Stress-deformation compression wedge test model for teaching and its test method

Abstract

The present application belongs to the technical field of high-speed wind tunnel test, and discloses a stress deformation compression wedge wind tunnel test model for teaching and a test method thereof. The base of the test model is a stepped base, which is embedded into a high-speed wind tunnel from outside to inside through a stepped matching mode, and the top surface of the base is flush with the wall surface of the test section of the high-speed wind tunnel. An inclined stress deformation panel is fixed on the top surface of the base, and the stress deformation panel faces the high-speed wind tunnel flow. A plurality of pressure measuring holes are formed on the top surface of the base in front of the stress deformation panel to measure the surface pressure distribution of the top surface of the base. The test method comprises determining test related parameters, installing the base, installing pressure sensors, conducting a teaching test, and closing the high-speed wind tunnel. The test model and the test method thereof provide hardware conditions and measurement interfaces for directly displaying flow phenomena caused by shock waves in a high-speed wind tunnel, quickly adjusting shock wave forms, and evaluating boundary layer control strategies, and have engineering practical value.

Description

Technical Field

[0001] This invention belongs to the field of high-speed wind tunnel testing technology, specifically relating to a stress deformation compression slashing wind tunnel test model and its test method for teaching purposes. Background Technology

[0002] When supersonic and hypersonic airflow passes through the external or internal curved surfaces of an aircraft, the aerodynamic loads borne by the aircraft are characterized by unsteadiness, non-uniformity, extreme overload, and force-thermal coupling. In particular, the aerodynamic loads caused by the three-dimensional effect of shock turbulent boundary layer interaction (STBLI) under real conditions account for a significant portion of the loads, especially in the leading edge and transition undulation area of ​​the aircraft fuselage.

[0003] In aerodynamics experimental teaching, experimental methods for studying flow separation criteria, disturbance modes, and similarity laws in three-dimensional conditions remain commonly used techniques. These methods are of great significance for further developing flow control technologies and improving the quality of flow fields around aircraft. High-speed teaching wind tunnels can precisely control and generate supersonic airflow and are frequently used for research on fundamental aerodynamic problems.

[0004] Currently, there is an urgent need to develop a stress deformation compression slashing wind tunnel test model and its test method for teaching purposes. Summary of the Invention

[0005] One technical problem to be solved by the present invention is to provide a stress-deformation compression slashing wind tunnel test model for teaching purposes. Another technical problem to be solved by the present invention is to provide a test method for the stress-deformation compression slashing wind tunnel test model for teaching purposes, so as to carry out supersonic and hypersonic airflow demonstrations and teaching research.

[0006] The stress-deformation compression slashing wind tunnel test model and its test method for teaching use of the present invention generate target oblique shock waves in the high-speed wind tunnel through supersonic and hypersonic airflow. By applying external excitation to change the state of the stress-deformation panel, the flow phenomena caused by the shock wave under three-dimensional effects can be observed, measured and evaluated, boundary layer parameters can be obtained, and boundary layer control technology can be verified.

[0007] like Figure 1 As shown, the stress-deformation compression slashing wind tunnel test model of the present invention for teaching includes a stress-deformation panel, a bracket, and a base; The base is a stepped base, which is embedded into the high-speed wind tunnel from the outside to the inside through a stepped matching method. The top surface of the base is flush with the test section wall of the high-speed wind tunnel. An inclined stress deformation panel is fixed on the top surface of the base, and the stress deformation panel faces the incoming flow of the high-speed wind tunnel. The leading edge of the stress-deformation panel is fixed to the top surface of the base by a hinge mechanism, and the lower surface of the trailing edge of the stress-deformation panel is supported by a bracket; the angle between the stress-deformation panel and the top surface of the base is the angle of attack α of the stress-deformation panel. Several pressure measuring holes are opened in front of the stress deformation panel and on the top surface of the base. Each pressure measuring hole is connected to a pressure sensor through a pressure measuring tube. The pressure sensor measures the surface pressure distribution on the top surface of the base. The spanwise centerline of the stress-deformation panel is drawn on the upper surface of the stress-deformation panel. The spanwise centerline of the stress-deformation panel is the line where the stress-deformation panel undergoes the greatest deformation.

[0008] Furthermore, the stress-deformation panel is made of shape memory alloy; a reinforcing frame is provided on the lower surface of the stress-deformation panel along its edge.

[0009] Furthermore, the bracket is made of alloy steel; the bracket is a vertical support plate, the lower end of which is fixed to the top surface of the base, and the top end of which is supported on the lower surface of the rear edge of the stress-deformation panel; the height of the bracket is adjustable, and the angle of attack α of the stress-deformation panel can be adjusted by adjusting the height of the bracket.

[0010] Furthermore, the base is made of plexiglass or a metal alloy.

[0011] The experimental method of the stress-deformation compression wedge wind tunnel test model for teaching purposes according to the present invention includes the following steps: S10. Determine the relevant parameters for the experiment; specifically, this includes the following steps: S11. Determine the angle of attack α1 of the target oblique shock wave based on the external curved surface chamfer of the aircraft; S12. Determine the angle of attack α of the stress-deformed panel based on the requirement that the angle of attack α1 of the target oblique shock wave is the same as the angle of attack α of the stress-deformed panel; S13. Determine the height of the bracket based on the angle of attack α of the stress deformation panel; S14. Determine the distribution and location of each pressure measuring hole; S20. Install the base; specifically including the following steps: S21. Determine the dimensions of the base based on the pre-reserved interfaces on the test section wall of the high-speed wind tunnel; S22. According to the relevant test parameters, fix the stress deformation panel and bracket on the base, and adjust the height of the bracket to the correct position. S23. Several pressure testing holes are provided on the top surface of the base, and a pressure testing tube is connected to each pressure testing hole; S24. Install the base on the pre-reserved interface on the test section wall of the high-speed wind tunnel using a step matching method, ensuring that the top surface of the base is flush with the test section wall of the high-speed wind tunnel; S30. Install the pressure sensor; Install and test pressure sensors on each pressure measuring tube to ensure that the pressure sensors are working properly; S40. Conduct teaching experiments; specifically including the following steps: S41. Start the high-speed wind tunnel; In the test section of the high-speed wind tunnel, airflow with the target Mach number is generated. The airflow generates oblique shock waves through the stress-deformed panel, and at the same time, shock wave boundary layer interference phenomenon is generated. S42. Apply external stimulus; Based on the requirement that the spanwise centerline of the stress-deformed panel is the line where the stress-deformed panel undergoes the greatest deformation, external stimuli, including temperature, pressure, or magnetic force, are applied near the spanwise centerline of the stress-deformed panel. S43. Measure the pressure distribution on the top surface of the base; The stress-deformation panel deforms accordingly based on the external excitation and the intensity of the external excitation. The stress-deformation panel convexes or concaves along the spanwise centerline, causing changes in the structure and flow field parameters of the oblique shock wave. Each pressure sensor measures the pressure change on the top surface of the base in real time, providing online assessment data for studying the flow phenomena caused by the shock wave, quickly adjusting the shock wave morphology, and evaluating boundary layer control strategies. S50. Close the high-speed wind tunnel; When the high-speed wind tunnel is shut down and external excitation is removed, the stress-deformed panel returns to its initial flat plate shape.

[0012] The stress-induced deformation compression slashing wind tunnel test model and its test method for teaching purposes provide hardware conditions and measurement interfaces for visually displaying the flow phenomena caused by shock waves in high-speed wind tunnels, quickly adjusting the shock wave morphology, and evaluating boundary layer control strategies, and have practical engineering value. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the stress deformation compression slashing wind tunnel test model for teaching purposes according to the present invention.

[0014] In the figure, 1. Stress-deformed panel; 2. Bracket; 3. Base; 4. Pressure measuring hole; 5. Pressure sensor; 6. Centerline of stress-deformed panel. Detailed Implementation

[0015] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0016] Example: Figure 1 As shown, the stress deformation compression slashing wind tunnel test model for teaching in this embodiment includes a stress deformation panel 1, a bracket 2, and a base 3; The base 3 is a stepped base, which is embedded into the high-speed wind tunnel from the outside to the inside through a stepped matching method. The top surface of the base 3 is flush with the test section wall of the high-speed wind tunnel. An inclined stress deformation panel 1 is fixed on the top surface of the base 3, and the stress deformation panel 1 faces the incoming flow of the high-speed wind tunnel. The front edge of the stress-deformation panel 1 is fixed to the top surface of the base 3 by a hinge mechanism, and the lower surface of the rear edge of the stress-deformation panel 1 is supported by a bracket 2; the included angle between the stress-deformation panel 1 and the top surface of the base 3 is the angle of attack α of the stress-deformation panel. Several pressure measuring holes 4 are opened in front of the stress deformation panel 1 and on the top surface of the base 3. Each pressure measuring hole 4 is connected to a pressure sensor 5 through a pressure measuring tube. The pressure sensor 5 measures the surface pressure distribution on the top surface of the base 3. The stress deformation panel 1 has a spanwise centerline 6 drawn on its upper surface. The stress deformation panel 1 has the largest deformation line 6.

[0017] Furthermore, the stress-deformation panel 1 is made of shape memory alloy; a reinforcing frame is provided on the lower surface of the stress-deformation panel 1 along its edge.

[0018] Furthermore, the bracket 2 is made of alloy steel; the bracket 2 is a vertical support plate, the lower end of which is fixed to the top surface of the base 3, and the top end of which is supported on the lower surface of the rear edge of the stress-deformation panel 1; the height of the bracket 2 is adjustable, and the angle of attack α of the stress-deformation panel can be adjusted by adjusting the height of the bracket 2.

[0019] Furthermore, the base 3 is made of plexiglass or metal alloy.

[0020] The experimental method for the stress-induced deformation compression slashing wind tunnel test model used for teaching in this embodiment includes the following steps: S10. Determine the relevant parameters for the experiment; specifically, this includes the following steps: S11. Determine the angle of attack α1 of the target oblique shock wave based on the external curved surface chamfer of the aircraft; S12. Determine the angle of attack α of the stress-deformed panel based on the requirement that the angle of attack α1 of the target oblique shock wave is the same as the angle of attack α of the stress-deformed panel; S13. Determine the height of bracket 2 based on the angle of attack α of the stress deformation panel; S14. Determine the distribution and location of each pressure measuring hole 4; S20. Install base 3; specifically including the following steps: S21. Determine the dimensions of base 3 based on the pre-reserved interfaces on the test section wall of the high-speed wind tunnel; S22. According to the relevant test parameters, fix the stress deformation panel 1 and bracket 2 on the base 3, and adjust the height of bracket 2 into place. S23. Several pressure measuring holes 4 are provided on the top surface of the base 3, and a pressure measuring tube is connected to each pressure measuring hole 4; S24. Install the base 3 on the pre-reserved interface on the test section wall of the high-speed wind tunnel using a step matching method, ensuring that the top surface of the base 3 is flush with the test section wall of the high-speed wind tunnel; S30. Install pressure sensor 5; Install and test pressure sensor 5 on each pressure measuring tube to ensure that pressure sensor 5 is working properly; S40. Conduct teaching experiments; specifically including the following steps: S41. Start the high-speed wind tunnel; In the test section of the high-speed wind tunnel, an airflow with the target Mach number is generated. The airflow passes through the stress-deformed panel 1 to generate an oblique shock wave, and at the same time, a shock wave boundary layer interference phenomenon is generated. S42. Apply external stimulus; Based on the requirement that the spanwise centerline 6 of the stress-deformation panel is the line where the stress-deformation panel 1 undergoes the greatest deformation, external stimuli, including temperature, pressure or magnetic force, are applied near the spanwise centerline 6 of the stress-deformation panel. S43. Measure the pressure distribution on the top surface of base 3; The stress-deformation panel 1 deforms accordingly based on the external excitation and the intensity of the external excitation. The stress-deformation panel convexes or concaves along the spanwise centerline 6, causing changes in the structure and flow field parameters of the oblique shock wave. Each pressure sensor 5 measures the pressure change on the top surface of the base 3 in real time, providing online assessment data for studying the flow phenomena caused by the shock wave, quickly adjusting the shock wave morphology, and evaluating boundary layer control strategies. S50. Close the high-speed wind tunnel; When the high-speed wind tunnel is shut down and external excitation is removed, the stress-deformed panel 1 returns to its initial flat plate shape.

[0021] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. For those skilled in the art, all features disclosed in the present invention, or all steps in all methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any way without departing from the principles of the present invention. The present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A stress-ductility compression wedge test model for teaching, characterized in that, The stress deformation compression slashing wind tunnel test model includes a stress deformation panel (1), a bracket (2), and a base (3). The base (3) is a stepped base, which is embedded into the high-speed wind tunnel from the outside to the inside through a step matching method. The top surface of the base (3) is flush with the test section wall of the high-speed wind tunnel. An inclined stress deformation panel (1) is fixed on the top surface of the base (3), and the stress deformation panel (1) faces the incoming flow of the high-speed wind tunnel. The front edge of the stress-deformation panel (1) is fixed to the top surface of the base (3) by a hinge mechanism, and the lower surface of the rear edge of the stress-deformation panel (1) is supported by a bracket (2). The angle between the top surface of the stress-deformation panel (1) and the base (3) is the angle of attack α of the stress-deformation panel; Several pressure measuring holes (4) are opened in front of the stress deformation panel (1) and on the top surface of the base (3). Each pressure measuring hole (4) is connected to a pressure sensor (5) through a pressure measuring tube. The pressure sensor (5) measures the surface pressure distribution on the top surface of the base (3). The stress deformation panel (1) has a spanwise centerline (6) drawn on its upper surface. The spanwise centerline (6) is the line where the stress deformation panel (1) undergoes the greatest deformation.

2. The stress-induced compression wedge wind tunnel test model for teaching of claim 1, wherein, The stress deformation panel (1) is made of shape memory alloy; a reinforcing frame is provided on the lower surface of the stress deformation panel (1) along the edge of the stress deformation panel (1).

3. The stress-induced compression wedge wind tunnel test model for teaching of claim 1, wherein, The bracket (2) is made of alloy steel; the bracket (2) is a vertical support plate, the lower end of the support plate is fixed on the top surface of the base (3), and the top end of the support plate is supported on the lower surface of the rear edge of the stress deformation panel (1); the height of the bracket (2) is adjustable, and the angle of attack α of the stress deformation panel is adjusted by adjusting the height of the bracket (2).

4. The stress-induced compression wedge wind tunnel test model for teaching of claim 1, wherein, The base (3) is made of plexiglass or metal alloy.

5. A test method for a stress-induced deformation compression-wedge wind tunnel test model used for teaching, wherein the model is used for any one of claims 1 to 4, characterized in that, Includes the following steps: S10. Determine the relevant parameters for the experiment; Specifically, the following steps are included: S11. Determine the angle of attack α1 of the target oblique shock wave based on the external curved surface chamfer of the aircraft; S12. Determine the angle of attack α of the stress-deformed panel based on the requirement that the angle of attack α1 of the target oblique shock wave is the same as the angle of attack α of the stress-deformed panel; S13. Determine the height of bracket (2) based on the angle of attack α of the stress deformation panel; S14. Determine the distribution and location of each pressure measuring hole (4); S20. Install the base (3); specifically including the following steps: S21. Determine the dimensions of the base (3) based on the pre-reserved interface on the test section wall of the high-speed wind tunnel; S22. According to the relevant test parameters, fix the stress deformation panel (1) and bracket (2) on the base (3), and adjust the height of the bracket (2) to the correct position. S23. Several pressure measuring holes (4) are provided on the top surface of the base (3), and a pressure measuring tube is connected to each pressure measuring hole (4); S24. Install the base (3) on the reserved interface on the test section wall of the high-speed wind tunnel by means of step matching, and ensure that the top surface of the base (3) is flush with the test section wall of the high-speed wind tunnel; S30. Install pressure sensor (5); Install and test pressure sensors (5) on each pressure measuring tube to ensure that the pressure sensors (5) are working properly; S40. Conduct teaching experiments; specifically including the following steps: S41. Start the high-speed wind tunnel; In the test section of the high-speed wind tunnel, the airflow with the target Mach number is generated. The airflow generates oblique shock waves through the stress deformation panel (1), and at the same time, shock wave boundary layer interference phenomenon is generated. S42. Apply external stimulus; According to the requirement that the spanwise centerline (6) of the stress-deformation panel is the line where the stress-deformation panel (1) undergoes the greatest deformation, external stimuli, including temperature, pressure or magnetic force, are applied near the spanwise centerline (6) of the stress-deformation panel. S43. Measure the pressure distribution on the top surface of the base (3); The stress-deformation panel (1) deforms according to the external excitation and the intensity change of the external excitation. The stress-deformation panel convexes or concaves along the center line (6) of the spanwise direction, causing changes in the structure and flow field parameters of the oblique shock wave. Each pressure sensor (5) measures the pressure change on the top surface of the base (3) in real time, providing online assessment data for studying the flow phenomena caused by the shock wave, quickly adjusting the shock wave morphology, and evaluating the boundary layer control strategy. S50. Close the high-speed wind tunnel; When the high-speed wind tunnel is shut down and external excitation is removed, the stress-deformed panel (1) returns to its initial flat plate shape.

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