A method for multi-path plasma control of shock wave boundary layer interference

Abstract

A compression corner shock wave / boundary layer interference model is provided, with a design state Mach number between Mach 1 and 5; an artificial transition zone is installed upstream of the separation zone; a U-shaped electrode cover is inserted into the interior of the insulating material; 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; two rows of grooves are arranged along the flow direction on the surface of the insulating material; each row of grooves includes multiple grooves evenly distributed along the flow direction, and the same spacing is maintained between adjacent grooves; cylindrical stepped holes are provided at the outward extensions of both ends of each row of grooves. A method for regulating shock wave boundary layer interference by multi-channel plasma is also provided. 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 generate a continuous impact disturbance effect on the wave system structure, forming 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.

Description

Technical Field

[0001] The present invention relates to the field of flow control technology, 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 supersonic flight. When flight speeds exceed Mach 1, the incoming airflow inevitably encounters irregularities such as corners and wedges on the aircraft's fuselage. Unable to smoothly pass through these areas, the forward flow is obstructed, while the velocity of the rearward flow remains constant. This causes compression of the gas within this area, forming multiple compression waves. Induced by pressure gradients, these multiple compression waves combine into a single wave, known as a shock wave. Shock waves cause significant changes in air pressure, often strongly interfering with other flow field structures and profoundly impacting the supersonic flow field.

[0003] The incoming flow and the wall of the aircraft form a boundary layer through viscous interaction. The mutual disturbance between the shock wave and the boundary layer is called shock wave / boundary layer interaction. Figure 1 As shown, the high-energy shock wave induces a strong adverse pressure gradient, reversing the flow direction within the boundary layer and forcing the incoming flow to be lifted away from the near-wall surface, forming a shear layer. The resulting series of compression waves converges into a separation shock wave. The separation zone is filled with low-energy airflow, forcing the boundary layer to bypass this area, forming a separation bubble there. The shear layer returns to the wall and decelerates, inducing a reattachment shock wave. The shock wave creates a strong wall-normal pressure gradient, causing a significant pressure jump and compression in the boundary layer during separation and reattachment. This causes a sharp increase in heat flux in the area, which can easily damage the surface materials of the aircraft. Furthermore, the shock wave undergoes a back-and-forth motion as the separation zone expands and contracts. This motion is often low-frequency, and therefore can resonate with critical components such as wings and air inlets, potentially having a fatal impact on the aircraft.

[0004] Plasma flow control has a natural advantage in controlling flow in shock wave / boundary layer interference due to its simple structure, wide bandwidth, fast response, and lack of moving parts. Currently, most experimental studies on plasma flow control, both domestically and internationally, are limited to the layout of a single set of exciters. When plasma is released from a single set of exciters, shock wave instabilities are reduced, but the instability frequency remains unchanged, and separation is not suppressed. The main reasons for this are: first, the control time is too short. Since the shock wave generated by the excitation flows at a very fast speed, the effective time scale is only around 200μs; second, the excitation scale is too small, and the control effect of a single shock wave is often not obvious. Therefore, innovatively expanding plasma excitation to a multi-channel array excitation to achieve a continuous excitation effect and extend the control time is feasible for improving shock wave / boundary layer interference. Summary of the Invention

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

[0006] The plasma actuator is made of insulating material, 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 that is embedded in it. 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 equal size is formed on the upper surface of the insulating material to accommodate a U-shaped electrode cover plate; the groove array is installed upstream of the separation zone at the corner; 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 axis of symmetry of the insulating material's span; each row of grooves includes multiple grooves evenly distributed along the flow direction, with adjacent grooves maintaining the same spacing; each groove is arranged along the flow direction, so that 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 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 mold;

[0008] Holes are punched vertically downward on the surface of the insulating material extending outward from both ends of each row of grooves to provide cylindrical stepped holes. There are four cylindrical stepped holes in total in the 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 to allow the high-voltage wires connected to the cylindrical electrode to be placed from bottom to top.

[0009] In one embodiment of the present invention,

[0010] The model length is between 350mm and 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 or recesses;

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

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

[0016] The front-end electrode of the groove array shall not exceed 180 mm 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] Punch 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 interaction model 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; the high-voltage pulse voltage source has an operating voltage of 0 to 20 kV and a frequency of 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; during measurement, 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 and is designed for Mach 2. It is 378mm long, 80mm wide, and 52mm high. The leading edge wedge angle is 10°, and the rear end compression angle is 24°. A boundary layer transition zone is arranged on the upper surface of the model along the span direction 15mm from the leading edge. The transition zone is 80mm long and runs through the span direction. The transition zone is 10mm wide.

[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 on a straight line, and the straight line is parallel to the long side of the model. The 15 U-shaped electrode covers maintain the same spacing; 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 interaction model is as follows:

[0033] When the circuit is operating, the exciter receives an instantaneous high-energy pulse from a high-voltage pulse voltage source, causing the polarity of the cylindrical electrode to change dramatically and instantly, resulting in the electrical 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 electrical polarization of one U-shaped conductive metal will sequentially cause the electrical polarization of all U-shaped conductive metals, 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 adjacent metal ends of the U-shaped conductive metals. The distance between them is very small, which can easily break through the air medium and 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 compensate for 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 out the circuit.

[0034] A method for multi-path plasma control 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: In the 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; 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 boundary layer no longer adheres to the wall, and flow separation occurs, forming 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, further strengthening the shock wave / boundary layer interference, causing more severe flow separation and having a serious impact on the supersonic flow field structure;

[0036] After excitation: high-energy plasma excitation is applied simultaneously to 30 discharge areas, and the discharge excitation generates 15 high-energy shock waves; after control, the separation shock wave has a smaller angle with the wall and a lower movement frequency; 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 control time is twice the control time of a single set of exciters; the excitation also has a significant control 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 has been 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 supersonic environments and the characteristics of high-altitude and high-speed flight environments, the present invention arranges a multi-channel plasma array in front of the separation zone, utilizing the strong shock effect and thermal effect of high-energy plasma to, on the one hand, produce a continuous shock disturbance effect 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 slowing down 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 the U-shaped electrode cover

[0040] Figure 3 Showing a 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 is shown;

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

[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, meeting 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 at the same time provide an installation platform for large-area plasma arrays. In order to make the shock wave / boundary layer interference and flow separation phenomena 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 ensure 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 with a width of between 6-12mm is installed upstream of the separation zone 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 into 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 embedded therein. 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] A groove array 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 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, symmetrical about the axis of symmetry along the span of the insulating material. Each row of grooves includes multiple grooves evenly distributed along the flow direction, with adjacent grooves maintaining the same spacing. 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 electrodes break through the air to form a plasma discharge circuit, thereby exciting the flow field.

[0047] Each U-shaped electrode cover is considered a circuit, and a total of at least 20 circuits should be installed to ensure that a large number of shock waves continuously impact the shock wave system. Each U-shaped electrode cover should be between 8-10mm long, 1.5-2.5mm wide, and 5-7mm deep. The spacing between adjacent electrodes should be within 0.3-0.8mm, ensuring that the time interval between adjacent shock waves reaching the separation zone is within 30μs to prevent the shock waves from reverting to their original form.

[0048] Cylindrical stepped holes are drilled vertically downward through the insulating material 1-2 mm outward from both ends of each row of grooves, creating a total of four cylindrical stepped holes across the two rows of grooves. These cylindrical stepped holes consist of two large and small cylindrical holes. The small cylindrical hole, located near the top surface of the actuator, has a diameter of approximately 1 mm and a length of 4-6 mm, and is used to mount the cylindrical electrode. The large cylindrical hole, located near the bottom surface of the actuator, has a diameter of approximately 4 mm and needs to be completely opened to allow for the upward placement of the high-voltage wires connected to the cylindrical electrodes. The high-voltage wires are sealed with high-temperature-resistant insulating sealant and are externally connected to other circuit components.

[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 operating voltage of the high-voltage pulse voltage source is 0-20kV and the frequency is 0-5kHz. The DC voltage source, current limiting resistor, and 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 end is connected to the positive end of the exciter, and the negative end of the oscilloscope is grounded.

[0050] When the circuit is operating, the exciter receives an instantaneous high-energy pulse from a high-voltage pulse voltage source, causing the polarity of the cylindrical electrode to change dramatically and instantly, resulting in the electrical polarization of adjacent U-shaped conductive metals. Because the U-shaped conductive metals are very close to each other, the metal polarities attract each other. Therefore, the electrical polarization of one U-shaped conductive metal will sequentially cause the electrical polarization of all U-shaped conductive metals, 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 adjacent metal ends of the U-shaped conductive metal. The distance between them is very small, which makes it very easy to break through the air medium and form a plasma path. Because the plasma discharge channel is difficult to maintain for a long time in air, a capacitor is required to release a large current to compensate for 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 forward direction of the current and prevent the reverse direction from causing uncontrollable effects such as burning the circuit.

[0051] In one embodiment of the present invention, Figure 4 shown. Figure 4 This is a detailed design diagram of the compression corner shock wave / boundary layer interaction model. The model is made of insulating PEEK material and is designed for Mach 2. It is 378mm long, 80mm wide, and 52mm high. The leading edge wedge angle is 10°, and the rear compression corner angle is 24°. A boundary layer transition zone is located 15mm from the leading edge, extending along the span of the upper surface. The transition zone is 80mm long, spanwise, and 10mm wide. Experimental results show that the laminar boundary layer transforms into turbulent flow after passing through the transition zone, creating a natural resistance to flow separation.

[0052] Grooves are opened along the flow direction on the upper surface of the model. The grooves maintain a certain distance from the front boundary layer transition zone and the rear slope, and are symmetrical about the flow axis of the upper surface of the model. The size of the grooves is just enough to accommodate the exciter. The exciter is installed in the groove by screws, and is in close contact with the mounting 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 cover plates are on a straight line, and the straight line is parallel to the long side of the model. The 15 U-shaped electrode cover plates maintain 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 was set to 20 kV, the discharge frequency to 500 Hz, the rising edge to 100 ns, the falling edge to 100 ns, and the pulse width to 100 ns. After the capacitor was fully charged, it continued to provide discharge energy to the exciter. To prevent damage to the charging circuit, a 500 ohm current-limiting resistor was inserted into the loop. The diode provided unidirectional current, ensuring stable operation of the plasma discharge exciter.

[0054] During the implementation of the present invention, a plasma exciter is used to arrange a multi-channel high-energy plasma array in front of the interference zone. The strong impact effect and thermal effect of the high-energy plasma are utilized to, firstly, produce a continuous impact disturbance effect on the wave system structure, and secondly, 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: The compression corner shock wave / boundary layer interaction model operates at Mach 2, where the incoming flow is compressed to form a shock wave. This indicates the model is operating at rated speed. The forebody boundary layer develops into a turbulent boundary after passing through the transition zone. Induced by the strong adverse pressure gradient of the shock wave, the incoming boundary layer no longer adheres to the wall, causing flow separation and the formation of a separation shock wave and a reattachment shock wave. The separation shock wave has an angle of 41.585°, with the shock foot moving back and forth within the intermittent zone. The flow-wise length of the separation zone is 12.72 mm. The reattachment shock wave has an angle of 54.845° and is significantly weaker than the separation shock wave. Frequency analysis shows that the separation shock wave motion is concentrated at 611 Hz, further intensifying the shock wave / boundary layer interaction and causing more severe flow separation, which has a significant 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 motion frequency is reduced to 509Hz. Figure 6 As shown, the plasma thermal effect generates a large, slow-moving controlled hot mass with a flow length of 341 mm, approximately ten times the length of the separation zone. The effective control time reaches 400 μs, twice the control time of a single set of actuators. The excitation also has a significant control effect on the reattachment shock wave, resulting in a distinct bifurcation of its morphology, thus altering the original shape of the spatial interference zone. The low-frequency instability of the separation shock wave is somewhat ameliorated, and its influence on the adverse pressure gradient in the boundary layer is significantly reduced, improving the separation of the boundary layer flow.

[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, in which a multi-channel high-energy plasma array is arranged in front of the interference zone, and the strong shock effect and thermal effect of the high-energy plasma are utilized to produce a continuous shock disturbance effect on the wave system structure, and secondly, 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. This method gives full play to the excellent regulation effect of the plasma, while achieving the control goals of suppressing flow separation and improving the stability of the flow field, which is of great significance to improving supersonic shock wave / boundary layer interference.

Claims

1. A compression corner shock wave / boundary layer interaction model, hereinafter referred to as the "model," having a design Mach number between Mach 1 and 5; a smooth surface and a long flow direction; and an artificial transition zone installed upstream of the separation zone; characterized in that: The plasma actuator is made of insulating material, 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 that is embedded in it. 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 equal size is formed on the upper surface of the insulating material to accommodate a U-shaped electrode cover plate; the groove array is installed upstream of the separation zone at the corner; 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 axis of symmetry of the insulating material's span; each row of grooves includes multiple grooves evenly distributed along the flow direction, with adjacent grooves maintaining the same spacing; each groove is arranged along the flow direction, so that 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 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 mold; Holes are punched vertically downward on the surface of the insulating material extending outward from both ends of each row of grooves to form cylindrical stepped holes. There are four cylindrical stepped holes in total in the two rows of grooves. The cylindrical stepped holes consist of a large and a small cylindrical hole, of which 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, wherein: The model length is between 350mm and 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 or recesses; The plasma actuator is made of acrylic plastic material.

3. The compression corner shock wave / boundary layer interference model according to claim 1, wherein: 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, wherein: 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, wherein: Punch 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, wherein: 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; the high-voltage pulse voltage source has an operating voltage of 0 to 20 kV and a frequency of 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; during measurement, 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, wherein: 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 and is designed for Mach 2. It is 378mm long, 80mm wide, and 52mm high. The leading edge wedge angle is 10°, and the rear end compression angle is 24°. A boundary layer transition zone is arranged on the upper surface of the model along the span direction 15mm from the leading edge. The transition zone is 80mm long and runs through the span direction. The transition zone is 10mm wide. 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 on a straight line, and the straight line is parallel to the long side of the model. The 15 U-shaped electrode covers maintain the same spacing; 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 operating, the exciter receives an instantaneous high-energy pulse from a high-voltage pulse voltage source, causing the polarity of the cylindrical electrode to change dramatically and instantly, resulting in the electrical 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 electrical polarization of one U-shaped conductive metal will sequentially cause the electrical polarization of all U-shaped conductive metals, 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 adjacent metal ends of the U-shaped conductive metals. The distance between them is very small, which can easily break through the air medium and 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 compensate for 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 out 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 according to claim 8, characterized in that: Before excitation: In the 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; 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 boundary layer no longer adheres to the wall, and flow separation occurs, forming 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, further strengthening the shock wave / boundary layer interference, causing more severe flow separation and having a serious impact on the supersonic flow field structure; After excitation: High-energy plasma excitation is applied simultaneously to 30 discharge regions, generating 15 high-energy shock waves. After control, the separation shock wave has a smaller angle with the wall and a lower frequency of motion. The plasma thermal effect generates a large-scale, slow-moving controlled hot air mass with a flow length approximately ten times that of the separation zone. The effective control time is twice that of a single set of exciters. The excitation also has a significant control effect on the reattachment shock wave, with a distinct bifurcation in its morphology, 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, 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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