Active control wind tunnel for separately simulating average wind and fluctuating wind

Abstract

The invention discloses an active control wind tunnel for separately simulating average wind and fluctuating wind, and belongs to the technical field of wind tunnel experiment research. The wind tunnel is a single-experiment-section direct-current unsteady wind tunnel, and the front section of the wind tunnel is provided with a power section A; the power section A comprises an array fan located at the foremost end of the wind tunnel and used for generating pulsating wind and a fan A located in the flow direction of pulsating wind airflow and used for generating average wind, and airflow generated by the array fan and the fan A passes through the experiment section and is finally exhausted from an air outlet in the tail end of the wind tunnel; a rainfall device is arranged in the experiment section, and the wind tunnel is controlled by two independent active control modules, namely a fan A control system and an array fan control system; the array fan and the fan A can be used independently and can also be used in a combined mode to achieve simulation of complex wind field changes. A steady wind tunnel can be arranged on the lower layer of the unsteady wind tunnel, and the two layers of wind tunnels can be used independently or used in a combined mode to achieve natural phenomenon simulation and other specific functions.

Description

Technical Field

[0001] The invention relates to the technical field of wind tunnel experimental research, in particular to an active control wind tunnel for separately simulating average wind and pulsating wind. Background Art

[0002] A wind tunnel is an experimental device used to simulate airflow conditions in the atmosphere to study the movement and aerodynamic performance of objects in the air. A wind tunnel usually consists of an air duct, a fan, a measuring device, and a control system. It is widely used in aerodynamic research in the fields of architecture, aerospace, and automobiles. As an important aerodynamic experimental device, a wind tunnel plays an important role in engineering design and research.

[0003] Unsteady wind tunnels can simulate pulsating winds and provide information on the dynamic response and wind load of structures in complex wind field environments. By measuring the dynamic response of structures in these unsteady wind fields, the vibration characteristics and critical wind speed of the structure can be evaluated, thereby determining the stability and safety of the structure. Unsteady wind tunnel experiments can obtain the aerodynamic characteristics of the structure, including aerodynamic coefficients, lift and drag characteristics, etc. This information is crucial for optimizing the aerodynamic shape of the structure and improving the performance of the structure. Through experimental data, possible aerodynamic problems in the structure, such as aerodynamic instability and vibration, can be identified and resolved.

[0004] At present, array fans are widely used as the main driving equipment in unsteady wind tunnels. These fans not only need to generate uniform basic airflow, but also need to generate pulsating wind fields that meet the experimental requirements. However, in the existing technology, array fans have many limitations when taking into account these two functions. On the one hand, the fan array needs to achieve the generation of uniform flow through complex coordinated control, which places extremely high demands on the design, operation and maintenance of the wind tunnel; on the other hand, when generating pulsating wind, its response time is long, the dynamic adjustment ability is limited, and it is difficult to quickly achieve a high-frequency pulsating wind field. In addition, due to the limitations of the mechanical and electrical characteristics of the fan, the pulsating wind frequency that can be achieved in the current unsteady wind tunnel is relatively low, which is difficult to meet the needs of some high-frequency unsteady flow experiments. Therefore, it is an urgent need to develop an unsteady wind tunnel system with faster response speed and wider frequency coverage. Summary of the invention

[0005] In order to solve the limitations of traditional unsteady wind tunnels in terms of fast response and high-frequency simulation, the present invention provides an active control wind tunnel that simulates average wind and pulsating wind separately. Through an independent active control system, accurate generation of fast-response average wind and high-frequency pulsating wind is achieved, and wind field parameters can be flexibly adjusted according to experimental design requirements, providing a variety of complex wind load simulations.

[0006] The active control wind tunnel for simulating average wind and pulsating wind separately provided by the present invention is a single-experimental-section DC unsteady wind tunnel. A power section A is arranged at the front section of the wind tunnel. The power section A includes an array fan for generating pulsating wind located at the front end of the wind tunnel and a fan A for generating average wind located in the flow direction of the pulsating wind. A DC section is arranged between the array fan and the fan A. The airflow generated by the array fan and the fan A passes through the experimental section and is finally discharged from the air outlet at the end of the wind tunnel. A rainfall device is arranged in the experimental section and is located directly above the location where the building model is placed. A transparent window is also arranged on the experimental section for observing the experimental phenomena in the wind tunnel.

[0007] The unsteady wind tunnel is controlled by two independent active control modules, namely the fan A control system and the array fan control system; the fan A control system adopts a system structure of frequency converter + PLC + upper monitoring computer, forming a network topology based on PROFINET (Industrial Ethernet), realizing networked digital information transmission and process control, enhancing anti-interference ability, ensuring the motor (fan) speed control accuracy, and generating an average wind flow that meets the flow field index requirements. The array fan control system adopts a system structure of AC servo drive + AC servo motor + upper PXI (including control computer), which can output control strategies (instructions) to each servo drive according to the input control logic (mathematical model), thereby actively controlling the speed of each small fan in the array, realizing a more accurate simulation of complex wind field changes, and actively controlling the generation of pulsating wind that meets the special flow field characteristic indicators according to the formulated control logic (mathematical model).

[0008] The array fans and blower A can be used alone or in combination to simulate complex wind field changes.

[0009] A steady wind tunnel can also be set below the unsteady wind tunnel, and the steady wind tunnel is set close to the unsteady wind tunnel to form a double-layer wind tunnel structure. The steady wind tunnel is a sealed annular structure with an annular wind duct, and a power section B is set in the annular wind duct, and a fan B is set in the power section B. The average wind generated by the fan B passes through the first corner, the large diffusion section, and the second corner in turn to reach the first experimental section. The first experimental section passes through the third corner and the fourth corner to reach the second experimental section, and the second experimental section passes through the small diffusion section and returns to the power section B. The power drive of the fan B adopts an AC variable frequency speed regulation drive mode. The first experimental section and the second experimental section are used to realize the average wind simulation. The first experimental section is located directly below the unsteady wind tunnel, and an interactive window is set between the two to realize the vertical connection between the unsteady wind tunnel and the steady wind tunnel.

[0010] The interactive window is located near the air outlet, and an adjustable baffle is provided near the interactive window in the unsteady wind tunnel. The baffle can be selectively installed vertically or horizontally. When the baffle is installed vertically, it plays a guiding role and blocks the air outlet, so that the generated airflow passes downward through the interactive window into the steady wind tunnel, thereby realizing the simulation of a complex wind field; when the baffle is installed horizontally, the baffle covers the interactive window, thereby realizing the isolation between the steady wind tunnel and the unsteady wind tunnel, and a building model for the experiment is placed on the baffle.

[0011] Preferably, the array fan of the unsteady wind tunnel is composed of 7 rows and 16 columns, totaling 112 fans, and each fan is driven by an AC servo, and independently drives the servo motor to operate through the multi-channel synchronous output of analog voltage by the PXI system.

[0012] The two-layer wind tunnel composed of the unsteady wind tunnel and the steady wind tunnel of the present invention can be used alone or in combination to achieve specific functions such as simulating natural phenomena.

[0013] The unsteady wind tunnel has spatial non-uniformity, temporal non-uniformity, and a controllable spectrum, and can realize separate simulation of average wind and pulsating wind. The array fan and the fan A can be used alone or in combination to simulate complex wind field changes. The unsteady wind tunnel can generate a pulsating wind field and realize a high-frequency pulsating wind field, which is used to study the dynamic performance of building structures under single high-frequency wind-induced vibrations (such as sinusoidal waves, random pulsations, and segmented pulsating winds). The unsteady wind tunnel can also generate pulsating wind fields and average wind fields to simulate complex flow field characteristics and to study wind-rain coupling, local vortex effects, and wind-induced vibration responses.

[0014] When a steady wind tunnel is used in combination with an unsteady wind tunnel, the following simulations can be performed: (1) Downburst (2D): Passively simulate the tail rising section. The steady wind tunnel and the unsteady wind tunnel are connected vertically. The steady wind tunnel is equipped with a grid-type guide plate to make the airflow go upward. It is used to study the wind load caused by the airflow in the tail rising section of the downburst on the structure.

[0015] (2) Downburst (2D): Actively simulate the descending section of the airflow. The steady wind tunnel test section and the unsteady wind tunnel test section are connected vertically. A baffle is set in the unsteady wind tunnel test section to allow the airflow to flow downward into the steady wind tunnel test section. The steady wind tunnel fan B is not turned on, or the wind speed is low, which is used to study the wind field characteristics of the descending section of the downburst airflow.

[0016] (3) Tornado (2D): The steady wind tunnel test section and the unsteady wind tunnel test section are connected vertically. The unsteady wind tunnel is equipped with baffles to allow the airflow to enter the steady wind tunnel test section downward, simulating the tornado lift in reverse. The steady wind tunnel simulates the ground wind speed, and the unsteady wind tunnel generates rotating wind flow to simulate the characteristics of a tornado, which is used to study the wind field characteristics of tornado lift, etc.

[0017] Compared with the prior art, the present invention is beneficial in that: First, the unsteady wind tunnel of the present invention has high-frequency response capability and can generate high-precision pulsating wind fields with specific frequencies, amplitudes and modes (such as sine waves, random waves or segmented changes), which can be used to study phenomena such as high-frequency wind-induced vibrations, filling the gaps in conventional wind tunnels in high-frequency wind field simulations.

[0018] Secondly, the unsteady wind tunnel of the present invention can realize the superposition of average wind and pulsating wind, and simulate complex flow field characteristics, including wind-rain coupling, local eddy effect, irregular wind field, etc., and is widely used in the study of wind loads and aerodynamic performance in bridges, super-high buildings and aerospace fields.

[0019] Third, through the design of a test section that connects the unsteady wind tunnel and the steady wind tunnel, combined with the steady wind tunnel simulation and the airflow downward pressure function of the unsteady wind tunnel, accurate simulation of the two-dimensional tornado lift characteristics, downburst characteristics and wind load effects on the structure can be achieved, which is suitable for simulating natural disaster research and disaster prevention and mitigation design.

[0020] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the unsteady wind tunnel structure.

[0022] Figure 2 Schematic diagram of the control scheme of the control system of fan A and fan B.

[0023] Figure 3 Schematic diagram of the control scheme of the array fan control system.

[0024] Figure 4 Schematic diagram of the combination of steady wind tunnel and unsteady wind tunnel. Figure 5 Schematic diagram of the cross-sectional layout of the steady wind tunnel and the unsteady wind tunnel.

[0025] Figure 6 Schematic diagram of the simulation of irregular pulsating wind in an unsteady wind tunnel.

[0026] Figure 7 Schematic diagram of unsteady wind tunnel wind-rain coupling simulation.

[0027] Figure 8 Schematic diagram of the passive simulation of the tail rise section of a downburst.

[0028] Fig. 9 Schematic diagram of the active simulation of the descending airflow section of the downburst and the reverse simulation of the tornado lift.

[0029] Numbers in the figure: 1-power section A, 2-array fan, 3-DC section, 4-fan A, 5-experimental section, 6-air outlet, 7-rainfall device, 8-transparent window, 9-power section B, 10-first corner, 11-large diffusion section, 12-second corner, 13-large contraction section, 14-first experimental section, 15-third corner, 16-fourth corner, second experimental section 17, 18-small diffusion section, 19-first turntable, 20-building model, 21-second turntable, 22-unsteady wind tunnel, 23-interactive window, 24-baffle, 25-bracket, 26-guide plate. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0031] like Figure 1-Figure 9 As shown, the active control wind tunnel for simulating average wind and pulsating wind separately provided by the present invention is a single-experimental-section DC unsteady wind tunnel 22. A power section A1 is set at the front section of the wind tunnel 22. The power section A1 includes an array fan 2 located at the front end of the wind tunnel for generating pulsating wind and a fan A4 located in the flow direction of the pulsating wind for generating average wind. A DC section 3 is set between the array fan 2 and the fan A4. The airflow generated by the array fan 1 and the fan A4 passes through the experimental section 5 and is finally discharged from the air outlet 6 at the end of the wind tunnel. A rainfall device 7 is set in the experimental section 5, and the rainfall device 7 is located directly above the location where the building model is placed. The structure of the rainfall device 7 is not limited, as long as it can play the function of dropping water downward at the top of the unsteady wind tunnel. At least one transparent window 8 is also set on the experimental section 5, which is made of transparent material and can be used to observe the experimental phenomena in the wind tunnel from the outside. The required pulsating airflow is generated by adjusting the wind speed and wind direction of each fan in the array fan 2. The pulsating wind generated by the array fan 2 enters the average wind area generated by the fan A4 through the straight line segment 3. The array fan actively controls the superimposed pulsating characteristics to form a superposition of the pulsating wind and the average wind, and finally flows out from the air outlet 6.

[0032] The unsteady wind tunnel 22 is controlled by two independent active control modules, namely, the fan A1 control system and the array fan 2 control system. By separately controlling the array fan 2 and the fan A4, the pulsating wind and the average wind are controlled and simulated separately. The fan and the array fan can be used alone or in combination to achieve a fast response high-frequency simulation of a complex wind field, which is particularly suitable for studying the dynamic response of pulsating wind to building structures, bridges and other engineering facilities.

[0033] The required pulsating airflow is generated by adjusting the wind speed and wind direction of each fan in the array fan 2. The speed and wind direction of each fan in the array can be actively controlled according to the input control logic to achieve a more accurate simulation of complex wind field changes, with a maximum wind speed of 20m / s and a pulsation frequency of up to 5Hz. In a specific embodiment, the array fan 2 is composed of 7 rows and 16 columns, totaling 112 fans, each fan adopts an AC servo drive mode, and independently drives the servo motor to operate through the multi-channel synchronous output of analog voltage by the PXI system.

[0034] The specific control scheme of fan A1 control system is as follows Figure 2 As shown in the figure, the power drive of fan A1 adopts AC variable frequency speed regulation drive mode. According to the input target constant flow information, the upper management computer sends instructions to the DC wind tunnel control system through Ethernet, and the latter coordinates the operation of each execution unit through PLC. According to the received instructions, the PLC controls the speed of the 90KW variable frequency motor through the inverter, drives the transmission system and fan system to generate airflow, and controls the start of the cooling fan to ensure the heat dissipation of the system. The sensor system monitors the wind tunnel cavity temperature, transmission bearing temperature and vibration, and airflow speed and pressure in real time, and feeds back to the PLC to achieve closed-loop control, ensuring that the wind tunnel operates under stable and safe conditions, providing a controllable flow field environment for the test.

[0035] The specific control scheme of the array fan 2 control system is as follows: Figure 3 As shown in the figure, by actively controlling the operation of multiple small servo motors, the array fans are driven to generate unsteady airflows with complex characteristics. The digital intelligent controller used in the active control of multiple fans includes a model predictive control strategy + a target wind field feedback digital algorithm. First, the wind field model is predicted by the digital intelligent controller according to the target wind field input by the computer, and is transmitted to the PXI system through digital instructions. The PXI controller executes the digital instructions and synchronously outputs various analog instructions for controlling the active fans to the servo driver. The servo motor responds to the driver in real time to provide power sources for each active fan. The feedback digital algorithm uses the speed and pressure sensors and temperature sensors distributed at several measurement points in the test section to feed back the wind field data and the target wind field data in real time for intelligent calculation to form digital instructions. The PXI controller executes the digital instructions to quickly form an unsteady flow wind field in the wind tunnel.

[0036] like Figure 4 and 5As shown, a steady wind tunnel can also be arranged below the unsteady wind tunnel 22, and the steady wind tunnel is arranged close to the unsteady wind tunnel 22 to form a double-layer wind tunnel structure. The steady wind tunnel is a sealed annular structure with an annular wind duct, and a power section B9 is arranged in the annular wind duct, and a fan B is arranged in the power section B9. The average wind generated by the fan B passes through the first corner 10, the large diffusion section 11, the second corner 12, and the large contraction section 13 in sequence to reach the first experimental section 14, and the first experimental section 14 passes through the third corner 15 and the fourth corner 16 to reach the second experimental section 17, and the second experimental section 17 passes through the small diffusion section 18 and returns to the power section B9. A first turntable 19 is arranged in the first experimental section 14, and a building model 20 for the experiment is placed on the first turntable 19. A second turntable 21 is arranged in the second experimental section 17. The first experimental section 14 is a high wind speed experimental section with a maximum wind speed of 51m / s. The maximum wind speed of the second experimental section 17 is 18m / s. The first experimental section 14 and the second experimental section 17 are used to achieve average wind simulation. The first experimental section 14 is located directly below the unsteady wind tunnel 22, and an interactive window 23 is provided between the two to achieve vertical connection between the unsteady wind tunnel and the steady wind tunnel. The power drive of the fan B adopts an AC variable frequency speed regulation drive mode.

[0037] The interactive window 23 is located near the air outlet 6. An adjustable baffle 24 is provided near the interactive window in the unsteady wind tunnel. The baffle can be selectively installed vertically or horizontally. When the baffle is installed vertically, it plays a guiding role and blocks the air outlet 6, so that the generated airflow passes downward through the interactive window 23 into the steady wind tunnel, realizing the simulation of a complex wind field. When the baffle 24 is installed horizontally, the baffle covers the interactive window 23, realizing the isolation of the steady wind tunnel and the unsteady wind tunnel, and the building model 20 for the experiment is placed on the baffle 24. Furthermore, a bracket 25 for installing and fixing the double-layer wind tunnel structure can be provided below the steady wind tunnel.

[0038] In one embodiment, a guide plate 26 is provided in the steady wind tunnel. The guide plate 26 is located below the interactive window 23. The guide plate 26 allows the airflow in the steady wind tunnel to flow upward to simulate the ascending section of the downburst.

[0039] The control system used by the fan B is the same as that of the fan A.

[0040] The two-layer wind tunnel composed of the steady wind tunnel and the unsteady wind tunnel of the present invention can be used alone or in combination to achieve specific functions such as simulating natural phenomena. Examples are as follows: like Figure 6As shown: the baffle 24 covers the interactive window 23, and the unsteady wind tunnel is used alone to simulate high-frequency pulsating wind. This mode is designed to study the dynamic impact of high-frequency pulsating wind (such as sine wave, random pulsation, and segmented pulsating wind) on buildings. The unsteady wind tunnel only turns on the array fan, and through a precise control system, pulsating winds of different frequencies and amplitudes are configured to achieve pulsating wind simulation with a frequency range of 0.1 Hz to 5 Hz, covering the main frequency distribution of a typical pulsating wind field. The fan speed is controlled by a servo drive to simulate the changes in the high-frequency pulsating wind field.

[0041] like Figure 7 As shown: the baffle 24 covers the interactive window 23, the unsteady wind tunnel is used alone, and the pulsating wind field + average wind field are used in combination; this combination is used to study the coupling effect of wind and rain, local vortex effect and wind-induced vibration response. In the unsteady wind tunnel, fan A provides a stable background wind speed and wind direction. By adjusting the speed of fan A, the target wind speed can be accurately controlled; while the array fan simulates the wind field changes in the real environment through pulsating wind, and quickly generates a pulsating wind field with high frequency, amplitude and waveform. Thus, a complex flow field with pulsating wind and average wind superimposed on each other is simulated. The rainfall device is used to simulate rainfall load.

[0042] like Figure 8 As shown, the baffle 24 is installed vertically to achieve vertical connection between the steady wind tunnel and the unsteady wind tunnel; the steady wind tunnel and the unsteady wind tunnel are combined to simulate the downburst (two-dimensional), passively simulate the tail rising section, and mainly study the rising characteristics of the airflow. Steady wind tunnel section: a grid-type guide plate 26 is set in the first experimental section to ensure that the airflow flows upward. Unsteady wind tunnel section: the pulsating characteristics of the rising airflow are generated by the control system to simulate the dynamic behavior of the storm. Sensors can also be set to monitor the airflow speed and direction, and real-time feedback is fed back to the control system to adjust the wind speed and direction of the unsteady wind tunnel.

[0043] like Fig. 9 As shown, the baffle 24 is installed vertically to realize the vertical connection between the steady wind tunnel and the unsteady wind tunnel; the steady wind tunnel and the unsteady wind tunnel are combined to actively simulate the descending section of the airflow or reversely simulate the lift of the tornado, and study the impact of the airflow descent or tornado on the building. Steady wind tunnel section: The first experimental section is vertically connected with the unsteady wind tunnel, and the fan B of the steady wind tunnel is turned off or set to a low wind speed to reduce the interference of the background wind on the experiment, and cooperates with the rainfall device 7 to simulate the wind and rain load. The steady wind tunnel part of the tornado mode simulates the ground wind speed, and the unsteady wind tunnel part generates a rotating wind flow through the control system to simulate the characteristics of a tornado. By adjusting the speed and direction of the fan, an airflow that conforms to the characteristics of a tornado is created.

[0044] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An active control wind tunnel for simulating mean wind and fluctuating wind separately, characterized in that: The wind tunnel is a single-experimental-section DC unsteady wind tunnel. A power section A is set at the front section of the wind tunnel. The power section A includes an array fan located at the front end of the wind tunnel for generating pulsating wind and a fan A located in the flow direction of the pulsating wind for generating average wind. A DC section is set between the array fan and the fan A. The airflow generated by the array fan and the fan A passes through the experimental section and is finally discharged from the air outlet at the end of the wind tunnel. A rainfall device is provided in the experimental section, and the rainfall device is located directly above the location where the building model is placed; The wind tunnel is controlled by two independent active control modules, namely, the fan A control system and the array fan control system; the fan A control system adopts a system structure of frequency converter + PLC + upper monitoring computer, forming a network topology based on industrial Ethernet, realizing networked digital information transmission and process control; the array fan control system adopts a system structure of AC servo driver + AC servo motor + upper PXI, and outputs control strategies to each servo driver according to the input control logic, so as to actively control the wind speed and wind direction of each fan in the array and generate the required pulsating airflow; The array fans and blower A can be used alone or in combination to simulate complex wind field changes.

2. The active control wind tunnel for separately simulating average wind and pulsating wind as claimed in claim 1, characterized in that: It also includes a steady wind tunnel arranged below the unsteady wind tunnel, the steady wind tunnel is arranged close to the unsteady wind tunnel to form a double-layer wind tunnel structure, an interactive window is arranged between the steady wind tunnel and the unsteady wind tunnel to achieve vertical connection between the unsteady wind tunnel and the steady wind tunnel; the interactive window is located close to the air outlet, and an adjustable baffle is arranged near the interactive window in the unsteady wind tunnel, and the baffle can be selectively installed vertically or horizontally. When the baffle is installed vertically, it plays a guiding role and blocks the air outlet, so that the generated airflow passes downward through the interactive window into the steady wind tunnel, thereby realizing the simulation of a complex wind field; when the baffle is installed horizontally, the baffle covers the interactive window to achieve isolation between the steady wind tunnel and the unsteady wind tunnel, and a building model for the experiment is placed on the baffle.

3. The active control wind tunnel for separately simulating average wind and fluctuating wind as claimed in claim 2, characterized in that: The steady wind tunnel is a sealed annular structure with an annular wind duct. A power section B is arranged in the annular wind duct. A fan B is arranged in the power section B. The average wind generated by the fan B passes through the first corner, the large diffusion section, and the second corner in sequence to reach the first experimental section. The first experimental section passes through the third corner and the fourth corner to reach the second experimental section. The second experimental section passes through the small diffusion section and returns to the power section B. The first experimental section is located directly below the unsteady wind tunnel.

4. The active control wind tunnel for separately simulating average wind and fluctuating wind as claimed in claim 2, characterized in that: The control system of the fan B is the same as the control system of the fan A.

5. The active control wind tunnel for separately simulating average wind and fluctuating wind as claimed in claim 1, characterized in that: The unsteady wind tunnel is also provided with a transparent window for observing experimental phenomena in the wind tunnel.

6. The active control wind tunnel for separately simulating average wind and fluctuating wind as claimed in claim 1, characterized in that: The power drive of the fan B of the steady wind tunnel adopts an AC variable frequency speed regulation drive mode.

7. The active control wind tunnel for separately simulating mean wind and pulsating wind as claimed in claim 1, characterized in that: The array fan of the unsteady wind tunnel consists of 7 rows and 16 columns, totaling 112 fans. Each fan adopts an AC servo drive mode and independently drives the servo motor to operate through the multi-channel synchronous output of analog voltage by the PXI system.

8. The active control wind tunnel for separately simulating average wind and fluctuating wind as claimed in claim 2, characterized in that: When the baffle covers the interactive window, the array fan in the unsteady wind tunnel is used alone to simulate pulsating wind, and the array fan and fan A are used in combination and cooperate with the rainfall device to simulate wind-rain coupling.

9. The active control wind tunnel for separately simulating mean wind and fluctuating wind as claimed in claim 2, characterized in that: When simulating the ascending section of a downburst, a baffle is installed vertically in the unsteady wind tunnel to block the air outlet, and a guide plate is set in the steady wind tunnel. The guide plate is located below the interactive window, and the airflow in the steady wind tunnel flows upward through the guide plate. The unsteady wind tunnel generates the pulsating characteristics of the ascending airflow to simulate the dynamic behavior of the downburst.

10. The active control wind tunnel for separately simulating mean wind and pulsating wind as claimed in claim 2, characterized in that: When simulating the descending section of a downburst, the baffle in the unsteady wind tunnel is installed vertically to play a guiding role, and the fan B in the steady wind tunnel is turned off or set to a low wind speed, and the rain device is used to simulate wind and rain loads. When simulating a tornado, the steady wind tunnel simulates the ground wind speed, and the unsteady wind tunnel generates a rotating wind flow to simulate the characteristics of a tornado.

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