Test bed for testing performance and flow schlieren of cold flow binary supersonic speed separation line spray pipe

Abstract

The invention discloses a test bed for testing the performance and flow schlieren of a cold-flow binary supersonic separation line nozzle. The test bed comprises a supporting structure, an air supply structure, a servo actuation system and a supersonic separation line nozzle, the supporting structure comprises a base and a thrust frame, and a spray pipe supporting frame and an air inlet section supporting frame are installed on the base. The air supply structure comprises an air inlet section, a transition section and a connecting section which are sequentially connected through flanges, the front end of the air inlet section is connected with the thrust frame, and the lower portion of the air inlet section is supported by the air inlet section supporting frame. According to the invention, the working process of the supersonic separation line nozzle at different swing angles and different swing speeds can be reproduced under the ground experiment condition, and the flow state and wall surface pressure distribution characteristics of the two-dimensional nozzle are respectively obtained through the schlieren system and the pressure sensor; the device is used for testing the working state of the supersonic separation line nozzle under the condition of high-pressure cold flow nitrogen input, and has the advantages of high adaptability and accurate measurement.

Description

Technical Field

[0001] The present invention belongs to the field of nozzle test runs and tests in aerospace test technologies, and particularly relates to a cold flow two-dimensional supersonic separation line nozzle performance and flow schlieren test run platform. Background Art

[0002] A supersonic separation line nozzle is a swing nozzle capable of achieving a thrust vector effect, having advantages such as a large deflection angle, light structural mass, and good sealing performance, and can provide good thrust vector performance for a vehicle. A supersonic separation line nozzle generally consists of a fixed section, a movable section, a connecting piece, and an actuating mechanism. By controlling the swing of the movable section of the nozzle, the direction of the deflected airflow is changed to achieve the thrust vector effect. During the swing of the movable section of the nozzle, complex flow phenomena are accompanied, including characteristics such as shock wave reflection on the solid wall, shock wave-shock wave interaction, and flow separation. This poses certain challenges to the profile design and performance improvement of the supersonic separation line nozzle. Revealing the internal flow evolution law during the working process of the supersonic separation line nozzle and exploring the influencing mechanism of the thrust vector characteristics of the supersonic separation line nozzle are crucial for the profile design and performance improvement of the supersonic separation line nozzle.

[0003] Existing experimental devices for supersonic separation line swing nozzles have certain limitations in experimental research, mainly manifested as the inability to achieve real-time observation of the flow field while swinging, which not only limits the in-depth analysis of the flow characteristics of the nozzle but also reduces the acquisition efficiency of experimental data. In addition, the process of replacing the nozzle profile of traditional devices is relatively complex and difficult to meet the rapid adjustment requirements under various working conditions. Summary of the Invention

[0004] The purpose of the present invention is to provide a cold flow two-dimensional supersonic separation line nozzle performance and flow schlieren test run platform, which can reproduce the working state of the supersonic separation line nozzle at different swing angles under ground experimental conditions, realize and observe the swing process of the supersonic separation line nozzle, and has considerable application prospects in the flow field observation and performance improvement of the supersonic separation line nozzle.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A cold flow two-dimensional supersonic separation line nozzle performance and flow schlieren test run platform, comprising: a support structure, a gas supply structure, a servo actuating system, and a supersonic separation line nozzle;

[0007] The support structure includes a base and a thrust frame, and a nozzle support frame and an intake section support frame are installed on the base;

[0008] The gas supply structure includes an intake section, a transition section, and a connection section connected in sequence by flanges. The front end of the intake section is connected to the thrust frame, and the lower part of the intake section is supported by the intake section support frame;

[0009] The servo actuator system includes the servo mechanism, which is respectively connected to the upper servo mechanism support frame and the lower servo mechanism support frame. The servo mechanism is connected to the guiding arm, and the guiding arm is limited by the nozzle side baffle and the nozzle side baffle cover. The nozzle side baffle is connected to the upper side of the nozzle support frame;

[0010] The supersonic separation line nozzle includes a movable part, which is connected to the acrylic plate and the nozzle side baffle. The acrylic plate is sealed with the acrylic baffle by an arc-shaped sealing strip. The acrylic baffle is respectively connected to the nozzle side baffle and the fixed part. The fixed part and the movable part are sealed by a sealing strip. A high-frequency pressure sensor is connected to the wall surface of the movable part to measure the wall pressure. The movable part drives the guiding arm through the servo mechanism to achieve movement.

[0011] Further, the intake section is provided with intake holes, which are connected to the gas supply system through pipelines to input high-pressure and high-flow gas.

[0012] Further, the internal channel of the transition section changes from circular to square to change the cross-sectional shape of the gas flow and transition the circular cross-section to a square cross-section.

[0013] Further, the internal channel of the connection section is square to further rectify the air flow and ensure that the air flow direction and speed entering the supersonic separation line nozzle are consistent.

[0014] Further, the acrylic plate is a high-transparency acrylic plate.

[0015] Further, the fixed part and the movable part are provided with pressure measurement holes for installing the high-frequency pressure sensor (18) to measure the pressures at different positions on the wall surfaces of the fixed part and the movable part.

[0016] Further, the front end of the intake section is connected to a thrust sensor through a thrust frame to record the thrust of the supersonic separation line nozzle.

[0017] Further, the arc-shaped sealing strip is a hard rubber strip.

[0018] The present invention may further include:

[0019] A method for performing cold flow two-dimensional expansion offset nozzle performance and flow schlieren tests using the above test bench, the method including:

[0020] Step 1: Install the test bench and sensors, connect the data acquisition system, and check whether the sensors are connected properly;

[0021] Step 2: Adjust the schlieren system to make the target area clearly and completely imaged in the camera. Turn on the camera to start recording, and at the same time, turn on the data acquisition system and record the test pressure and thrust data;

[0022] Step 3: Start the experiment. Open the pneumatic valve, and the gas supply system inputs high-pressure nitrogen to obtain a stable air flow for a period of time;

[0023] Step 4: Close the pneumatic valve, close the data acquisition system, and stop the camera recording. The experiment ends.

[0024] Furthermore, when starting the experiment, the test stand drives the guide arm to move by controlling the actuation of the servo mechanism, and then the guide arm drives the moving part and the acrylic plate to move; while the servo mechanism is working, high-pressure gas enters the intake section through the intake holes below the intake section, changes the gas cross-sectional shape from circular to square through the transition section, and then flows into the connection section to form a uniform and stable air flow into the supersonic separation line nozzle, and expands in the supersonic separation line nozzle to generate thrust.

[0025] The beneficial effects of the present invention are as follows:

[0026] The present invention can carry out cold flow tests during the swing process of the supersonic separation line nozzle and conduct real-time flow state observation and wall pressure monitoring, obtain the flow evolution and performance change laws during the working process of the supersonic separation line nozzle, and provide technical support for the profile design and performance improvement of the supersonic separation line nozzle.

[0027] The cold flow dual supersonic separation line nozzle performance and flow schlieren test stand proposed by the present invention can reproduce the working state of the dual supersonic separation line nozzle, realize the dynamic swing of the nozzle moving part through the servo mechanism to reproduce the swing process in the actual work of the supersonic separation line nozzle, measure the wall pressure distribution of the nozzle through the pressure sensor to obtain the flow characteristics of the nozzle wall, collect the thrust characteristics of the nozzle through the thrust sensor, and capture the flow field wave system through the schlieren system.

[0028] The cold flow dual supersonic separation line nozzle performance and flow schlieren test stand proposed by the present invention can reproduce the working states at different swing angles through the servo actuation system without replacing components, and measure the influence of the swing angle on the working state of the nozzle to the greatest extent under limited test conditions.

[0029] The cold flow dual supersonic separation line nozzle performance and flow schlieren test stand proposed by the present invention has advantages such as accurate measurement and high observability compared with other test stands. Pressure sensors are installed on the walls of the fixed part and the moving part to achieve real-time pressure monitoring; acrylic plates with high light transmittance are used to obtain flow schlieren images during the working process.

[0030] The cold flow two-dimensional supersonic separated line nozzle performance and flow schlieren test rig proposed by the present invention can conduct nozzle tests with different profiles. On the premise of keeping other components of the test rig unchanged, only the fixing parts, moving parts and acrylic plates need to be replaced to conduct the cold flow test of the working process of the supersonic separated line nozzle with different profiles. The replacement process is simple and efficient, which can significantly improve the test efficiency.

[0031] The present invention can not only realize the swing function of the nozzle, but also realize the visualization observation of the flow field during the swing process to ensure the comprehensiveness and accuracy of the experimental data. The device adopts a modular design, which makes the replacement of the nozzle profile more convenient, greatly improves the flexibility and adaptability of the experiment, provides a more efficient and accurate experimental means for the research of supersonic flow of the nozzle, and helps to promote the in-depth exploration and development of related fields. Brief Description of the Drawings

[0032] Appendix Figure 1 is the structural schematic diagram of the present invention.

[0033] Appendix Figure 2 is the structural schematic diagram of the support structure and air supply structure of the present invention.

[0034] Appendix Figure 3 is the sectional view of the support structure and air supply structure of the present invention.

[0035] Appendix Figure 4 is the assembly drawing of the servo actuator system and the supersonic separated line nozzle of the present invention.

[0036] Appendix Figure 5 is the local structure assembly drawing of the supersonic separated line nozzle of the present invention.

[0037] Appendix Figure 6 is the structural schematic diagram of the acrylic baffle of the present invention.

[0038] In the figure: 1 - base; 2 - nozzle support frame; 3 - connection section; 4 - transition section; 5 - intake section; 6 - thrust frame; 7 - intake section support frame; 8 - intake hole; 9 - upper servo mechanism support frame; 10 - lower servo mechanism support frame; 11 - servo mechanism; 12 - nozzle side baffle; 13 - nozzle side baffle cover; 14 - guide arm; 15 - acrylic plate; 16 - acrylic baffle; 17 - fixing part; 18 - pressure sensor; 19 - moving part; 20 - sealing strip; 21 - arc sealing strip. Detailed Embodiment

[0039] The present invention will be further described below with reference to the accompanying drawings.

[0040] The present invention provides a cold flow two-dimensional expansion and deflection nozzle performance and flow schlieren test rig, as Figures 1-6As shown in the figure, it consists of: a support structure, a gas supply structure, a servo actuator system, and a supersonic separation line nozzle, where:

[0041] As shown in the Figure 2 figure, the support structure includes a base 1, a nozzle support frame 2, a thrust frame 6, and an intake section support frame 7;

[0042] The base 1 is connected to the nozzle support frame 2 and the intake section support frame 7;

[0043] The thrust frame 6 is connected to the intake section 5 through a flange, the intake section 5 is connected to the transition section 4 through a flange, the transition section 4 is connected to the connection section 3 through a flange, and the connection section 3 is connected to the fixing member 17 of the supersonic separation line nozzle through a flange;

[0044] In this embodiment, the base 1 is the main load-bearing structure.

[0045] In this embodiment, the intake section support frame 7 is an important support device for supporting the intake section 5, providing support for the engine, and keeping the engine horizontal.

[0046] More specifically, the nozzle support frame 2 and the intake section support frame 7 are fixedly connected to the base 1 through bolts. The intake section support frame 7 fixedly supports the intake section 5, and the intake section 5 is connected to the thrust frame 6, which can be used for thrust measurement.

[0047] In this embodiment, the transition section 4 is a pipe section whose internal channel changes from circular to square, used to change the cross-sectional shape of the gas flow and transition the circular cross-section to a square cross-section.

[0048] In this embodiment, the connection section 3 is a square pipe, which further rectifies the air flow to ensure that the air flow direction and speed entering the supersonic separation line nozzle are consistent.

[0049] In this embodiment, the pressure hole 8 is connected to the gas supply system through a pipeline to connect the gas supply system with the intake section 5. When the equipment is working, the high-pressure nitrogen provided by the gas supply system flows into the intake section 5 through the pressure hole 8 to provide high-pressure gas for the supersonic separation line nozzle.

[0050] In this embodiment, the front end of the intake section 5 is connected to the thrust sensor through the thrust frame 6, and then the thrust of the supersonic separation line nozzle.

[0051] As shown in the Figure 3 figure, the gas supply structure includes an intake section 5, a transition section 4, a connection section 3, and an intake hole 8; the intake hole 8 is installed on the intake section 5, and the intake hole 8 is connected to the gas supply system through a pipeline to provide high-pressure and high-flow gas; the lower part of the intake section 5 is connected to the intake section support frame 7.

[0052] As shown in the Figure 4As shown in the figure, the servo actuator system includes an upper servo mechanism support frame 9, a lower servo mechanism support frame 10, a servo mechanism 11, a nozzle side baffle 12, a nozzle side baffle cover 13, and a guide arm 14;

[0053] In this embodiment, the servo mechanism 11 is connected to the upper servo mechanism support frame 9 and the lower servo mechanism support frame 10, and the lower servo mechanism support frame 10 is connected to the nozzle support frame 2;

[0054] The guide arm 14 is connected to the servo mechanism 11 and the moving part 19. By driving the guide arm 14 to move through the servo mechanism 11, the movement of the moving part 19 is realized;

[0055] The nozzle side baffle 12 is connected to the nozzle side baffle cover 13 to limit the guide arm 14;

[0056] The supersonic separation line nozzle acrylic plate 15, acrylic baffle 16, fixing part 17, moving part 19, sealing strip 20, pressure sensor 18, and arc-shaped sealing strip 21.

[0057] On the wall surface of the moving part 19 of the supersonic separation line nozzle, a high-frequency pressure sensor 18 is connected to measure the wall surface pressure. On the side surface of the moving part 19, an acrylic baffle 12 is connected. The nozzle side baffle 12 is connected to the upper side of the nozzle support frame 2, and the lower side of the nozzle support frame 2 is connected to the base 1;

[0058] The moving part 19 is connected to an acrylic plate 15, and the acrylic plate 15 and the acrylic baffle 16 are sealed by an arc-shaped sealing strip 21;

[0059] The acrylic baffle 16 is connected to the nozzle side baffle 12 and the fixing part 17, and the fixing part 17 and the moving part 19 are sealed by a sealing strip 20.

[0060] The supersonic separation line nozzle in this embodiment is a two-dimensional planar nozzle, whose profile is composed of a fixing part 17 and a moving part 19, and its inner surface is the experimental section in contact with the airflow. The fixing part 17 is provided with 1 pressure measurement hole, and the moving part 19 is provided with 4 pressure measurement holes for installing the pressure sensor 18, which can measure the pressure distribution at different positions on the wall surface. The fixing part 17 is connected to the connection section 3 through a flange, and the gas enters the supersonic separation line nozzle through the connection section 3 and then expands and flows out. The fixing part 17 and the nozzle side baffle 12 cooperate to press the acrylic baffle 16, and the acrylic baffle 16 presses the acrylic plate 15. A sealing strip 20 is used between the acrylic baffle 16 and the acrylic plate 15 to improve the airtightness. The acrylic plate 15 is provided with threaded holes for connecting with the moving part 19 through bolts to realize the synchronous movement of the acrylic plate 15 and the moving part 19 during the working process. Threaded holes are provided on the wall surface of the moving part 19 for connecting with the guide arm 14, and the guide arm 14 is connected to the servo mechanism 11.

[0061] The guiding arm 14 is an arc-shaped connecting piece.

[0062] In this embodiment, the acrylic baffle 16 is a semi-circular baffle used to press the acrylic plate 15. Its airtightness at the connection is ensured by the sealing strip 20. This connection method provides good airtightness on the premise of realizing the relative movement between the acrylic plate 15 and the fixing member 17.

[0063] Preferably, the acrylic plate 15 has high transparency and good toughness, and can be photographed by a schlieren system to record schlieren images.

[0064] The assembly method of the servo actuator system and the supersonic separation line nozzle in this embodiment: Fix the nozzle fixing member 17 to the connection section 3 through a flange. Connect the lower servo mechanism support member 10 to the nozzle support frame 2 by bolts to fix the lower servo mechanism support member 10. Connect the nozzle side baffle 12 to the lower servo mechanism support member 10 by bolts, and press the acrylic baffle 16 through the nozzle side baffle 12 and the fixing member 17. Press the acrylic plate 15 through the acrylic baffle 16 and the movable member 19, and use bolts to connect between the acrylic plate 15 and the movable member 19. This connection method can realize the common movement between the acrylic plate 15 and the movable member 19 to observe the flow field during the swing of the nozzle.

[0065] During operation, by controlling the actuation of the servo mechanism 11, the guiding arm 14 is driven to move, and then the guiding arm 14 drives the movable member 19 and the acrylic plate 15 to move. While the servo mechanism is working, high-pressure gas enters the intake section 5 through the intake hole 8 below the intake section 5, changes the gas cross-sectional shape from circular to square through the transition section 16, and then flows into the connection section 3 to form a uniform and stable air flow into the supersonic separation line nozzle, where it expands to generate thrust.

[0066] While the servo mechanism is working, high-pressure gas enters the intake section 5 through the intake hole 8 below the intake section 5, changes the gas cross-sectional shape from circular to square through the transition section 16, and then flows into the connection section 3 to form a uniform and stable air flow into the supersonic separation line nozzle, where it expands to generate thrust. Pressure measurement holes are provided on the walls of both the nozzle movable member 19 and the fixing member 17 to measure the wall pressure distribution and the real-time change of pressure during the experiment, and a schlieren system is used to record the schlieren images of the flow field through the acrylic plate 15.

[0067] The stroke of the servo mechanism in this embodiment can be selected as 50 mm.

[0068] As shown in the appendix Figure 5As shown, the gap between the fixed part 17 and the movable part 19 uses a sealing strip 20 to ensure airtightness. There is 1 pressure measurement hole on the inner surface of the fixed part 17, and 4 pressure measurement holes on the inner surface of the movable part 19. Pressure sensors 18 are connected to the outer surfaces.

[0069] As shown in the appendix Figure 6 As shown, the assembly drawing of the acrylic baffle 16 and the arc-shaped sealing strip 21, where the acrylic baffle 16 presses the acrylic plate 15 against the side wall of the nozzle. An arc-shaped groove is provided on the joint surface of the acrylic baffle 16 and the acrylic plate 15 to install the arc-shaped sealing strip 21, further improving the airtightness at the connection between the acrylic baffle 16 and the acrylic plate 15.

[0070] This embodiment also provides a method for testing the performance and flow schlieren of a cold flow two-dimensional expansion and yawed nozzle using the above test bench. The method includes:

[0071] Step 1: Install the test bench and sensors, connect the data acquisition system, and check whether the sensors are connected properly;

[0072] Step 2: Adjust the schlieren system to make the target area clearly and completely imaged in the camera. Turn on the camera to start recording, and at the same time turn on the data acquisition system and record the test pressure and thrust data;

[0073] Step 3: Start the experiment. Open the pneumatic valve, and the gas supply system inputs high-pressure nitrogen to obtain a stable air flow for a period of time;

[0074] Step 4: Close the pneumatic valve, close the data acquisition system, and close the camera recording. The experiment ends.

[0075] Among them, the test process of the supersonic separation line nozzle: Before the start of the test, turn on the equipment for recording test data to start recording, then open the valve of the gas supply system to supply high-pressure nitrogen into the engine. Stop the ventilation after a period of ventilation, save the test data, change the total pressure of the inflowing nitrogen to conduct repeated tests, and analyze and summarize the experimental results.

[0076] Adopting the above technical solution, the test bench of the present invention can reproduce the working process of the supersonic separation line nozzle at different yaw angles and different yaw speeds under ground experimental conditions. The flow state of the two-dimensional nozzle and the wall pressure distribution characteristics are respectively obtained through the schlieren system and the pressure sensor, which are used to test the working state of the supersonic separation line nozzle under the condition of high-pressure cold flow nitrogen input. It has the advantages of simple principle, high adaptability, and accurate measurement of the working state, and has good application prospects for the test of the supersonic separation line nozzle.

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

Claims

1. A cold flow binary supersonic separation line nozzle performance and flow schlieren test bench, characterized in that: include: Support structure, air supply structure, servo-actuation system and supersonic separation line nozzle; The support structure comprises a base (1) and a thrust frame (6), and a nozzle support frame (2) and an air intake section support frame (7) are mounted on the base (1); The air supply structure comprises an air intake section (5), a transition section (4), and a connection section (3) which are connected in sequence through flanges, the front end of the air intake section (5) is connected to the thrust frame (6), and the lower part of the air intake section (5) is supported by the air intake section support frame (7); The servo actuation system comprises a servo mechanism (11), wherein the servo mechanism (11) is respectively connected to an upper servo mechanism support frame (9) and a lower servo mechanism support frame (10), wherein the servo mechanism (11) is connected to a guide arm (14), wherein the guide arm (14) is limited by a nozzle side baffle plate (12) and a nozzle side baffle plate cover (13), and wherein the nozzle side baffle plate (12) is connected to the upper side of the nozzle support frame (2); The supersonic separation line nozzle comprises a movable part (19), the movable part (19) is connected to an acrylic plate (15) and a nozzle side baffle (12), the acrylic plate (15) and the acrylic baffle (16) are sealed by an arc-shaped sealing strip (21), the acrylic baffle (16) is respectively connected to the nozzle side baffle (12) and a fixed part (17), the fixed part (17) and the movable part (19) are sealed by a sealing strip (20), the wall surface of the movable part (19) is connected to a high-frequency pressure sensor (18) to measure the wall surface pressure, and the movable part (19) drives a guide arm (14) to achieve movement through the servo mechanism (11).

2. The cold flow binary supersonic separation line nozzle performance and flow schlieren test bench according to claim 1 is characterized in that: The air intake section (5) is provided with an air intake hole (8), and the air intake hole (8) is connected to the air supply system through a pipeline to input high-pressure and high-flow gas.

3. The cold flow binary supersonic separation line nozzle performance and flow schlieren test bench according to claim 1 or 2, characterized in that: The internal channel of the transition section (4) is transformed from a circle to a square, so as to change the cross-sectional shape of the gas flow and transform the circular cross-section into a square cross-section.

4. The cold flow binary supersonic separation line nozzle performance and flow schlieren test bench according to claim 1 or 2, characterized in that: The internal channel of the connecting section (3) is square, which further rectifies the airflow and ensures that the direction and speed of the airflow entering the supersonic separation line nozzle are consistent.

5. The cold flow two-dimensional supersonic separation line nozzle performance and flow schlieren test bench according to claim 1 is characterized in that: The acrylic plate (15) is a high-transparency acrylic plate.

6. The cold flow binary supersonic separation line nozzle performance and flow schlieren test bench according to claim 1 or 2, characterized in that: The fixed part (17) and the movable part (19) have pressure measuring holes for installing the high-frequency pressure sensor (18) to measure the pressure at different positions on the wall surface of the fixed part (17) and the movable part (19).

7. The cold flow binary supersonic separation line nozzle performance and flow schlieren test bench according to claim 1 or 2, characterized in that: The front end of the air intake section (5) is connected to a thrust sensor via a thrust frame (6) to record the thrust of the supersonic separation line nozzle.

8. The cold flow binary supersonic separation line nozzle performance and flow schlieren test bench according to claim 1 or 2, characterized in that: The arc-shaped sealing strip (21) is a hard rubber strip.

9. A method for testing the performance and flow schlieren of a cold flow binary expansion biased flow nozzle using the test bench according to any one of claims 1 to 8, characterized in that: The method includes: Step 1: Install the test bench and sensors, connect the data acquisition system, and check whether the sensors are connected normally; Step 2: Adjust the Schlieren system so that the target area is clearly and completely imaged in the camera, turn on the camera to start recording, and at the same time turn on the data acquisition system to record the test pressure and thrust data; Step 3: Start the experiment, open the pneumatic valve, input high-pressure nitrogen into the gas supply system, and obtain a stable airflow for a period of time; Step 4: Close the pneumatic valve, turn off the data acquisition system, turn off the camera recording, and the experiment ends.

10. The method for testing the performance and flow schlieren of a cold flow binary expansion biased flow nozzle on a test bench according to claim 9, characterized in that: When the experiment is started, the test bench controls the servo mechanism (11) to move, thereby driving the guide arm (14), and then the guide arm (14) drives the movable part (19) and the acrylic plate (15) to move. While the servo mechanism is working, high-pressure gas enters the air intake section (5) through the air intake hole (8) below the air intake section (5), changes the cross-sectional shape of the gas from circular to square through the transition section (16), and then flows into the connecting section (3) to form a uniform and stable airflow and enter the supersonic separation line nozzle, where it expands and generates thrust.

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