Experimental device and method for realizing hydrodynamic stealth of bluff bodies through active flow control

Abstract

The present invention discloses an experimental device and method for realizing the hydrodynamic stealth of a bluff body by active flow control, which belongs to the field of fluid mechanics and flow control; the experimental device comprises a water tank, a single-degree-of-freedom vibration module, an active control module, a speed measurement module, and an intelligent body module, wherein the water tank provides a fluid environment for the experiment; the bluff body model of the single-degree-of-freedom vibration module is placed in water and can perform simulated motion in the water; the active control module comprises a generator and a water pump, wherein the generator is a jet hole arranged on the surface of the bluff body model, and the water pump is connected to the generator through a conduit; the speed measurement module is used to collect and feedback flow field information; the intelligent body module receives the flow field information fed back by the speed measurement module, calculates control parameters in real time, and controls the pumping and spraying actions and flow rate of the water pump in real time. When the bluff body model moves in the fluid, the flow field will change significantly, and the active flow control utilizes the generator to pump / absorb fluid in the near-wall area to affect the development of the shear layer, thereby effectively changing the morphology of the downstream wake vortex.

Description

Technical Field

[0001] The invention belongs to the field of fluid mechanics and flow control, and in particular relates to an experimental device and method for realizing the hydrodynamic stealth of a bluff body through active flow control. Background Art

[0002] The flow field will change significantly after the fluid flows through the blunt body. For example, water flowing through a cylinder will produce a Karman vortex street. These asymmetric and unsteady changes are the hydrodynamic disturbances caused by the interaction between the blunt body and the flow field. Similarly, when the blunt body moves in still water, hydrodynamic disturbances will also be generated. Using hydrodynamic disturbance information for target detection is a new detection method discovered from the predator-prey relationship of aquatic biological communities. Based on the connection between the flow field information established by the organism and the upstream target, the shape and motion state of the object are judged by sensing the disturbance in the flow field. Active flow control can effectively change the flow field structure. It only needs to artificially apply small disturbances in the flow field to achieve the purpose of reducing drag and increasing lift, reducing vibration and noise, etc., and using deep reinforcement learning, more complex control goals can also be achieved.

[0003] Patent CN114323147A discloses a highly sensitive underwater bionic lateral line structure, which can detect hydrodynamic disturbances. As a new underwater sensor, it effectively supplements the deficiencies in the field of non-acoustic detection. In view of the new detection method using hydrodynamic disturbances for detection, it is urgent to develop a new hydrodynamic stealth method to achieve hydrodynamic stealth by eliminating the hydrodynamic disturbances generated by the movement of the blunt body in the fluid. Summary of the invention

[0004] Technical issues to be solved:

[0005] In order to avoid the shortcomings of the prior art, the present invention provides an experimental device and method for achieving hydrodynamic stealth of a bluff body through active flow control. When the bluff body model of the device moves in a fluid, the flow field will change significantly. The active flow control utilizes a generator to pump / suck fluid in the near-wall area to affect the development of the shear layer, thereby effectively changing the shape of the downstream wake vortex and achieving hydrodynamic stealth.

[0006] The technical solution of the present invention is: an experimental device for realizing the hydrodynamic stealth of a bluff body by active flow control, comprising a water tank, a single-degree-of-freedom vibration module, an active control module, a speed measurement module, and an intelligent body module, wherein the water tank provides a fluid environment for the experiment;

[0007] The single-degree-of-freedom vibration module includes a bluff body model, a bracket and a damper; the bluff body model is placed in water and slidably connected to a water tank through the bracket, so as to be able to perform simulated motion in the water; dampers are provided on both sides of the bluff body model to realize single-degree-of-freedom vibration of the bluff body in a vertical direction;

[0008] The active control module includes a generator and a water pump, wherein the generator is a jet hole arranged on the surface of the bluff body model, and the water pump is connected to the generator through a conduit;

[0009] The velocity measurement module is arranged at the rear of the bluff body model and is used to collect and feed back flow field information;

[0010] The intelligent body module receives the flow field information fed back by the speed measurement module, calculates the control parameters in real time, and controls the pumping and spraying actions and flow rate of the water pump in real time.

[0011] A further technical solution of the present invention is: the bracket includes an upper support rod, a side support rod and a lower support rod, the upper support rod is slidably connected to the outer edges of the opposite side walls of the water tank and can move linearly along the outer edges of the side walls of the water tank; the two ends of the blunt body model are fixedly connected to the lower support rod; the outer ends on both sides of the lower support rod are respectively connected to the two ends of the upper support rod through a damper and a side support rod.

[0012] A further technical solution of the present invention is: the damper comprises a columnar rod, an outer tube and a spring; the outer tube is a sleeve structure with an opening at the bottom and a central hole at the top; the columnar rod penetrates the outer tube along the axial direction, and a limiting device is provided in the middle; the spring is arranged in the outer tube, and its upper end is connected to the inner end surface of the top of the outer tube, and its lower end is connected to the upper end surface of the limiting device;

[0013] The bottom of the column rod is connected by a lower support rod, and the side wall of the outer cylinder is connected to the side support rod; based on the compression or pulling force of the spring, the column rod can make axial movement relative to the outer cylinder. Therefore, after the blunt body model is affected by external force and moves away from the equilibrium position of the spring, it will make single-degree-of-freedom vibration in the vertical direction under the restriction of the damper.

[0014] A further technical solution of the present invention is that the bluff body model is a hollow cylindrical structure, and a plurality of radial jet holes, namely generators, are arranged along the circumferential direction.

[0015] A further technical solution of the present invention is: the number of the generators is 10, and the central axes thereof form angles θ with the horizontal center line of the circular cross section of the blunt body model, θ=0°, ±40°, ±80°, ±120°, ±150°, 180°, respectively; the generator apertures on both sides of the horizontal center line are 1 / 30 of the circumference of the circular cross section of the blunt body model, and the generator apertures at other positions are 1 / 60 of the circumference of the circular cross section of the blunt body model.

[0016] A further technical solution of the present invention is: the jet actuation direction of the generator is horizontal, that is, water is pumped / sprayed only in the horizontal direction; the generators located at θ=±40°, ±80° receive the same control signals, and the generators at corresponding upstream and downstream positions, that is, the generators located at θ=+80° and θ=+120°, θ=+40° and θ=+150°, θ=0° and θ=180°, θ=-40° and θ=-150°, θ=-80° and θ=-120° receive control signals with a phase difference of 180°.

[0017] A further technical solution of the present invention is: the speed measurement module is connected to the bracket of the single-degree-of-freedom vibration module through a connecting frame, and is at a fixed distance from the blunt body model; it includes a pressure measuring tail rake, a data cable and an acquisition card, the sensors on the pressure measuring tail rake are arranged in an array form, and are connected to the acquisition card through a data cable to feed back the flow field information to the intelligent body module.

[0018] A further technical solution of the present invention is: the intelligent body module is a data processing terminal, including a high-performance computer and a single-chip microcomputer, which receives the flow field information obtained by the speed measurement module, calculates the control parameters in real time, and generates and sends an actuation signal to the active control module by the single-chip microcomputer.

[0019] A further technical solution of the present invention is: the water trough is a square trough with an opening at the top, and guide rails are arranged at the top ends of its two side walls. The bracket of the single-degree-of-freedom vibration module and the connecting frame of the speed measuring module are installed in cooperation with the guide rails, and the bracket is driven by a motor to move linearly along the guide rails, thereby driving the single-degree-of-freedom vibration module and the speed measuring module to move in the fluid.

[0020] A method for realizing hydrodynamic stealth of a bluff body by active flow control, the specific steps are as follows:

[0021] Step 1: After the motor is turned on, the bluff body model moves in the water tank and generates tail vortex shedding. At this time, the fluid generates a periodic force on the surface of the bluff body model; the fluid force stretches or compresses the damper, causing the bluff body model to vibrate in a single degree of freedom in the vertical direction;

[0022] Step 2: The pressure measuring tail rake of the velocity measuring module obtains the pressure in the downstream flow field and converts it to obtain the velocity in each direction at the fixed measuring point of the flow field;

[0023] Step 3: The intelligent agent module receives the flow field velocity information, and the computer performs online training, defines the speed difference between the wake velocity and the reference velocity as the objective function, and generates a control strategy through deep reinforcement learning; then the single-chip microcomputer outputs a control signal to the active control module, adjusts the water pump action according to the control signal, and then controls the speed of pumping / spraying water at the generator to modulate the flow field structure.

[0024] The generator is a jet hole arranged in an array on the periphery of the bluff body model. The bottom of the jet hole is connected to a duct, and a water pump is used to pump / spray into the flow field to affect the tail vortex structure. Through active flow control, the velocity loss of the fluid before and after the bluff body is reduced. Outside the near-field range of the bluff body, the bluff body cannot be perceived only by velocity and vortex information, thereby achieving the purpose of hydrodynamic stealth.

[0025] Beneficial Effects

[0026] The beneficial effects of the present invention are:

[0027] 1. When the bluff body model of the present invention moves in the fluid, the flow field will change significantly, and the active flow control utilizes the generator to pump / suck the fluid in the near-wall area to affect the development of the shear layer, thereby effectively changing the shape of the downstream wake vortex.

[0028] 2. The intelligent agent module of the present invention uses a deep reinforcement learning method to receive feedback information obtained from multiple flow field measurement points, and output multiple control signals to actuators at different positions through online calculation. By reasonably setting the action network and the evaluation network, the complex goal of reducing the fluid velocity loss before and after the blunt body passes can be achieved.

[0029] 3. The present invention utilizes deep reinforcement learning to generate control strategies and utilizes active flow control to modulate the flow field structure, which can effectively eliminate the fluid velocity loss before and after the blunt body passes through the fluid. In the near field, the hydrodynamic detection device cannot obtain the velocity and vortex change information, thereby ultimately achieving hydrodynamic stealth. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a general schematic diagram of an experimental device for realizing the hydrodynamic stealth of a bluff body by active control in the present invention;

[0031] Figure 2 It is a schematic diagram of a single degree of freedom vibration module in the present invention;

[0032] Figure 3 is a schematic diagram of the position of the active flow control generator in the present invention;

[0033] Figure 4 It is a schematic diagram of the position of the speed measurement module in the present invention;

[0034] Figure 5 is a schematic diagram of the interaction between the flow field and the intelligent agent module in the present invention;

[0035] Figure 6 It is a schematic diagram of the implementation effect of the present invention.

[0036] Explanation of the reference numerals: 1. water tank, 2. single degree of freedom vibration module, 3. speed measurement module, 4. active control module, 5. intelligent body module, 2-1. bracket, 2-2. columnar rod, 2-3. outer cylinder, 2-4. spring, 2-5. blunt body model. DETAILED DESCRIPTION

[0037] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0039] The present invention provides an experimental device for realizing the hydrodynamic stealth of a bluff body through active flow control, comprising the following components: a single-degree-of-freedom vibration module, an active control module, a speed measurement module, an intelligent body module and a water tank. The single-degree-of-freedom vibration module comprises a bluff body model, a bracket and a damper. The interior of the bluff body model is hollowed out to place a conduit. Both ends of the bluff body model are connected to the bracket, and the damper is installed on the bracket to realize the single-degree-of-freedom vibration of the bluff body in the vertical direction. The active control module comprises a generator, a water pump and a conduit. One end of the conduit is connected to the water pump, and the other end is connected to the generator on the surface of the bluff body, and the generator is a jet hole arranged on the surface of the bluff body. The actuation signal of the generator is generated and issued by the intelligent body module, and the water pump is controlled to realize the two actions of pumping and spraying water, and the flow rate is controlled in real time by the water pump. The speed measurement module comprises a pressure measuring tail rake, a data cable and an acquisition card. The sensors on the pressure measuring tail rake are arranged in an array form, and the specific positions are obtained by performing sensitivity analysis on the numerical simulation results before the experiment. The sensor on the pressure-measuring tail rake is connected to the acquisition card through a data cable to feed back the flow field information to the intelligent body module. The intelligent body module is a data processing terminal, which includes a high-performance computer and a single-chip microcomputer. It receives the flow field information obtained by the speed measurement module, calculates the control parameters in real time, and generates and sends the actuation signal to the active control module by the single-chip microcomputer. The water tank is a square tank with an opening on the top, and a guide rail is set at the top of the water tank to install the single-degree-of-freedom vibration module and the speed measurement module. The movement of the above two modules on the guide rail is controlled by a motor.

[0040] The single-degree-of-freedom vibration module is installed on the water tank rail. After the motor is turned on, the movement of the bluff body in the water tank will generate tail vortex shedding. At this time, the fluid generates a periodic force on the surface of the bluff body. Since the bluff body is connected to the damper through a bracket, the fluid force on the bluff body will stretch or compress the damper, which manifests as a single-degree-of-freedom vibration of the bluff body in the vertical direction.

[0041] The single-degree-of-freedom vibration module and the speed measuring module are arranged on the water tank guide rail at a fixed distance. The speed measuring module is installed behind the cylinder. The pressure measuring tail rake in the speed measuring module is used to obtain the pressure in the downstream flow field and convert it into the speed in each direction at the fixed measuring point of the flow field.

[0042] The flow field velocity information obtained in the velocity measurement module is transmitted to the intelligent agent module through the data line and the acquisition card. The high-performance computer in the intelligent agent module is used for online training, and the speed difference between the wake velocity and the reference velocity is defined as the objective function. The control strategy is generated through deep reinforcement learning, and the single-chip microcomputer is used to output the control signal to the active control module. The water pump is adjusted according to the control signal to control the speed of pumping / spraying water at the generator.

[0043] The generator of the active control module is a jet hole arranged in an array, the bottom of the jet hole is connected to the duct, and a water pump is used to pump / spray into the flow field to affect the tail vortex structure. The generator jet holes are arranged symmetrically along the axis of the blunt body. The phase of the control signal received by the generator in the upper and lower symmetrical position is consistent. In order to ensure the consistency of the inflow and outflow of the generator, the phase difference of the control signal received by the generator in the front and rear symmetrical position is 180°.

[0044] A velocity measurement module is set downstream of the single-degree-of-freedom vibration module to obtain velocity information in the flow field. According to the velocity information in the wake, a corresponding control strategy is formulated in the intelligent body module using deep reinforcement learning. Water is pumped / sprayed into the flow field through the generator in the active control module to modulate the flow field structure. Through active flow control, the velocity loss of the fluid before and after the bluff body is reduced. Outside the near-field range of the bluff body, the bluff body cannot be sensed by velocity and vortex information alone, thus achieving the purpose of hydrodynamic stealth.

[0045] Example:

[0046] This embodiment is a new detection method for target detection using hydrodynamic disturbances, and provides an experimental device for realizing the hydrodynamic stealth of a bluff body through active flow control. Figure 1 As shown, it includes the following components: a single degree of freedom vibration module 2, an active control module 4, a speed measurement module 3, an intelligent body module 5 and a water tank 1. In the near field, the bluff body cannot be sensed only by vortex and velocity information. The technical route is described in detail using a typical bluff body model of a cylinder as an example.

[0047] The single degree of freedom module 2 and the speed measurement module 3 are arranged front and back on the guide rail. Figure 1 The two modules are connected by a bracket to keep the relative distance consistent, and are driven by a motor placed outside the tank to move at a constant speed.

[0048] Single degree of freedom module 2 Figure 2 As shown in the figure, 2-1 is a bracket, 2-5 is a blunt body model, and the damper includes a columnar rod 2-2, an outer tube 2-3 and a spring 2-4. The outer tube 2-3 has an opening at the bottom, and the upper end surface is a spring mounting groove, which is connected to the upper part of the spring 2-4. At the same time, a hole is punched on the upper end surface, and the diameter of the hole is consistent with the diameter of the columnar rod 2-2, so as to ensure that the columnar rod 2-2 can be freely inserted in the outer tube 2-3. The middle part of the columnar rod 2-2 is a limit device on the columnar rod. The limit device is connected to the bottom of the spring 2-4. The columnar rod in the damper can only move in the direction of compression or pulling of the spring, and the bottom end of the columnar rod is connected to the bracket for installing the blunt body model 2-5. Therefore, after the blunt body is affected by an external force and moves away from the equilibrium position of the spring, it will vibrate with a single degree of freedom in the vertical direction under the restriction of the damper.

[0049] The generators in the active control module 4 are arranged on the cylindrical surface with reference to Figure 3 , a total of 10 generators. The generators are arranged at angles of θ=0°, ±40°, ±80°, ±120°, ±150°, and 180° to the center line. The opening size of the jet holes of the generators located at the center line, i.e., No. 3 and No. 8, is 1 / 30 of the circumference of the cylinder, and the opening size of the other openings is 1 / 60 of the circumference of the cylinder. The jet actuation direction is all horizontal, that is, water is pumped / sprayed only in the horizontal direction. The control signals received by the generators located at θ=±40°, ±80°, i.e., 1 and 5, 2 and 4, are the same, and the control signals received by the corresponding generators at the upstream and downstream positions, i.e., 1 and 6, 2 and 7, 3 and 8, 4 and 9, 5 and 10, are 180° apart in phase. The same control signal indicates that the generators pump / spray at the same time, and vice versa, when one of the generators pumps, the other sprays. The speed of pumping / spraying water of each generator is controlled by the corresponding water pump. Therefore, three control signals need to be output from the intelligent body module.

[0050] The arrangement of the sensor array in the pressure measuring tail rake is based on Figure 4 , a pressure measuring tail rake is set at the downstream position w1=2D of the cylinder, where the characteristic length D is the diameter of the cylinder. The distance between the pressure measuring tail rake and the cylinder remains unchanged during the movement. The pressure measuring tail rake is selected as a circular plane, which is perpendicular to the movement direction of the cylinder. The sensor arrangement is as follows: N=33 velocity sensors are selected and arranged on the surface. The specific position is obtained by evaluating the numerical simulation results through sensitivity analysis before the test. The radius of the pressure measuring tail rake is h1=2D. The final measurement point measures the velocity information u at a fixed position in the flow field downstream of the cylinder. i (i=1, 2, 3), that is, the pressure measuring tail rake can obtain N ui At the same time, the cylindrical motion speed is taken as the reference speed: refu i (i=1, 2, 3), the cylindrical motion speed can be directly measured by the motor. The speed loss is defined as:

[0051]

[0052] The ultimate goal of the present invention is to eliminate the fluid velocity loss J caused by cylindrical motion as much as possible.

[0053] In the agent module 5, the deep reinforcement learning method is used to perform calculations synchronously and output control parameters. The training of the deep reinforcement learning agent adopts the proximal strategy optimization model and interacts with the flow field. Figure 5 :Use the flow field state and actual reward measured by the sensor to generate actions to affect the flow field, where the actual reward is -J. Use neural networks to generate strategies, mainly including two sets of networks: action network and evaluation network. The evaluation network inputs flow field information and outputs predicted rewards. Its goal is to reduce the difference between predicted rewards and actual rewards. The action network inputs flow field information and outputs control parameters. Its goal is to increase reward gain.

[0054] The continuous control of the generator is applied by Gaussian disturbance, and the standard deviation is used as the speed change of the pumping / suction before and after. After the flow field information measured by the sensor is transmitted to the intelligent body module, it is calculated in real time and the standard deviation is output as the control parameter.

[0055] Before applying control, you first need to turn on the motor to drive the cylinder and the speed measurement module to move at a constant speed. Periodic vortex shedding will cause changes in the fluid dynamics on the surface of the cylinder, and the cylinder will vibrate. After a period of time, when the cylinder is in a stable vibration state, the active control module and the intelligent agent module are then turned on synchronously. Within a time interval of the generator actuation, the speed measurement module transmits the measured flow field measurement point information to the intelligent agent module. The intelligent agent module performs real-time online calculations through deep reinforcement learning methods, outputs control parameters to the active control module, and adjusts the water pump actuation so that the generator at the corresponding position pumps / sprays water at different speeds, affecting the tail vortex structure.

[0056] The standard deviation after multiple learnings keeps shrinking, the standard deviation of the Gaussian disturbance varies within a very small range around a constant value, the randomness and oscillation of applying continuous control have been eliminated, and the jet velocity remains unchanged.

[0057] The effect of hydrodynamic stealth achieved by active flow control The final effect reference Figure 6 .

[0058] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. An experimental device for achieving hydrodynamic stealth of a bluff body by active flow control, characterized in that: It includes a water tank, a single-degree-of-freedom vibration module, an active control module, a speed measurement module, and an intelligent body module. The water tank provides a fluid environment for the experiment. The water tank is a square tank with an opening on the top, and guide rails are arranged at the tops of the two side walls. The bracket of the single-degree-of-freedom vibration module and the connecting frame of the speed measurement module are both installed in cooperation with the guide rails. The bracket is driven by a motor to move linearly along the guide rails, thereby driving the single-degree-of-freedom vibration module and the speed measurement module to move in the fluid. The single-degree-of-freedom vibration module comprises a bluff body model, a bracket and a damper; the bluff body model is placed in water and slidably connected to the water tank through the bracket, so as to be able to perform simulated movement in the water; dampers are arranged on both sides of the bluff body model to realize the single-degree-of-freedom vibration of the bluff body in the vertical direction; the bracket comprises an upper support rod, a side support rod and a lower support rod, the upper support rod is slidably connected to the outer edges of the opposite side walls of the water tank, and can perform linear movement along the outer edges of the side walls of the water tank; the two ends of the bluff body model are fixedly connected to the lower support rod; the outer ends of the two sides of the lower support rod are respectively connected to the two ends of the upper support rod through the damper and the side support rod; the damper comprises The invention comprises a columnar rod, an outer cylinder and a spring; the outer cylinder is a sleeve structure with an opening at the bottom and a central hole at the top; the columnar rod penetrates the outer cylinder axially, and a limiting device is provided in the middle thereof; the spring is arranged in the outer cylinder, and its upper end is connected to the inner end surface of the top of the outer cylinder, and its lower end is connected to the upper end surface of the limiting device; the bottom of the columnar rod is connected through a lower support rod, and the side wall of the outer cylinder is connected to the side support rod; based on the compression or pulling force of the spring, the columnar rod can make axial movement relative to the outer cylinder, so after the blunt body model is affected by an external force and moves away from the equilibrium position of the spring, it will make a single degree of freedom vibration in the vertical direction under the restriction of the damper; The active control module includes a generator and a water pump, wherein the generator is a jet hole arranged on the surface of the bluff body model, and the water pump is connected to the generator through a conduit; The speed measurement module is arranged at the rear of the bluff body model, and is used to collect and feed back flow field information; the speed measurement module is connected to the bracket of the single-degree-of-freedom vibration module through a connecting frame; The intelligent body module receives the flow field information fed back by the speed measurement module, calculates the control parameters in real time, and controls the pumping and spraying actions and flow rate of the water pump in real time.

2. The experimental device for realizing hydrodynamic stealth of a bluff body by active flow control according to claim 1, characterized in that: The bluff body model is a hollow cylindrical structure, and is provided with a plurality of radial jet holes, namely, generators, along the circumference.

3. The experimental device for realizing hydrodynamic stealth of a bluff body by active flow control according to claim 2, characterized in that: The number of the generators is 10, and the central axes thereof are respectively at an angle with the horizontal central line of the circular cross section of the blunt body model. , The generator apertures on both sides of the horizontal center line are 1 / 30 of the circumference of the circular cross section of the blunt body model, and the generator apertures at other positions are 1 / 60 of the circumference of the circular cross section of the blunt body model.

4. The experimental device for realizing hydrodynamic stealth of a bluff body by active flow control according to claim 3, characterized in that: The jet actuation direction of the generator is horizontal, that is, water is pumped / sprayed only in the horizontal direction; , The control signal received by the generator is the same, and the upstream and downstream corresponding position generators, that is, located at , , , , The phase difference of the control signal received by the generator is 180°.

5. The experimental device for realizing hydrodynamic stealth of a bluff body by active flow control according to claim 1, characterized in that: The speed measurement module is at a fixed distance from the blunt body model; it includes a pressure measuring tail rake, a data line and an acquisition card. The sensors on the pressure measuring tail rake are arranged in an array and connected to the acquisition card through a data line to feed back the flow field information to the intelligent body module.

6. The experimental device for realizing hydrodynamic stealth of a bluff body by active flow control according to claim 1, characterized in that: The intelligent body module is a data processing terminal, including a high-performance computer and a single-chip microcomputer, which receives the flow field information obtained by the speed measurement module, calculates the control parameters in real time, and generates and sends an actuation signal to the active control module by the single-chip microcomputer.

7. A method for using the experimental device for realizing hydrodynamic stealth of a bluff body by active flow control as claimed in any one of claims 1 to 6, characterized in that The specific steps are as follows: Step 1: After the motor is turned on, the bluff body model moves in the water tank and generates tail vortex shedding. At this time, the fluid generates a periodic force on the surface of the bluff body model; the fluid force stretches or compresses the damper, causing the bluff body model to vibrate in a single degree of freedom in the vertical direction; Step 2: The pressure measuring tail rake of the velocity measuring module obtains the pressure in the downstream flow field and converts it to obtain the velocity in each direction at the fixed measuring point of the flow field; Step 3: The intelligent agent module receives flow field velocity information, the computer performs online training, defines the speed difference between the wake velocity and the reference velocity as the objective function, and generates a control strategy through deep reinforcement learning; Then the single chip microcomputer is used to output the control signal to the active control module, and the water pump action is adjusted according to the control signal, thereby controlling the speed of pumping / spraying water at the generator and modulating the flow field structure.

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