Grating type noise reduction circular seam type pressure regulating valve for wind tunnel

Abstract

The invention discloses a grid type noise reduction circular seam type pressure regulating valve device for a wind tunnel, and belongs to the technical field of fluid regulation and control equipment. The device comprises an outer conical cylinder, an inner conical cylinder, a grating type pressure regulating molded surface cone, a piston, a servo driving device, a diagonal draw bar and a flow guide ring. The inner conical cylinder is arranged in the outer conical cylinder, and an airflow circulation area is formed between the outer conical cylinder and the inner conical cylinder. The grating type pressure adjusting molded surface cone is used for adjusting the pressure of a flow field, and the two ends of the diagonal draw bar are hinged to the servo driving device and the piston respectively. The piston is in sliding connection with the inner cone cylinder through the servo driving device, so that the axial displacement of the piston and the grating type pressure regulating profile cone is changed, the channel sectional area of the piston and the grating type pressure regulating profile cone is changed, flow field pressure regulation is achieved, noise can be effectively reduced, gas leakage is reduced, and wind tunnel resonance is avoided.

Description

Technical Field

[0001] The invention relates to a grid-type noise-reducing annular gap-type pressure-regulating valve for a wind tunnel, belonging to the technical field of fluid control equipment. Background Art

[0002] Wind tunnel testing, as an important aerodynamic testing method, is widely used in aerospace, automotive, construction, and other fields. Regulating the pressure of the airflow within the wind tunnel is crucial. Conventional pressure-regulating valves, while ensuring accuracy and stability, can also lead to problems such as turbulent airflow, excessive noise, and structural vibration.

[0003] Currently, conventional industrial-grade pressure regulating valves have a flow regulation accuracy of only 1-5%, and their noise levels can reach over 170dB, making them difficult to meet the precise pressure regulation and low noise requirements of wind tunnel experiments. Traditional wind tunnel pressure regulating valves often use an annular gap pressure regulating structure, but these valves suffer from drawbacks such as airflow separation, high valve noise, and seal leakage, making them incapable of achieving the precise flow field pressure regulation and low noise requirements. Summary of the Invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the existing technology, and to propose a grid-type noise-reducing annular gap pressure regulating valve for wind tunnels. Through the flow stabilization design of the grid-type pressure regulating profile cone, the pressure regulation design of the servo drive device, and the shock absorption design of the shock absorber, precise regulation of the flow field pressure in the wind tunnel experiment is achieved.

[0005] The technical solution of the present invention is:

[0006] A grid-type noise-reducing annular gap-type pressure-regulating valve for a wind tunnel, comprising an outer cone, an inner cone, a grid-type pressure-regulating profile cone, a piston, a servo drive device, a horizontal vibration damper, a vertical vibration damper, a diagonal tie rod, and a guide ring;

[0007] The inner cone is arranged inside the outer cone, and an air flow area is formed between the outer cone and the inner cone;

[0008] The grid-type pressure-regulating cone inlet is connected to the outer cone, and the outlet is connected to the guide ring, for regulating the flow field pressure;

[0009] The piston is arranged between the inner cone and the grid-type pressure-regulating profile cone; the piston is integrally formed of a circular ring, longitudinal ribs and transverse ribs, and a horizontal vibration damper and a vertical vibration damper are respectively arranged in the multiple concave cavities formed by the longitudinal ribs and the transverse ribs. The horizontal vibration damper is used to reduce the axial horizontal vibration of the piston, and the vertical vibration damper is used to reduce the vertical vibration of the piston;

[0010] The servo drive device is fixed in the inner cone;

[0011] The two ends of the inclined tie rod are respectively hingedly connected to the servo drive device and the piston;

[0012] The piston is slidably connected to the inner cone through a servo drive device, so that the axial displacement of the piston and the grid-type pressure-regulating surface cone changes, causing the channel cross-sectional area of the piston and the grid-type pressure-regulating surface cone to change, thereby realizing the regulation of the flow field pressure.

[0013] Furthermore, the servo drive device includes a servo hydraulic cylinder, a spline shaft, a spline sleeve, a support and a displacement sensor;

[0014] The spline shaft is fixed to the front inner side of the inner cone through a support, and the spline shaft and the spline sleeve form a ball spline; one end of the inclined rod is hinged to the outer wall of the spline sleeve, and the other end is connected to the piston;

[0015] The servo hydraulic cylinder is arranged in the middle of the inner side of the inner cone, and the end of the hydraulic rod of the servo hydraulic cylinder is fixedly connected to the spline sleeve; the servo hydraulic cylinder drives the spline sleeve to slide back and forth relative to the spline shaft, thereby driving the inclined rod to drive the piston to move axially;

[0016] The displacement sensor is arranged in parallel with the servo hydraulic cylinder to monitor the displacement of the piston movement.

[0017] Furthermore, the servo hydraulic cylinder is a double-acting servo hydraulic cylinder, which adopts a double closed-loop PID servo control strategy based on valve characteristics, with the outer loop as total pressure and the inner loop as valve position, and uses a parabolic speed curve to optimize the valve core switch car.

[0018] Furthermore, the piston end is provided with a main seal and a secondary seal, and the main seal and the secondary seal are sealed by inflation; the main seal is a double-layer structure with a valve core one-way valve check inflation port, the outer layer is a T-shaped structure with a draft angle, and the inner layer is an inflation O-ring structure; the secondary seal is a multi-channel V-shaped structure.

[0019] Furthermore, the horizontal vibration absorber and the vertical vibration absorber are permanent magnet adjustable magnetorheological dampers, or are viscous fluid dampers, magnetorheological dampers, or viscous shear dampers.

[0020] Furthermore, the guide ring is connected to the grid-type pressure-regulating cone outlet. The cross section of the guide ring is a structure of arc and tangent. The outlet tangent angle is the same as the angle of the external large-angle diffusion section connected to the rear end, and the expansion angle is between 30 and 90 degrees.

[0021] Furthermore, the grid of the grid-type pressure-regulating cone has a circumferential interval angle of less than 15°, and the flow channel is evenly divided into small channels by the grid to avoid circumferential movement of the airflow; the side of the grid that contacts the piston radially has a wear-resistant slider lubricated with graphite, which guides the piston.

[0022] Furthermore, the grid is composed of multiple layers of sintered metal mesh blocks with a mesh size range of 10 to 300 meshes; the noise reduction frequency of the sintered metal mesh block noise reduction arc plate is 0 to 40,000 Hz, and the air permeability is 30% to 100%.

[0023] Furthermore, the diagonal tie rod is a rod with spherical hinged ear seats at both ends, and the thread direction of the spherical hinged ear seat is opposite to that of the diagonal tie rod; one end is connected to the piston through a spherical hinged ear seat with trapezoidal thread self-locking, and the other end is hinged to the spline sleeve through the spherical hinged ear seat, which has self-locking and length adjustment functions.

[0024] Furthermore, the profile of the outer cone is designed to be a cylinder-cone-cylinder structure, the cone angle of the outer cone is less than 30°, and the cone angle of the inner cone is less than 60°.

[0025] The advantages of the present invention compared with the prior art are:

[0026] (1) Flow stabilization measures: The present invention sets a grid-type pressure regulating surface cone on the pressure regulating surface to reduce airflow pulsation and improve the uniformity of the inlet airflow; there is no support at the outlet to avoid structural vibration caused by airflow separation.

[0027] (2) Precise Pressure Regulation: The present invention uses a servo pump to control a servo drive device consisting of a servo hydraulic cylinder, a hydraulic rod, and a displacement sensor. This drives a splined sleeve to drive the diagonal tie rod, which ultimately drives the axial movement of the piston. By varying the axial displacement of the piston and the pressure-regulating profile cone, the cross-sectional area of the channel is precisely adjusted, achieving precise regulation of the flow field pressure.

[0028] (3) Vibration reduction design: The present invention designs horizontal and vertical vibration dampers for the piston to avoid axial and radial vibration of the piston and improve the stability of the pressure regulating valve.

[0029] (4) Bidirectional sealing structure: The present invention adopts a bidirectional sealing structure of a V-shaped secondary seal and a convex main seal, and uses pipeline gas for inflation sealing to avoid overpressure leakage and achieve rapid pipeline on-off sealing.

[0030] (5) Servo hydraulic control: The servo pump and servo hydraulic valve designed in the present invention perform coarse and fine control on the flow of the servo hydraulic cylinder, adopt a double closed-loop PID control strategy, optimize the switching process of the valve core through the parabolic speed curve, avoid the impact of the valve core on the valve structure, and extend the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0032] Figure 1 This is a schematic cross-sectional view of the overall structure of a pressure regulating valve device according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the overall structure of the pressure regulating valve device of the embodiment of the present invention.

[0034] Figure 3 This is a schematic structural diagram of a piston and a shock absorber according to an embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram of the adjacent relationship structure of the grid-type pressure-regulating cones according to an embodiment of the present invention;

[0036] Figure 5 This is a schematic cross-sectional view of a main seal with an inflatable seal of a valve core according to an embodiment of the present invention;

[0037] Figure 6 This is a structural schematic diagram of the relative position relationship between the inclined tie rod and the hydraulic cylinder support according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0039] The present invention proposes a grid-type noise reduction annular gap type pressure regulating valve for wind tunnel, such as Figure 1 、 Figure 2 As shown, it includes an outer cone 1, an inner cone 17, a grid-type pressure-regulating profile cone 3, a piston 8, a servo drive device, and a guide ring 4.

[0040] The outer cone 1 is composed of an inlet flange, a circular ring, a conical ring, a circular ring, an arc ring, and an outlet flange of a standard gas pressure-bearing flange structure. The inlet and outlet flanges are determined based on the flow rate and pressure regulation characteristics of the sub-span super wind tunnel, and preferably have similar diameters.

[0041] The inlet of the grille-type pressure-regulating profile cone 3 is connected to the outlet flange of the outer cone 1, and the outlet is connected to the guide ring. The inner surface of the grille-type pressure-regulating profile cone 3 combines with the arc ring of the outer cone 1 to form a pneumatic pressure-regulating profile combining an arc and multi-segment exponential structure. The grille of the pressure-regulating profile cone evenly divides the flow path into small channels, preventing circumferential airflow.

[0042] The guide ring 4 is connected to the outlet of the grid-type pressure-regulating cone 3. Its cross-section is a structure of circular arcs and tangents, utilizing the fluid's wall adhesion effect to reduce flow separation. The outlet tangent angle is the same as that of the external high-angle diffuser connected to the rear end, with the expansion angle ranging from 30 to 90 degrees, preferably 45 degrees.

[0043] Inner cone 17 is positioned within outer cone 1, forming a flow area with the outer cone 1. The cone angle of outer cone 1 is less than 30°, ensuring smooth airflow within the channel. Outer cone 1 is connected to inner cone 17 via an even number of support ribs 18 (six in this example). Inner cone 17 has a conical-cylindrical ring structure, and the cone angle of inner cone 20 is less than 60°. The combined flow area is equivalent to the inlet area.

[0044] A piston 8 is mounted on the inner end of the inner cone 17, slidably connected to the inner cone 17 via a servo drive. Positioned between the inner cone 17 and the grid-type pressure-regulating profile cone 3, the piston 8's axial displacement changes the cross-sectional area of the passageway between the piston 8 and the grid-type pressure-regulating profile cone 3, enabling precise regulation of the flow field pressure. The radial contact surface of the grid with the piston is guided by a wear-resistant beryllium bronze slider lubricated with graphite. The sidewalls of the grid feature a microporous sound-absorbing structure with a diameter of less than 0.2 mm. The grid can be composed of multiple layers of sintered metal mesh with a mesh size ranging from 10 to 300. The sintered metal mesh noise-reducing arc plates have a noise reduction frequency of 0 to 40,000 Hz and an air permeability of 30% to 100%.

[0045] Specifically, the servo drive device includes a servo hydraulic cylinder 14 (including a double-acting double-output hydraulic rod), a spline sleeve 19 and a displacement sensor 11. The servo hydraulic cylinder 14 is fixed to the middle of the inner cone 17 through a hydraulic cylinder support 15. Figure 6 As shown, the hydraulic cylinder support 15 is defined by guide grooves corresponding in number and position to the diagonal tie rods 16. Driven by the servo hydraulic cylinder 14, it drives the splined sleeve 19, diagonal tie rods 16, and piston 8 in linear reciprocating motion. The hydraulic cylinder 14, in parallel with the displacement sensor 11, drives the splined sleeve 19 anti-torsion assembly, and multiple sets of diagonal tie rods 16 drive the piston 8, achieving linear pressure change in the pressure regulating valve area. The staggered arrangement of the hydraulic cylinder 14, displacement sensor 11, splined sleeve 19, diagonal tie rods 16, and piston 8 utilizes three-dimensional space to reduce the axial distance between the pressure regulating valves and lower construction costs. The tapered ring of the hydraulic cylinder support 15 forms an X-shaped arrangement with the diagonal tie rods 16. The diagonal tie rods 16 can be of various shapes to match the hydraulic cylinder support 15.

[0046] In this embodiment, the grid-shaped pressure-regulating cone 3 is used to adjust the flow field pressure, and the servo hydraulic cylinder 14 is used to drive the piston 8 for precise pressure regulation. The hydraulic rod of the servo hydraulic cylinder 14 is a double-acting servo hydraulic cylinder. It employs dual servo hydraulic valves for coarse and fine flow control, achieving precise pressure regulation and emergency shutdown functions. A dual closed-loop PID servo control strategy, with the outer loop representing total pressure and the inner loop representing valve position, is based on valve characteristics. A parabolic velocity curve is employed to optimize the valve spool's opening and closing behavior. This precise PID control strategy adjusts the valve position, optimizing the valve spool's opening and closing process and preventing rapid impact damage to the valve structure. The servo hydraulic cylinder 14 and the displacement sensor 11 are arranged in parallel to form a servo drive device. One end of the hydraulic rod of the servo hydraulic cylinder 14 is connected to a splined sleeve 19. The displacement sensor 11 is fixed to the base of the servo hydraulic cylinder 14 at one end and connected to the splined sleeve 19 at the other end. The displacement sensor 11 is arranged in parallel with the servo hydraulic cylinder 14. Preferably, the telescopic rod of the displacement sensor 11 is located within the hydraulic cylinder sleeve to protect it from airflow and monitor the piston position in real time.

[0047] A support 21 is fixed to the air intake front end of the inner cone 17. A splined shaft 20 is fixed to the support 21. A splined sleeve 19 is slidably connected to the splined shaft 20. The splined sleeve 19 is fixedly connected to the end of the hydraulic rod of the servo hydraulic cylinder 14. The servo hydraulic cylinder 14 drives the splined sleeve 19 to slide back and forth relative to the splined shaft 20. The inner cone 17 is also equipped with a metal protective tube 22 for the hydraulic oil supply line of the hydraulic cylinder. The hydraulic rod protective covers 12 and 13 of the servo hydraulic cylinder 14 prevent damage to the hydraulic lines due to airflow.

[0048] Several diagonal tie rods 16 are hingedly connected to the outer wall of the splined sleeve 19. The other ends of the diagonal tie rods 16 are hingedly connected to the piston 8. A servo drive device consisting of a servo hydraulic cylinder 14 and a displacement sensor 11 axially drives the splined sleeve 19, driving the diagonal tie rods 16 and ultimately driving the axial movement of the piston 8. The displacement sensor 11 provides real-time feedback on the axial position of the piston 8.

[0049] In this embodiment, the diagonal rod 16 is a rod with spherical hinged ears at both ends. The ears are connected to the rod by a trapezoidal thread. The spherical hinged ears at both ends are opposite to the threads of the diagonal rod and have self-locking and length adjustment functions. There are an even number of them along the circumference (6 in this embodiment), one end is connected to the piston 8 through the diagonal rod support 23, and the other end is connected to the spline sleeve 19.

[0050] The servo hydraulic cylinder 14 drives the spline sleeve 19 to slide back and forth relative to the spline shaft through the hydraulic rod. The spline sleeve 19 drives the movement between the diagonal tie rod 16 and the piston 8. The displacement sensor 11 with real-time feedback accurately adjusts the position of the piston, thereby adjusting the channel cross-sectional area of the pressure-regulating profile cone and achieving precise control of the flow field pressure.

[0051] In this embodiment, the grilles of the grid-type pressure-regulating cone 3 are spaced at an 8° circumferential angle to stabilize flow and reduce airflow pulsation. The flow field outlet is free of support to prevent structural vibration caused by flow separation. The total cross-sectional area of the grilles of the grid-type pressure-regulating cone 3 is equivalent to the total cross-sectional area of the support ribs 18.

[0052] In this embodiment, the spline sleeve 19 is provided to avoid circumferential vibration of the piston 8. The piston 8 is preferably a cast aluminum structure to reduce weight. It is formed by a ring, longitudinal ribs and transverse ribs in one piece. When large structures exceed the processing capacity of cast aluminum, ordinary steel can be used. The outlet end is connected to the valve core inflation ring 7 uniformly distributed with one-way tiny air holes, and clamped with the main sealing cover plate 6 to achieve valve core sealing. The main seal 5 is a double-layer sealing structure of an inflation ring and a convex structure with a draft angle. The outer layer is a T-shaped structure with a draft angle, and the inner layer is an inflation O-ring structure, such as Figure 5 As shown, it is equipped with a pressure monitoring device and a tire pressure detector (similar to the structure of a car pneumatic tire).

[0053] The spline sleeve 19 and the spline shaft 20 form a high-torque ball spline. The rolling friction reduces the friction coefficient by about one order of magnitude compared to the sliding friction, thereby improving the torsional resistance of the piston 8 and preventing the piston 8 from vibrating circumferentially.

[0054] In order to reduce valve noise, especially at high flow rates, a horizontal damper 9 and a vertical damper 10 are provided in the cavity formed by the longitudinal and transverse ribs of the piston 8, as shown in FIG. Figure 3 As shown, multiple dampers are evenly distributed along the circumference. Horizontal dampers 9 are used to reduce the axial horizontal vibration of piston 8, while vertical dampers 10 are used to reduce the vertical vibration of piston 8. Horizontal and vertical dampers 9 and 10 are permanent magnet-adjustable magnetorheological dampers, or viscous fluid dampers, magnetorheological dampers, or viscous shear dampers, which can effectively reduce vibration and noise in the wind tunnel.

[0055] In this embodiment, the end of the piston 8 is provided with a primary seal 5 and a secondary seal 2, and the primary seal 5 and the secondary seal 2 of the piston 8 are inflated to achieve an inflatable seal. The high-pressure gas is used to enhance the sealing performance and prevent leakage.

[0056] like Figure 4 As shown, the secondary seal 2 has a V-shaped structure, while the primary seal 5 is a convex structure with an inflatable port and an inclined surface. High-pressure gas passes through the inflatable port, ensuring a tighter fit between the secondary and primary seals 2 and 5, preventing overpressure leakage. In this embodiment, the cover plate 6 of the secondary seal 2 and the primary seal cover are both removable and replaceable in circumferential sections. This allows for quick on / off sealing of pipelines. Multiple primary and secondary seals 5 and 2 can be arranged to enhance sealing redundancy and safety.

[0057] The invention avoids the vibration of the pressure regulating valve and realizes the precise closed-loop control of the flow field pressure. Necessary mechanical limits are designed at both ends of the piston and the spline sleeve to ensure movement within the effective stroke.

[0058] The entire device is equipped with necessary supports and lifting lugs for easy installation and storage.

[0059] The present invention aims to solve the problems that the existing wind tunnel pressure regulating valve has no flow stabilization measures at the inlet and the valve core is supported at the outlet, resulting in poor inlet airflow uniformity and large flow separation caused by outlet support interference. The present invention arranges a grid-type pressure regulating profile cone 3 for flow stabilization at the inlet and no support separation at the outlet to ensure a stable flow field.

[0060] This invention uses a servo hydraulic cylinder to drive a high-torque ball spline servo drive, which in turn axially drives a spline sleeve to drive the diagonal tie rod, ultimately driving the axial movement of the piston. Rolling friction replaces sliding friction, improving the piston's torsional resistance. The shock absorber prevents buckling of the diagonal tie rod and achieves vibration reduction. A displacement sensor provides real-time feedback on the piston's axial position. Precise regulation of flow field pressure is achieved by varying the cross-sectional area of the passageway between the piston and the pressure-regulating cone, caused by changes in their axial displacement.

[0061] The piston secondary seal of this invention features a V-shaped structure, while the primary seal is a convex, beveled structure with a valve core inflation port. The inflation port allows the secondary and primary seals to fit more closely to the sealing surface, preventing overpressure leakage. Multiple seals can be combined to form a bidirectional sealing structure, enabling rapid on / off sealing of pipelines.

[0062] The pressure regulating valve drive device of the present invention adopts a dual servo hydraulic valve driven by a servo pump to achieve coarse and fine flow control to realize precise pressure regulation and emergency shutdown functions. Based on the valve characteristics, the outer ring is the total pressure and the inner ring is the valve position. The double closed-loop PID servo control strategy uses a parabolic speed curve to optimize the valve core switching car, avoiding the valve core from quickly impacting and damaging the valve structure.

[0063] The method of using the super wind tunnel large-diameter grid-type noise reduction annular gap type pressure regulating valve includes:

[0064] The two ends of the grid-type pressure-regulating profile cone 3 are respectively connected to the outer cone 1 and the guide ring 4, and the inner cone 17 and the outer cone 1 form a fluid flow area;

[0065] The servo drive device axially drives the spline sleeve 19 to drive the inclined rod 16 and ultimately drives the piston 8 to move axially. The displacement sensor 11 is arranged in parallel with the hydraulic cylinder 14 to provide real-time feedback on the axial position of the piston 8. The change in the axial displacement of the piston 8 and the grid-type pressure-regulating profile cone 3 causes the change in the channel cross-sectional area of the piston 8 and the pressure-regulating profile cone 3 to achieve precise regulation of the flow field pressure.

[0066] The grid of the grid-type pressure-regulating cone 3 stabilizes the flow and reduces airflow pulsation. There is no support at the flow field outlet to avoid structural vibration caused by flow separation. The spline sleeve 19 prevents the piston 8 from vibrating circumferentially. The shock absorbers 9 and 10 prevent the piston from vibrating radially and axially and achieve vibration reduction. The piston main seal 5 and the secondary seal 2 use inflation to achieve inflation sealing and have tire pressure monitoring function.

[0067] This invention can adjust flow field pressure in real time according to the requirements of wind tunnel experiments. It exhibits excellent fluid dynamics and structural durability, ensuring precise control and stable operation, especially under high-frequency regulation. Through simple adjustments and control, it can precisely adjust the flow field pressure distribution to meet the needs of different wind tunnel experiments. During high-flow rate regulation, it effectively reduces mechanical shock and noise from the valve. The vibration damping device, coupled with the piston, mitigates vibrations caused by rapid piston movement and airflow impact, thereby ensuring the long-term stability and reliability of the device.

[0068] The above-described embodiments are only preferred specific implementations of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A grid-type noise reduction annular gap type pressure regulating valve for wind tunnel, characterized in that: It includes an outer cone, an inner cone, a grid-type pressure-regulating profile cone, a piston, a servo drive device, a horizontal vibration absorber, a vertical vibration absorber, a diagonal tie rod and a guide ring; The inner cone is arranged inside the outer cone, and an air flow area is formed between the outer cone and the inner cone; The grid-type pressure-regulating cone inlet is connected to the outer cone, and the outlet is connected to the guide ring, for regulating the flow field pressure; The piston is arranged between the inner cone and the grid-type pressure-regulating profile cone; the piston is integrally formed of a circular ring, longitudinal ribs and transverse ribs, and a horizontal vibration damper and a vertical vibration damper are respectively arranged in the multiple concave cavities formed by the longitudinal ribs and the transverse ribs. The horizontal vibration damper is used to reduce the axial horizontal vibration of the piston, and the vertical vibration damper is used to reduce the vertical vibration of the piston; The servo drive device is fixed in the inner cone; The two ends of the inclined tie rod are respectively hingedly connected to the servo drive device and the piston; The piston is slidably connected to the inner cone through a servo drive device, so that the axial displacement of the piston and the grid-type pressure-regulating surface cone changes, causing the channel cross-sectional area of the piston and the grid-type pressure-regulating surface cone to change, thereby realizing the regulation of the flow field pressure.

2. The grid-type noise reduction annular gap type pressure regulating valve for wind tunnel according to claim 1, characterized in that: The servo drive device includes a servo hydraulic cylinder, a spline shaft, a spline sleeve, a support and a displacement sensor; The spline shaft is fixed to the front inner side of the inner cone through a support, and the spline shaft and the spline sleeve form a ball spline; one end of the inclined rod is hinged to the outer wall of the spline sleeve, and the other end is connected to the piston; The servo hydraulic cylinder is arranged in the middle of the inner side of the inner cone, and the end of the hydraulic rod of the servo hydraulic cylinder is fixedly connected to the spline sleeve; the servo hydraulic cylinder drives the spline sleeve to slide back and forth relative to the spline shaft, thereby driving the inclined rod to drive the piston to move axially; The displacement sensor is arranged in parallel with the servo hydraulic cylinder to monitor the displacement of the piston movement.

3. The grid-type noise reduction annular gap type pressure regulating valve for wind tunnel according to claim 2, characterized in that: The servo hydraulic cylinder is a double-acting servo hydraulic cylinder, which adopts a double closed-loop PID servo control strategy based on valve characteristics, with the outer loop as the total pressure and the inner loop as the valve position, and uses a parabolic speed curve to optimize the valve core switch vehicle.

4. The grid-type noise reduction annular gap type pressure regulating valve for wind tunnel according to claim 1, characterized in that: The piston end is provided with a main seal and a secondary seal, and the main seal and the secondary seal are sealed by inflation; the main seal is a double-layer structure with a valve core one-way valve check inflation port, the outer layer is a T-shaped structure with a draft angle, and the inner layer is an inflation O-ring structure; the secondary seal is a multi-channel V-shaped structure.

5. The grid-type noise reduction annular gap type pressure regulating valve for wind tunnel according to claim 1, characterized in that: The horizontal vibration absorber and the vertical vibration absorber are permanent magnet adjustment type magnetorheological dampers, or are viscous fluid dampers, magnetorheological dampers, and viscous shear dampers.

6. The grid-type noise reduction annular gap type pressure regulating valve for wind tunnel according to claim 1, characterized in that: The guide ring is connected to the grid-type pressure-regulating cone outlet. The cross section of the guide ring is a structure of arc and tangent. The outlet tangent angle is the same as the angle of the external large-angle diffusion section connected to the rear end, and the expansion angle is between 30 and 90 degrees.

7. The grid-type noise reduction annular gap type pressure regulating valve for wind tunnel according to claim 1, characterized in that: The grid of the grid-type pressure-regulating cone has a circumferential interval angle of less than 15°. The grid evenly divides the flow channel into small channels to avoid circumferential movement of the airflow. The radial side of the grid in contact with the piston has a wear-resistant slider lubricated with graphite, which guides the piston.

8. The grid-type noise reduction annular gap type pressure regulating valve for wind tunnel according to claim 7, characterized in that: The grid is composed of multiple layers of sintered metal mesh blocks with a mesh size range of 10 to 300 meshes; the noise reduction frequency of the sintered metal mesh block noise reduction arc plate is 0 to 40,000 Hz, and the air permeability is 30% to 100%.

9. The grid-type noise reduction annular gap type pressure regulating valve for wind tunnel according to claim 1, characterized in that: The diagonal tie rod is a rod with spherical hinged ears at both ends. The threads of the spherical hinged ears and the diagonal tie rod are selected in opposite directions. One end is connected to the piston through a spherical hinged ear with trapezoidal thread self-locking, and the other end is hinged to the spline sleeve through the spherical hinged ear, which has self-locking and length adjustment functions.

10. The grid-type noise reduction annular gap type pressure regulating valve for wind tunnel according to claim 1, characterized in that: The profile of the outer cone is designed to be a cylinder-cone-cylinder structure, the cone angle of the outer cone is less than 30°, and the cone angle of the inner cone is less than 60°.

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