Method for regulating and controlling interference of shock wave boundary layer through multi-path plasmas

Abstract

Providing a compression corner shock wave / boundary layer interference model, and designing a state Mach number between Mach 1 and Mach 5; installing a manual transition tape at the upstream of the separation area; a U-shaped electrode cover plate is inserted into the insulating material; a groove array with the same size is formed in the upper surface of the insulating material so as to install a U-shaped electrode cover plate; two rows of grooves are formed in the surface of the insulating material in the flow direction; each row of grooves comprises a plurality of grooves which are uniformly distributed along the flow direction, and the adjacent grooves are kept at the same distance; cylindrical stepped holes are formed in the outward extending positions of the two ends of each row of grooves. The invention also provides a method for regulating and controlling the interference of the shock wave boundary layer by the multi-path plasmas. A plurality of plasma arrays are arranged in front of a separation area, a continuous impact disturbance effect is generated on a wave system structure by utilizing a strong impact effect and a heat effect of high-energy plasmas, and a hot gas mass is formed to regulate and control near-wall shock waves, so that the influence of a reverse pressure gradient on a boundary layer is reduced, and the low-frequency instability of the shock waves is improved; and flow separation induced by shock wave / boundary layer interference is slowed down.

Description

Technical Field

[0001] The invention relates to the technical field of flow control, and in particular to a method for multi-path plasma regulation of shock wave / boundary layer interference. Background Art

[0002] Shock waves are a common flow phenomenon in the field of supersonic navigation. When the flight speed exceeds Mach 1, the incoming flow will inevitably encounter irregular objects such as corners and wedges on the aircraft body. The incoming flow cannot pass through these areas smoothly, so the airflow in front is hindered, and the speed of the airflow behind remains unchanged, causing the gas in this area to be compressed, thus forming multiple compression waves. Due to the induction of the pressure gradient, the multiple compression waves are combined into one, which is called a shock wave. The shock wave causes a huge change in air pressure, which often interferes strongly with other flow field structures and has a profound impact on the supersonic flow field.

[0003] The incoming flow and the body wall interact with each other to form a boundary layer, and the mutual disturbance between the shock wave and the boundary layer is called shock wave / boundary layer interaction. Figure 1 As shown in the figure, the high-energy shock wave causes a strong adverse pressure gradient, and the flow direction of the inner layer of the boundary layer is reversed, forcing the incoming flow to be lifted up and away from the near wall to form a shear layer. The resulting series of compression waves converge into a separation shock wave. The separation area is full of low-energy airflow, and the boundary layer can only bypass this area, forming a separation bubble locally. The shear layer returns to the wall area again and decelerates, thereby inducing a reattachment shock wave. The shock wave forms a strong wall normal pressure gradient, which causes a huge pressure jump and compression phenomenon in the boundary layer during the separation and reattachment processes, causing a sharp increase in heat flow locally, which is very easy to damage the surface material of the aircraft. In addition, the shock wave reciprocates back and forth with the expansion and contraction of the separation zone. This movement is often low-frequency, so it may resonate with important components such as wings and air inlets, which will have a fatal effect on the aircraft in severe cases.

[0004] Plasma flow control has natural advantages in flow control of shock wave / boundary layer interference due to its simple structure, wide bandwidth, fast response, and no moving parts. At present, most experimental studies on plasma flow control at home and abroad are limited to the layout of a single group of exciters. When a group of exciters releases plasma, the shock wave instability is weakened, but the unstable frequency does not change, and the separation is not suppressed. The main reasons include: first, the control time is too short. Since the shock wave generated by the excitation flows very fast, the effective time scale is only about 200μs; second, the excitation scale is too small, and the control effect of a single shock wave is often not obvious enough. Therefore, it is feasible to innovatively expand plasma excitation to multi-channel array excitation to form a continuous excitation effect and extend the control time, which is feasible for improving shock wave / boundary layer interference. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a compression corner shock wave / boundary layer interference model, hereinafter referred to as "model", wherein the design state Mach number is between Mach 1 and 5; the model surface is smooth and the flow direction is long; an artificial transition zone is installed upstream of the separation zone;

[0006] The plasma actuator is processed by using insulating materials, and a U-shaped electrode cover is inserted into the insulating material; the U-shaped electrode cover is composed of a U-shaped conductive metal and an insulating sleeve just embedded therein, and the overall shape is a rectangular parallelepiped, and the upper surfaces of the U-shaped conductive metal and the insulating sleeve are flush;

[0007] An array of grooves of the same size is opened on the upper surface of the insulating material to install a U-shaped electrode cover plate; the groove array is installed at the upstream position of the separation zone at the corner; two rows of grooves are arranged on the surface of the insulating material along the flow direction, and the two rows of grooves are symmetrical about the symmetry axis of the insulating material in the direction of expansion; each row of grooves includes a plurality of grooves evenly distributed along the flow direction, and the same spacing is maintained between adjacent grooves; each groove is arranged along the flow direction, so the line connecting the centers of the two ends of the U-shaped conductive metal is also along the flow direction; the two ends of the U-shaped conductive metal are exposed to the air; the upper surface of the U-shaped electrode cover plate is flush with the upper surface of the insulating material, and the upper surface of the insulating material is flush with the upper surface of the model;

[0008] Holes are punched vertically downward on the surface of the insulating material extending outward from both ends of each row of grooves to set cylindrical stepped holes. There are four cylindrical stepped holes in total in two rows of grooves. The cylindrical stepped holes consist of two large and small cylindrical holes. The small cylindrical hole is close to the upper surface of the exciter and is used to install the cylindrical electrode. The large cylindrical hole is close to the lower surface of the exciter and needs to be completely opened so that the high-voltage wires connected to the cylindrical electrode can be placed from bottom to top.

[0009] In one embodiment of the present invention,

[0010] The model length is between 350mm-420mm and the width does not exceed 80mm;

[0011] The slope deflection angle is between 20°-32°;

[0012] The width of the artificial transition zone is between 6-12mm;

[0013] The model making material has the characteristics of high strength, deformation resistance and wear resistance, and has no obvious protrusions and recesses;

[0014] The plasma actuator is made of acrylic plastic material.

[0015] In a specific embodiment of the present invention,

[0016] The frontmost electrode of the groove array shall not exceed 180mm in front of the boundary layer separation zone at the corner.

[0017] In another embodiment of the present invention,

[0018] The length of a single U-shaped electrode cover is between 8-10mm, the width is between 1.5-2.5mm, and the depth is between 5-7mm, ensuring that the distance between adjacent electrodes is within the range of 0.3-0.8mm;

[0019] A single U-shaped electrode cover is one line, and the total number of U-shaped electrode covers installed is more than 20 lines.

[0020] In yet another embodiment of the present invention,

[0021] Drill holes vertically downward on the surface of the insulating material extending 1-2 mm outward from both ends of each row of grooves;

[0022] The diameter of the small cylindrical hole is about 1mm and the length is 4-6mm; the diameter of the large cylindrical hole is about 4mm;

[0023] The high-voltage wires are sealed with high-temperature resistant insulating sealant and are externally connected to other circuit components.

[0024] The electrical connections for the compression corner shock wave / boundary layer interference model above are as follows:

[0025] A high-voltage pulse voltage source is used to apply positive and negative voltages to the U-shaped electrode cover plate respectively; the working voltage of the high-voltage pulse voltage source is 0 to 20 kV and the frequency is 0 to 5 kHz;

[0026] Select any cylindrical electrode at both ends of each row of grooves as the positive end of the exciter, and the cylindrical electrode at the other end as the negative end of the exciter; the positive end of the high-voltage pulse voltage source is directly connected to the positive end of the exciter through the first diode, and the negative end of the high-voltage pulse voltage source is grounded; the DC voltage source, the current limiting resistor, and the capacitor are connected in sequence to form a loop, and the DC voltage source is connected to both ends of the capacitor; the positive end of the second diode is connected to the connection point of the current limiting resistor and the capacitor, the negative end of the second diode is connected to the positive end of the exciter, and the negative end of the exciter is grounded; when measuring, the oscilloscope test end is connected to the positive end of the exciter, and the negative end of the oscilloscope is grounded.

[0027] In another specific embodiment of the present invention,

[0028] The plasma discharge voltage is set to 20 kV, the discharge frequency is set to 500 Hz, the rising edge is 100 ns, the falling edge is 100 ns, and the pulse width is 100 ns; the current limiting resistor is 500 ohms.

[0029] In another specific embodiment of the present invention,

[0030] The model is made of insulating PEEK material, with a design state of Mach number 2, a length of 378mm, a width of 80mm, a height of 52mm, a leading edge wedge angle of 10°, and a rear end compression corner angle of 24°. A boundary layer transition zone is arranged on the upper surface of the model along the span direction at a distance of 15mm from the leading edge of the model. The transition zone is 80mm long and runs through the span direction. The transition zone width is 10mm.

[0031] The total length of the exciter is 146 mm, the width is 40 mm, and the height is 12 mm. 30 plasma discharge arrays are arranged on the short side symmetry axis, that is, 15 plasma discharge arrays are symmetrically arranged on the left and right sides of the short side symmetry axis, each plasma discharge array is a U-shaped electrode cover plate, the two ends of the 15 U-shaped electrode covers are in a straight line, and the straight line is parallel to the long side of the model, and the 15 U-shaped electrode covers are kept at the same distance; the electrode surface is flush with the exciter surface; the front end U-shaped electrode cover plate is 160 mm away from the compression corner, the spacing between adjacent U-shaped electrode covers along the flow direction is 0.5 mm, and the spacing between opposite U-shaped electrode covers along the span direction is 30 mm.

[0032] The working principle of the above compression corner shock wave / boundary layer interference model is as follows:

[0033] When the circuit is working, the exciter receives an instantaneous high-energy pulse from a high-voltage pulse voltage source, and the polarity of the cylindrical electrode changes drastically in an instant, resulting in the polarization of adjacent U-shaped conductive metals; since the U-shaped conductive metals are very close to each other, the metal polarities attract each other, so the polarization of one U-shaped conductive metal will cause the polarization of all U-shaped conductive metals in turn, thus forming a plasma excitation array; the electrodes at both ends of a single U-shaped conductive metal are blocked by an insulating sleeve, and a high-voltage potential difference is formed between the two metal ends of adjacent U-shaped conductive metals that are close to each other, and the distance scale is very small, which can easily break through the air medium to form a plasma path; since the plasma discharge channel is difficult to maintain for a long time in the air, a capacitor is required to release a large current to supplement the loss of the plasma discharge channel and enhance the energy release of the plasma in the air; the two diodes in the circuit are used to maintain the positive direction of the current to prevent the reverse direction from causing uncontrollable effects such as burning the circuit.

[0034] A method for multi-path plasma regulation of shock wave boundary layer interference is also provided, which is based on the above compression corner shock wave / boundary layer interference model, specifically:

[0035] Before excitation: Under the design state of Mach 2, the compression corner shock wave / boundary layer interference model, the incoming flow is compressed to form a shock wave, that is, the model is in the rated working state; the forebody boundary layer develops into a turbulent boundary after passing through the transition zone. Due to the induction of the strong adverse pressure gradient of the shock wave, the incoming flow boundary layer no longer adheres to the wall, and flow separation occurs to form a separation shock wave and a reattachment shock wave; the shock wave foot moves back and forth in the intermittent zone; the intensity of the reattachment shock wave is significantly smaller than that of the separation shock wave, which further strengthens the shock wave / boundary layer interference, causing more serious flow separation and having a serious impact on the supersonic flow field structure;

[0036] After excitation: high-energy plasma excitation is applied to 30 discharge areas at the same time, and the discharge excitation generates 15 high-energy shock waves; after the separation shock wave is regulated, the angle with the wall is reduced, and the movement frequency is reduced; the plasma thermal effect produces a large-scale, slowly moving controlled hot air mass, with a flow length of about ten times the length of the separation zone, and the effective regulation time is twice the regulation time of a single set of exciters; the excitation also has a significant regulation effect on the reattachment shock wave, and the morphology shows obvious bifurcation, thereby changing the original morphology of the spatial interference zone; at this time, the low-frequency instability of the separation shock wave is improved to a certain extent, and the influence on the adverse pressure gradient of the boundary layer has been greatly weakened, thereby improving the boundary layer flow separation phenomenon.

[0037] Aiming at the demand for shock wave / boundary layer interference control in a supersonic environment and the characteristics of a high-altitude, high-speed flight environment, the present invention arranges a multi-channel plasma array in front of the separation zone and utilizes the strong impact effect and thermal effect of high-energy plasma to, on the one hand, produce a continuous impact disturbance on the wave system structure, and on the other hand, form a hot air mass to control the near-wall shock wave, thereby reducing the influence of the adverse pressure gradient on the boundary layer, improving the low-frequency instability of the shock wave, and mitigating the flow separation induced by the shock wave / boundary layer interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A diagram showing the shock wave / boundary layer interference effect;

[0039] Figure 2 Schematic diagram of U-shaped electrode cover

[0040] Figure 3 Showing the high energy discharge circuit diagram of the present invention;

[0041] Figure 4 A specific design diagram of a compression corner shock wave / boundary layer interference model showing a specific example;

[0042] Figure 5 The diagram shows the effect of shock wave on shock wave / boundary layer interference regulation;

[0043] Figure 6 A diagram showing the effect of controlling hot air masses on shock wave / boundary layer interference. DETAILED DESCRIPTION

[0044] The present invention is applicable to flow control tests for shock wave / boundary layer interference. Taking the compression corner shock wave / boundary layer interference model (this model is well known to those skilled in the art, hereinafter referred to as "model") as an example, the design state Mach number should be between Mach 1 and 5 to meet the supersonic condition. The model length should be between 350mm-420mm, the width should not exceed 80mm, and it should have the characteristics of smooth surface and long flow direction, so as to ensure that the incoming flow can form a boundary layer before the slope, and provide an installation platform for a large-area plasma array. In order to make the shock wave / boundary layer interference and flow separation phenomenon more obvious, the slope deflection angle is preferably between 20°-32°, so that the induced separation shock wave is more obvious, and at the same time, it is ensured that the oblique shock wave will not be converted into a normal shock wave. The incoming flow is 1-3 Mach laminar flow, and an artificial transition zone is installed upstream of the separation zone, with a width between 6-12mm, to ensure that the laminar flow is transformed into boundary turbulence before the separation line. The material used to make the model should have the characteristics of high strength, deformation resistance and wear resistance, without obvious protrusions and recessed gaps, to ensure working safety under supersonic conditions.

[0045] The plasma actuator is made of insulating acrylic plastic material, and a U-shaped electrode cover is inserted inside the insulating material. Figure 2 As shown, the U-shaped electrode cover plate is composed of a U-shaped conductive metal and an insulating sleeve plate just embedded therein, and the overall shape is a rectangular parallelepiped, and the upper surfaces of the U-shaped conductive metal and the insulating sleeve plate are flush.

[0046] An array of grooves of the same size is opened on the upper surface of the insulating material to install the U-shaped electrode cover. The groove array needs to be installed upstream of the separation zone at the corner, and the front-end electrode must not exceed 180mm in front of the boundary layer separation zone at the corner, otherwise the shock wave and hot air mass will be greatly weakened before reaching the separation zone. Figure 4 As shown, two rows of grooves are arranged along the flow direction on the surface of the insulating material, and the two rows of grooves are symmetrical about the symmetry axis of the insulating material in the extension direction; each row of grooves includes a plurality of grooves evenly distributed along the flow direction, and the same spacing is maintained between adjacent grooves; each groove is arranged along the flow direction, so the line connecting the centers of the two ends of the U-shaped conductive metal also follows the flow direction. The two ends of the U-shaped conductive metal are exposed to the air. The upper surface of the U-shaped electrode cover is flush with the upper surface of the insulating material, and the upper surface of the insulating material is flush with the upper surface of the model. Positive and negative voltages are applied to the U-shaped electrode cover respectively, and the electrode breaks through the air to form a plasma discharge circuit, thereby applying excitation to the flow field.

[0047] A single U-shaped electrode cover is one path, and the total number of U-shaped electrode covers installed is at least 20 to ensure that a large number of shock waves form a continuous impact on the shock wave system. The length of a single U-shaped electrode cover is between 8-10mm, the width is within the range of 1.5-2.5mm, and the depth is between 5-7mm. At the same time, the distance between adjacent electrodes is ensured to be within the range of 0.3-0.8mm, and the time interval between adjacent shock waves reaching the separation zone is ensured to be within 30μs to prevent the shock wave from returning to its original form.

[0048] Holes are punched vertically downward on the surface of the insulating material extending 1-2mm outward from both ends of each row of grooves to set cylindrical stepped holes. There are four cylindrical stepped holes in total in two rows of grooves. The cylindrical stepped holes consist of two large and small cylindrical holes. The small cylindrical hole is close to the upper surface of the exciter, with a diameter of about 1mm and a length of 4-6mm, and is used to install cylindrical electrodes; the large cylindrical hole is close to the lower surface of the exciter, with a diameter of about 4mm, and needs to be completely opened to place the high-voltage wire connected to the cylindrical electrode from bottom to top. The high-voltage wire is sealed with high-temperature resistant insulating sealant and connected to other circuit components externally.

[0049] In terms of circuit connection, such as Figure 3 As shown. Select any cylindrical electrode at both ends of each row of grooves as the positive end of the exciter, and the cylindrical electrode at the other end as the negative end of the exciter. Since each row of grooves is designed symmetrically about the symmetry axis of the long side of the exciter, the polarity of the two cylindrical electrodes on the same side can be different. The positive end of the high-voltage pulse voltage source is directly connected to the positive end of the exciter through the first diode, and the negative end of the high-voltage pulse voltage source is grounded. The working voltage of the high-voltage pulse voltage source is 0~20kV, and the frequency is 0~5kHz. The DC voltage source, the current limiting resistor, and the capacitor are connected in sequence to form a loop. The DC voltage source is connected to both ends of the capacitor to play a charging and discharging role, and the current limiting resistor is used to protect the circuit. The positive end of the second diode is connected to the connection point of the current limiting resistor and the capacitor, the negative end of the second diode is connected to the positive end of the exciter, and the negative end of the exciter is grounded. During measurement, the oscilloscope test terminal is connected to the positive end of the exciter, and the negative end of the oscilloscope is grounded.

[0050] When the circuit is working, the exciter receives an instantaneous high-energy pulse from the high-voltage pulse voltage source, and the polarity of the cylindrical electrode changes drastically in an instant, resulting in the polarization of adjacent U-shaped conductive metals. Since the U-shaped conductive metals are very close to each other, the metal polarities attract each other, so the polarization of one U-shaped conductive metal will cause the polarization of all U-shaped conductive metals in turn, thus forming a plasma excitation array. The electrodes at both ends of a single U-shaped conductive metal are blocked by an insulating sleeve, and a high-voltage potential difference is formed between the two metal ends of adjacent U-shaped conductive metals, and the distance scale is very small, which can easily break through the air medium to form a plasma path. Since the plasma discharge channel is difficult to maintain for a long time in the air, a capacitor is required to release a large current to supplement the loss of the plasma discharge channel and enhance the energy release of the plasma in the air. The two diodes in the circuit are used to maintain the positive direction of the current to prevent the reverse direction from causing uncontrollable effects such as burning the circuit.

[0051] In a specific embodiment of the present invention, Figure 4 shown. Figure 4 This is a specific design drawing of the compression corner shock wave / boundary layer interference model. The model uses insulating PEEK material, the design state is Mach number 2, length 378mm, width 80mm, height 52mm, model leading edge wedge angle is 10°, and the rear end compression corner angle is 24°. The boundary layer transition zone is arranged along the span direction on the upper surface of the model 15mm away from the leading edge of the model. The transition zone is 80mm long, runs through the span direction, and the transition zone width is 10mm. It has been verified experimentally that the laminar boundary layer is transformed into turbulent flow after passing through the transition zone, thereby generating a natural resistance to flow separation.

[0052] A groove is opened along the flow direction on the upper surface of the model. The groove is kept at a certain distance from the front boundary layer transition zone and the rear slope, and the groove is symmetrical about the flow axis of the upper surface of the model. The size of the groove can just accommodate the exciter. The exciter is installed in the groove by screws, and is in close contact with the installation edge of the groove to prevent gaps. The exciter is flush with the upper surface of the model. The total length of the exciter is 146mm, the width is 40mm, and the height is 12mm. 30 plasma discharge arrays are arranged on the short side symmetry axis, that is, 15 plasma discharge arrays are symmetrically arranged on the left and right sides of the short side symmetry axis. Each plasma discharge array is a U-shaped electrode cover plate. The two ends of the 15 U-shaped electrode covers are on a straight line, and the straight line is parallel to the long side of the model. The 15 U-shaped electrode covers are kept at the same distance. The electrode surface is flush with the exciter surface to prevent the introduction of additional disturbances. The front end U-shaped electrode cover is 160 mm away from the compression corner, the spacing between adjacent U-shaped electrode covers along the flow direction is 0.5 mm, and the spacing between opposite U-shaped electrode covers along the span direction is 30 mm.

[0053] The plasma discharge voltage is set to 20kv, the discharge frequency is set to 500Hz, the rising edge is 100ns, the falling edge is 100ns, and the pulse width is 100ns. After the capacitor is fully charged, it continues to provide discharge energy to the exciter. To prevent the charging circuit from being burned out, a 500 ohm current limiting resistor is set in the loop. The diode provides unidirectional current, providing good working conditions for the stable operation of the plasma discharge exciter.

[0054] During the implementation of the present invention, a plasma actuator is used to arrange a multi-channel high-energy plasma array in front of the interference zone, and the strong impact effect and thermal effect of the high-energy plasma are used to produce a continuous impact disturbance on the wave system structure and to form a hot air mass to regulate the near-wall shock wave, thereby reducing the influence of the adverse pressure gradient on the boundary layer, improving the low-frequency instability of the shock wave, and slowing down the flow separation induced by the shock wave / boundary layer interference.

[0055] Before excitation: Compression corner shock wave / boundary layer interference model Under the design state of Mach 2, the incoming flow is compressed to form a shock wave, that is, the model is in the rated working state. After the forebody boundary layer passes through the transition zone, it develops into a turbulent boundary. Due to the induction of the strong adverse pressure gradient of the shock wave, the incoming flow boundary layer no longer adheres to the wall, and flow separation occurs to form a separation shock wave and a reattachment shock wave. The angle of the separation shock wave is 41.585°, the shock wave foot moves back and forth in the intermittent zone, and the flow length of the separation zone is 12.72mm. The reattachment shock wave angle is 54.845°, and the intensity is significantly smaller than the separation shock wave. According to frequency analysis, the separation shock wave movement is concentrated at 611Hz, which further strengthens the shock wave / boundary layer interference, causing more serious flow separation and having a serious impact on the supersonic flow field structure.

[0056] After excitation: 30 discharge areas are simultaneously excited by high-energy plasma, such as Figure 5 As shown in the figure, the discharge excitation generates 15 high-energy shock waves with a flow velocity of 539m / s, which means that every 17.6μs, a shock wave impacts the separation zone. After calculation and analysis, the angle of the separation shock wave after regulation is 39.946°, the angle with the wall is reduced by 1.639°, and the movement frequency is reduced to 509Hz. Figure 6 As shown in the figure, the plasma thermal effect produces a large-scale, slow-moving controlled hot air mass with a flow length of 341 mm, which is about ten times the length of the separation zone. The effective control time reaches 400 μs, which is twice the control time of a single set of exciters. The excitation also has a significant control effect on the reattached shock wave, and the morphology shows obvious bifurcation, thus changing the original morphology of the spatial interference zone. At this time, the low-frequency instability of the separation shock wave has been improved to a certain extent, and the influence on the adverse pressure gradient of the boundary layer has been greatly weakened, which improves the boundary layer flow separation phenomenon.

[0057] The description of the present invention is illustrative, but it is also applicable to other shock wave / boundary layer interference models. The present invention is proposed to provide a method for multi-channel plasma regulation of shock wave / boundary layer interference. A multi-channel high-energy plasma array is arranged in front of the interference area, and the strong impact effect and thermal effect of the high-energy plasma are used to produce a continuous impact disturbance effect on the wave system structure, and secondly, a hot air mass is formed to regulate the near-wall shock wave, thereby reducing the influence of the adverse pressure gradient on the boundary layer, improving the low-frequency instability of the shock wave, and slowing down the flow separation induced by the shock wave / boundary layer interference. This method gives full play to the excellent regulation effect of plasma, and at the same time achieves the control goals of suppressing flow separation and improving flow field stability, which is of great significance to improving supersonic shock wave / boundary layer interference.

Claims

1. A compression corner shock wave / boundary layer interference model, hereinafter referred to as "the model", wherein the design state Mach number is between Mach 1 and 5; the model surface is smooth and the flow direction is long; an artificial transition zone is installed upstream of the separation zone; and the model is characterized in that: The plasma actuator is processed by using insulating materials, and a U-shaped electrode cover is inserted into the insulating material; the U-shaped electrode cover is composed of a U-shaped conductive metal and an insulating sleeve just embedded therein, and the overall shape is a rectangular parallelepiped, and the upper surfaces of the U-shaped conductive metal and the insulating sleeve are flush; An array of grooves of the same size is opened on the upper surface of the insulating material to install a U-shaped electrode cover plate; the groove array is installed at the upstream position of the separation zone at the corner; two rows of grooves are arranged on the surface of the insulating material along the flow direction, and the two rows of grooves are symmetrical about the symmetry axis of the insulating material in the direction of expansion; each row of grooves includes a plurality of grooves evenly distributed along the flow direction, and the same spacing is maintained between adjacent grooves; each groove is arranged along the flow direction, so the line connecting the centers of the two ends of the U-shaped conductive metal is also along the flow direction; the two ends of the U-shaped conductive metal are exposed to the air; the upper surface of the U-shaped electrode cover plate is flush with the upper surface of the insulating material, and the upper surface of the insulating material is flush with the upper surface of the model; Holes are vertically punched downward on the surface of the insulating material extending outward from both ends of each row of grooves to set cylindrical stepped holes, and there are four cylindrical stepped holes in total in the two rows of grooves; the cylindrical stepped holes are composed of a large cylindrical hole and a small cylindrical hole, wherein the small cylindrical hole is close to the upper surface of the exciter and is used to install the cylindrical electrode; The large cylindrical hole is close to the lower surface of the exciter and needs to be completely opened so that the high-voltage wire connected to the cylindrical electrode can be placed from bottom to top.

2. The compression corner shock wave / boundary layer interference model according to claim 1, characterized in that: The model length is between 350mm-420mm and the width does not exceed 80mm; The slope deflection angle is between 20°-32°; The width of the artificial transition zone is between 6-12mm; The model making material has the characteristics of high strength, deformation resistance and wear resistance, and has no obvious protrusions and recesses; The plasma actuator is made of acrylic plastic material.

3. The compression corner shock wave / boundary layer interference model according to claim 1, characterized in that: The front-end electrode of the groove array shall not exceed 180 mm in front of the boundary layer separation zone at the corner.

4. The compression corner shock wave / boundary layer interference model according to claim 1, characterized in that: The length of a single U-shaped electrode cover is between 8-10mm, the width is between 1.5-2.5mm, and the depth is between 5-7mm, ensuring that the distance between adjacent electrodes is within the range of 0.3-0.8mm; A single U-shaped electrode cover is one line, and the total number of U-shaped electrode covers installed is more than 20 lines.

5. The compression corner shock wave / boundary layer interference model according to claim 1, characterized in that: Drill holes vertically downward on the surface of the insulating material extending 1-2 mm outward from both ends of each row of grooves; The diameter of the small cylindrical hole is about 1mm and the length is 4-6mm; the diameter of the large cylindrical hole is about 4mm; The high-voltage wires are sealed with high-temperature resistant insulating sealant and are externally connected to other circuit components.

6. The compression corner shock wave / boundary layer interference model according to claim 1, characterized in that: The electrical connections are as follows: A high-voltage pulse voltage source is used to apply positive and negative voltages to the U-shaped electrode cover plate respectively; the working voltage of the high-voltage pulse voltage source is 0 to 20 kV and the frequency is 0 to 5 kHz; Select any cylindrical electrode at both ends of each row of grooves as the positive end of the exciter, and the cylindrical electrode at the other end as the negative end of the exciter; the positive end of the high-voltage pulse voltage source is directly connected to the positive end of the exciter through the first diode, and the negative end of the high-voltage pulse voltage source is grounded; the DC voltage source, the current limiting resistor, and the capacitor are connected in sequence to form a loop, and the DC voltage source is connected to both ends of the capacitor; the positive end of the second diode is connected to the connection point of the current limiting resistor and the capacitor, the negative end of the second diode is connected to the positive end of the exciter, and the negative end of the exciter is grounded; when measuring, the oscilloscope test end is connected to the positive end of the exciter, and the negative end of the oscilloscope is grounded.

7. The compression corner shock wave / boundary layer interference model according to claim 6, characterized in that: The plasma discharge voltage is set to 20 kV, the discharge frequency is set to 500 Hz, the rising edge is 100 ns, the falling edge is 100 ns, and the pulse width is 100 ns; the current limiting resistor is 500 ohms.

8. The compression corner shock wave / boundary layer interference model according to any one of claims 1 to 7, characterized in that: The model is made of insulating PEEK material, with a design state of Mach number 2, a length of 378mm, a width of 80mm, a height of 52mm, a leading edge wedge angle of 10°, and a rear end compression corner angle of 24°. A boundary layer transition zone is arranged on the upper surface of the model along the span direction at a distance of 15mm from the leading edge of the model. The transition zone is 80mm long and runs through the span direction. The transition zone width is 10mm. The total length of the exciter is 146 mm, the width is 40 mm, and the height is 12 mm. 30 plasma discharge arrays are arranged on the short side symmetry axis, that is, 15 plasma discharge arrays are symmetrically arranged on the left and right sides of the short side symmetry axis, each plasma discharge array is a U-shaped electrode cover plate, the two ends of the 15 U-shaped electrode covers are in a straight line, and the straight line is parallel to the long side of the model, and the 15 U-shaped electrode covers are kept at the same distance; the electrode surface is flush with the exciter surface; the front end U-shaped electrode cover plate is 160 mm away from the compression corner, the spacing between adjacent U-shaped electrode covers along the flow direction is 0.5 mm, and the spacing between opposite U-shaped electrode covers along the span direction is 30 mm.

9. The compression corner shock wave / boundary layer interference model according to any one of claims 1 to 7, characterized in that: The working principle of this model is as follows: When the circuit is working, the exciter receives an instantaneous high-energy pulse from a high-voltage pulse voltage source, and the polarity of the cylindrical electrode changes drastically in an instant, resulting in the polarization of adjacent U-shaped conductive metals; since the U-shaped conductive metals are very close to each other, the metal polarities attract each other, so the polarization of one U-shaped conductive metal will cause the polarization of all U-shaped conductive metals in turn, thus forming a plasma excitation array; the electrodes at both ends of a single U-shaped conductive metal are blocked by an insulating sleeve, and a high-voltage potential difference is formed between the two metal ends of adjacent U-shaped conductive metals that are close to each other, and the distance scale is very small, which can easily break through the air medium to form a plasma path; since the plasma discharge channel is difficult to maintain for a long time in the air, a capacitor is required to release a large current to supplement the loss of the plasma discharge channel and enhance the energy release of the plasma in the air; the two diodes in the circuit are used to maintain the positive direction of the current to prevent the reverse direction from causing uncontrollable effects such as burning the circuit.

10. A method for multi-path plasma control of shock wave boundary layer interference, based on the compression corner shock wave / boundary layer interference model as claimed in claim 8, characterized in that: Before excitation: Under the design state of Mach 2, the compression corner shock wave / boundary layer interference model, the incoming flow is compressed to form a shock wave, that is, the model is in the rated working state; the forebody boundary layer develops into a turbulent boundary after passing through the transition zone. Due to the induction of the strong adverse pressure gradient of the shock wave, the incoming flow boundary layer no longer adheres to the wall, and flow separation occurs to form a separation shock wave and a reattachment shock wave; the shock wave foot moves back and forth in the intermittent zone; the intensity of the reattachment shock wave is significantly smaller than that of the separation shock wave, which further strengthens the shock wave / boundary layer interference, causing more serious flow separation and having a serious impact on the supersonic flow field structure; After excitation: 30 discharge areas are simultaneously subjected to high-energy plasma excitation, and the discharge excitation generates 15 high-energy shock waves; after the separation shock wave is regulated, the angle with the wall is reduced, and the movement frequency is reduced; the plasma thermal effect generates a large-scale, slow-moving controlled hot air mass, the flow length of which is about ten times the length of the separation zone, and the effective regulation time is twice the regulation time of a single set of exciters; the excitation also has a significant regulation effect on the reattachment shock wave, and the morphology shows obvious bifurcation, thereby changing the original morphology of the space interference zone; At this time, the low-frequency instability of the separation shock wave has been improved to a certain extent, the influence of the adverse pressure gradient on the boundary layer has been greatly weakened, and the boundary layer flow separation phenomenon has been improved.

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