 18, the second pipeline 18, the chamber exhaust compressor 11, and the first pipeline 13 are connected in sequence; an inlet valve 14 is provided on the inlet side of the first pipeline 13, and the inlet end of the first pipeline 13 is connected to the chamber section 8 through two upper and lower air inlets, an outlet valve 15 is provided on the outlet side of the second pipeline 18, and the outlet end of the second pipeline 18 is connected to the reentry section 10, the outlet side of the first pipeline 13 and the inlet side of the second pipeline 18 are connected through the pipeline 17, and the valve 16 is provided on the pipeline 17.

[0032] The main motor 2 is connected to the shaft system of the main compressor 1, and the resident chamber exhaust motor 12 is connected to the shaft system of the resident chamber exhaust compressor 11; the operating speed of the main compressor 1 and the resident chamber exhaust compressor 11 can be adjusted by adjusting the speed of the main motor 2 and the resident chamber exhaust motor 12 by frequency conversion. The main motor 2 and the resident chamber exhaust motor 12 are variable frequency speed regulation motors. During the wind tunnel test, the compressor can be controlled to slowly increase or decrease speed and slowly change the wind tunnel test Mach number. By adjusting the opening of the pressure regulating valve to adjust the test flow field, the impact load on the model during the establishment or closing process of the Mach number flow field can be greatly reduced; by adjusting the speed of the resident chamber exhaust motor 12, the air flow rate extracted from the resident chamber section 8 by the exhaust circuit and the induced effect on the air flow in the test section 7 can be controlled, and then the test Mach number can be controlled in cooperation with the main compressor 1.

[0033] The inlet valve 14 and the outlet valve 15 are both regulating valves, and the valve 16 is a quick-opening butterfly valve.

[0034] The stabilizing section 4, the contracting section 5, the nozzle section 6, the test section 7, the diffuser section 9, and the reentry section 10 connected in sequence are located inside the stationary section 8. The tunnel loop 3 is connected to the protruding end of the stabilizing section 4, and the protruding end of the reentry section 10 is connected to the main compressor 1. During the wind tunnel test, the airflow flows in the stabilizing section 4, the contracting section 5, the nozzle section 6, the test section 7, the diffuser section 9, and the reentry section 10. The four side walls of the test section 7 are provided with slots or holes. The airflow in the test section 7 can enter the stationary section 8 through the slots or holes. When the stationary section exhaust system is used to test the Mach number, the stationary section 8 The chamber exhaust compressor 11 extracts part of the air flow in the test section 7 through the stationary section 8 through the first pipeline 13, forming an induced effect on the main air flow in the test section 7, and participating in the Mach number control in the test section 7. When the exhaust circuit is used, the inlet valve 14 and the outlet valve 15 are opened, and the valve 16 is closed. The exhaust circuit extracts air from the stationary section 8, forming an induced effect on the air flow in the test section 7, accelerating the air flow in the test section 7 to achieve the required Mach number. The extracted air flow finally returns to the main circuit from the re-entry section 10 to ensure that the air volume in the main circuit of the wind tunnel is constant.

[0035] Specific implementation method 2: Combination Figure 1-Figure 5 The present embodiment is described. The present embodiment is a transonic wind tunnel Mach number controlled resident chamber exhaust method. The method is implemented by a transonic wind tunnel Mach number controlled resident chamber exhaust system, including a main circuit and an exhaust circuit. The main circuit includes a main compressor 1, a cavity circuit 3, a stabilizing section 4, a contracting section 5, a nozzle section 6, a test section 7, a resident chamber section 8, a diffuser section 9 and a reentry section 10. The main compressor 1, the cavity circuit 3, and the resident chamber section 4 are connected in a circular sequence. The stabilizing section 4, the contracting section 5, the nozzle section 6, the test section 7, the diffuser section 9 and the reentry section 10 are located inside the resident chamber section 8. The exhaust circuit includes The chamber exhaust compressor 11, the first pipeline 13, the inlet valve 14, the outlet valve 15, the valve 16, the pipeline 17 and the second pipeline 18, the first pipeline 13, the chamber exhaust compressor 11, and the second pipeline 18 are connected in sequence, the inlet valve 14 is set on the inlet side of the first pipeline 13, the inlet end of the first pipeline 13 is connected to the chamber section 8 through the upper and lower air inlets, the outlet valve 15 is set on the outlet side of the second pipeline 18, the outlet end of the second pipeline 18 is connected to the re-entry section 10, the outlet side of the first pipeline 13 and the inlet side of the second pipeline 18 are connected through the pipeline 17, and the valve 16 is set on the pipeline 17.

[0036] The main motor 2 is connected to the shaft system of the main compressor 1, and the resident air extraction motor 12 is connected to the shaft system of the resident air extraction compressor 11.

[0037] The inlet valve 14 and the outlet valve 15 are both regulating valves, and the valve 16 is a quick-opening butterfly valve.

[0038] The stabilizing section 4, the contracting section 5, the nozzle section 6, the test section 7, the diffusion section 9, and the reentry section 10 are located inside the stationary section 8. During the wind tunnel test, the airflow flows in the stabilizing section 4, the contracting section 5, the nozzle section 6, the test section 7, the diffusion section 9, and the reentry section 10. The four side wall panels of the test section 7 are provided with slots or holes, and the airflow in the test section 7 can enter the stationary section 8 through the slots or holes; the slots or holes in the wall panels of the test section 7 can allow the stationary exhaust compressor 11 to extract part of the airflow in the test section 7 through the stationary section 8 through the first pipeline 13 when the stationary exhaust system is used to participate in Mach number control, thereby forming an induced effect on the main airflow in the test section 7, participating in the Mach number control in the test section 7, and this part of the airflow eventually returns to the reentry section 10 through the second pipeline 18.

[0039] The present invention enables the resident air extraction system to be quickly put into the main circuit and cooperate with the main compressor to establish a transonic test flow field. Its piping system can meet the needs of the resident air extraction compressor to carry out aerodynamic performance tests such as surge boundary testing; the present invention can operate under negative pressure, normal pressure, and boost pressure conditions in a continuous transonic wind tunnel, greatly expanding the wind tunnel operation envelope and simulation range.

[0040] The following steps are involved:

[0041] Step 1: Start the main motor 2 to drive the main compressor 1 to run; close the inlet valve 14 and the outlet valve 15, open the valve 16, and simultaneously start the resident exhaust motor 8 to drive the resident exhaust compressor 7 to run;

[0042] In step 1, the main compressor 1 is operated at the lowest speed, and the speed of the chamber exhaust compressor 11 is adjusted to the required operating speed. The operating speed is related to the air extraction amount in the chamber section 8 and can be adjusted according to the actual Mach number requirement. Changing the speed of the chamber exhaust compressor 11 can adjust the air extraction amount in the chamber section 8, thereby generating different airflow injection effects on the main airflow in the test section 7, and cooperating with the main compressor 1 to control the test Mach number in the test section 7 to achieve the required Mach number;

[0043] Step 2: Open the inlet valve 14 and the outlet valve 15 in sequence, cut the exhaust circuit into the main circuit, slowly close the valve 16, and the chamber exhaust compressor 11 is gradually loaded and no longer backflows. The exhaust volume is all from the chamber section 8, forming an induced effect on the airflow in the test section 7, thereby increasing the Mach number of the airflow in the test section 7;

[0044] In step 2, the rotation speed of the main compressor 1 is increased to the Mach number required by the test;

[0045] Step 3: After the exhaust circuit is used up, open valve 16 and close outlet valve 15 and inlet valve 14. This operation will disconnect the resident exhaust system from the wind tunnel main circuit, and it will no longer participate in the test Mach number control. The resident exhaust compressor 11 will run independently at the test operating speed in the exhaust circuit, waiting to be cut into the main circuit when the test is needed, or the resident exhaust compressor 11 will be reduced to a low speed for cranking operation. The main compressor 1 will continue to carry out subsonic or transonic tests in the main circuit.

[0046] In step 3, the main compressor 1 is subjected to a subsonic test with a Mach number below 0.8 or a transonic or supersonic test with a small degree of blockage of the test piece in the main circuit.

[0047] The exhaust circuit can be quickly cut into the main circuit, reducing the waiting time of wind tunnel tests and improving test efficiency.

[0048] The present invention utilizes a resident exhaust compressor 11 with precisely adjustable speed in conjunction with a main compressor 1 to control the test Mach number. By controlling the speed of the resident exhaust compressor, the exhaust volume is precisely controlled to achieve a test Mach number of 1.6 or below. The application method of controlling the wind tunnel Mach number by using the resident exhaust compressor in conjunction with the main compressor can greatly improve the test efficiency of the resident exhaust system operation mode in a continuous transonic wind tunnel.

[0049] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be permuted and combined. Those skilled in the art can exhaust all possibilities based on the mathematical knowledge of permutations and combinations. Therefore, the present invention will no longer describe the technical solutions after permutations and combinations one by one, but it should be understood that the technical solutions after permutations and combinations have been disclosed by the present invention.

[0050] This embodiment is only an illustrative description of this patent and does not limit its scope of protection. Those skilled in the art may also make partial changes to it. As long as it does not exceed the spirit of this patent, it is within the scope of protection of this patent.

Claims

1. A transonic wind tunnel Mach number control stationary air extraction system, characterized by: The invention comprises a main circuit and an exhaust circuit, wherein the main circuit comprises a main compressor (1), a cavity circuit (3), a chamber section (8) and a reentry section (10), wherein the main compressor (1), the cavity circuit (3) and the chamber section (8) are connected in a circular manner, and the exhaust circuit comprises a chamber exhaust compressor (11), a first pipeline (13), an inlet valve (14), an outlet valve (15), a valve (16), a pipeline (17) and a second pipeline (18), wherein the first pipeline (13), the chamber exhaust compressor (11), the second The pipelines (18) are connected in sequence, an inlet valve (14) is provided on the inlet side of the first pipeline (13), the inlet end of the first pipeline (13) is connected to the stationary section (8), an outlet valve (15) is provided on the outlet side of the second pipeline (18), the reentry section (10) is installed with the stationary section (8), the outlet end of the second pipeline (18) is connected to the reentry section (10), the outlet side of the first pipeline (13) and the inlet side of the second pipeline (18) are connected through the pipeline (17), and a valve (16) is provided on the pipeline (17).

2. The transonic wind tunnel Mach number control stationary air extraction system according to claim 1, characterized in that: The main motor (2) is connected to the main compressor (1), and the stationary air extraction motor (12) is connected to the stationary air extraction compressor (11).

3. The transonic wind tunnel Mach number control stationary air extraction system according to claim 2, characterized in that: The inlet valve (14) and the outlet valve (15) are both regulating valves, and the valve (16) is a quick-opening butterfly valve.

4. The transonic wind tunnel Mach number control stationary air extraction system according to claim 3, characterized in that: The stationary section (8) is provided with a stabilizing section (4), a contracting section (5), a nozzle section (6), a test section (7), a diffusion section (9), and a reentry section (10) which are connected in sequence. The cavity loop (3) is connected to the stabilizing section (4), and the reentry section (10) is connected to the main compressor (1). Slots or holes are provided on the four sidewalls of the test section (7), and the airflow in the test section (7) can enter the stationary section (8) through the slots or holes.

5. A transonic wind tunnel Mach number control stationary air extraction method, characterized by: The method is implemented using a transonic wind tunnel Mach number control stationary air extraction system as described in claim 4, comprising the following steps: Step 1: Start the main compressor (1); close the inlet valve (14) and the outlet valve (15), open the valve (16), and start the resident air extraction compressor (11); Step 2: Open the inlet valve (14) and the outlet valve (15) in sequence, close the valve (16), and increase the speed of the main compressor (1); Step 3: Open the valve (16), close the outlet valve (15) and the inlet valve (14) in sequence, and the resident exhaust compressor (11) operates independently at the test operating speed in the exhaust circuit, waiting to be cut into the main circuit when the test is required, or the resident exhaust compressor (11) is reduced to a low speed for cranking operation; the main compressor (1) continues to carry out subsonic test or transonic test in the main circuit.

6. The method for evacuating a transonic wind tunnel Mach number according to claim 5, characterized in that: In step 1, the main compressor (1) is operated at the lowest speed, and the speed of the resident exhaust compressor (11) is adjusted to the operating speed; In step 2, the rotation speed of the main compressor (1) is increased to the Mach number required by the test; In step 3, the main compressor (1) is subjected to a subsonic test with a Mach number below 0.8 or a transonic test with a small blockage degree of the test piece in the main circuit.

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