Multifunctional Wind Tunnel System with Switchable and Simultaneous Open / Closed Circuit Operation and Method Thereof

Abstract

The first objective of the present invention is to overcome operational limitations caused by existing wind tunnel devices providing only one of an open circuit or a closed circuit, and to provide a multifunctional wind tunnel device capable of switching between open / closed circuits and operating in parallel, which allows for the free switching or simultaneous operation of the two methods within a single wind tunnel device, and a method of operating the same. To achieve the above objective, a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to one embodiment of the present invention comprises: a test section; a blower that flows air passing through the test section; a contraction section and a diffusion section disposed between the blower and the test section; and a plurality of corner ducts that connect the contraction section and the diffusion section to allow air to circulate inside the device; wherein at least one of the corner ducts is formed to be detachably attachable.

Description

Technology Field

[0001] The present invention relates to a multifunctional wind tunnel device capable of switching between open and closed circuits and parallel operation, and a method of operating the same. In particular, unlike conventional wind tunnels that provide only one of an open circuit or a closed circuit method, the invention relates to a multifunctional wind tunnel device capable of switching between open and closed circuits and a method of operating the same, configured to selectively switch between open and closed circuit operation methods or operate them simultaneously within a single wind tunnel device. Background Technology

[0003] A wind tunnel is a key device for testing the aerodynamic characteristics of various structures or equipment, such as aircraft, vehicles, and weapon systems, enabling experiments by artificially reproducing a constant flow environment.

[0004] These wind tunnels are generally classified into two types: open circuit and closed circuit.

[0005] An open wind tunnel has a structure that draws in external air, passes it through a test section, and immediately discharges it to the outside; it has the advantages of a simple device structure, low installation costs, and easy maintenance.

[0006] In addition, since internal air can be quickly vented after testing, it is suitable for simulating atmospheric conditions or for tests where ventilation is required.

[0007] However, there is a limitation in that if chemicals or pollutants are injected into the wind tunnel during testing, they may be released directly to the outside, potentially causing environmental pollution or safety issues.

[0008] In contrast, circulating wind tunnels have a structure in which air passing through the test section is not discharged to the outside but is recirculated within the device, offering high air flow stability and energy efficiency.

[0009] This method is suitable for precise aerodynamic testing as it can maintain a constant flow environment for an extended period, and it has the particular advantage of maintaining a constant internal concentration by blocking external diffusion.

[0010] However, there is a disadvantage in that air exchange with the outside is limited, making the discharge and purification of chemicals or pollutants complex and time-consuming, and making it difficult to rapidly change test conditions.

[0011] As existing wind tunnel technology relies solely on a single operational method as described above, if a different type of wind tunnel is required for a test purpose, a separate wind tunnel facility must be constructed, which consumes enormous space and costs.

[0012] In particular, existing wind tunnel structures are not sufficient when various environmental conditions must be simulated, such as in the testing and evaluation of CBRN (Chemical, Biological, Radiological, Nuclear) protection equipment, or when rapid evacuation after testing is required.

[0013] Therefore, a wind tunnel structure is required that allows for the free switching between open and circular operation modes or simultaneous parallel operation depending on the test purpose.

[0014] This structure complements the shortcomings of existing wind tunnels and can significantly improve test efficiency and safety by providing a multi-functional test environment with a single device. Prior art literature

[0016] Korean Patent Publication No. 10-2025-0046819 The problem to be solved

[0017] The first objective of the present invention, which is to solve the conventional problems described above, is to overcome the operational limitations caused by existing wind tunnel devices providing only one of an open circuit or a closed circuit, and to provide a multi-functional wind tunnel device capable of switching between open / closed circuits and operating in parallel, which allows for the free switching or simultaneous operation of the two methods within a single wind tunnel device, and a method of operating the same.

[0018] In addition, the second objective of the present invention is to provide a multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation, which can simply and quickly switch wind tunnel circuits according to the test purpose, thereby enabling various operating modes that were previously only possible by building a separate wind tunnel device, and a method of operating the same.

[0019] In addition, the third objective of the present invention is to provide a multifunctional wind tunnel device capable of switching between Open / Closed circuits and operating in parallel, which can minimize diffusion to the outside by utilizing a circulating circuit to ensure safety in tests in which chemical substances or contaminants are injected, and can rapidly discharge by switching to an open circuit when necessary, thereby reducing the risk to the tester and the surrounding environment, and a method of operating the same.

[0020] In addition, the fourth objective of the present invention is to provide a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, which enables multi-purpose operation with a single device to improve test efficiency and economy, reduces the cost and space required to build and operate a separate wind tunnel device, and significantly reduces the burden of test preparation and switching for research personnel, and a method of operating the same.

[0021] In addition, the fifth objective of the present invention is to provide a multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation, which can implement a customized environment tailored to a specific test purpose by providing a parallel mode that expands the flexibility of the test environment and simultaneously operates some sections as a circular type and some sections as an open type, and particularly in the field of chemical, biological, radiological, and nuclear (CBRN) test evaluation, which can simultaneously satisfy the simulation of various environmental conditions and rapid discharge after testing, and a method of operating the same.

[0022] In addition, the sixth objective of the present invention is to provide a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, and a method of operating the same, which can overcome the limitations of a single operation method of existing wind tunnels and realize a new concept wind tunnel device capable of simultaneously securing safety, economy, flexibility, and test efficiency. means of solving the problem

[0024] To achieve the above objective, a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to one embodiment of the present invention comprises: a test section; a blower that flows air passing through the test section; a contraction section and a diffusion section disposed between the blower and the test section; and a plurality of corner ducts that connect the contraction section and the diffusion section to allow air to circulate inside the device; wherein at least one of the corner ducts is formed to be detachably attachable.

[0025] In addition, the multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention is characterized in that, when the corner duct is connected, it operates in a circulating mode in which air circulates within the device, and when the corner duct is removed or opened, it operates in an open mode connected to the outside.

[0026] In addition, the multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention is characterized by operating in a parallel mode in which a circulating mode and an open mode are operated in parallel when only a part of the corner duct is connected.

[0027] In addition, in a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention, the corner duct is characterized by including a rail structure or a bolt fastening structure.

[0028] In addition, the multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention includes a sensor that detects whether the corner duct is attached or detached, and is characterized in that the operating mode of the wind tunnel is automatically controlled according to the signal of the sensor.

[0029] In addition, the multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention is characterized by including a plurality of sensors for detecting internal pressure, temperature, humidity, flow rate, and chemical concentration, and further including a control unit for controlling the operation mode based on the measured values ​​of the sensors.

[0030] In addition, the multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention is characterized by further including a supply unit for supplying a chemical substance or aerosol into the test section.

[0031] In addition, in a multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention, the supply unit is characterized by being configured to selectively supply a chemical substance in the form of a liquid, gas, or powder.

[0032] In addition, the multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention is characterized by further including an exhaust unit for discharging internal air to the outside after the test is completed.

[0033] In addition, in a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention, the discharge section is characterized by being configured to include a filter or an adsorbent to minimize diffusion into the environment when internal chemicals are discharged to the outside.

[0034] In addition, to achieve the above objective, a method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to another embodiment of the present invention is characterized by comprising: a first step in which air passing through a test section is flowed by a blower; a second step in which an air flow is formed by a contraction section and a diffusion section disposed between the blower and the test section; and a third step in which at least one of a plurality of corner ducts connecting the contraction section and the diffusion section is formed to be detachably attached.

[0035] In addition, in the method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention, the device is characterized by being operated in a circulating mode when all corner ducts are connected, and in an open mode when the corner ducts are removed or opened.

[0036] In addition, in the method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention, when the corner duct is only partially connected, the device is operated in a parallel mode in which a circulating mode and an open mode are operated in parallel.

[0037] In addition, in the method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention, the corner duct is characterized by including a rail structure or a bolt fastening structure.

[0038] In addition, the method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention is characterized by including a sensor that detects whether the corner duct is attached or detached, and the operating mode of the wind tunnel is automatically controlled according to the signal of the sensor.

[0039] In addition, the method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention is characterized by further including a control unit that controls an operating mode based on the measured values ​​of the sensors, and includes a plurality of sensors that detect internal pressure, temperature, humidity, flow rate, and chemical concentration.

[0040] In addition, the method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention is characterized by further including a supply unit for supplying a chemical substance or aerosol into the test section.

[0041] In addition, in the method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention, the supply unit is characterized by being configured to selectively inject a chemical substance in the form of a liquid, gas, or powder.

[0042] In addition, the method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention is characterized by further including an exhaust unit for discharging internal air to the outside after the test is completed.

[0043] In addition, in the method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention, the discharge unit is characterized by being configured to include a filter or an adsorbent to minimize diffusion into the environment when internal chemical substances are discharged to the outside.

[0044] In addition, the multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to the present invention is characterized by operating by the method of operating the multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation.

[0046] Specific details of other embodiments are included in "Specific details for implementing the invention" and the attached "drawings".

[0047] The advantages and / or features of the present invention and the methods for achieving them will become clear by referring to the various embodiments described below in detail together with the accompanying drawings.

[0048] However, it should be understood that the present invention is not limited to the configurations of each embodiment disclosed below, but may be implemented in various different forms, and that each embodiment disclosed in this specification is provided merely to make the disclosure of the present invention complete and to fully inform those skilled in the art of the scope of the present invention, and that the present invention is defined only by the scope of each claim of the claims. Effects of the invention

[0050] As such, the present invention has the effect of overcoming the structural and operational limitations of existing wind tunnels and providing a multi-purpose test environment capable of responding to various test purposes.

[0051] In addition, according to the present invention, since closed circuit, open circuit, and hybrid operation modes can be selectively implemented in a single device, the necessary operation method can be immediately switched according to the test purpose, thereby providing significantly higher flexibility compared to existing wind tunnels with a single operation method and having the effect of enabling various test scenarios to be performed in a single device.

[0052] In addition, according to the present invention, since wind tunnel circuit switching is rapidly performed through a simple detachable corner duct structure, the test environment can be changed quickly, thereby shortening test preparation time and enabling efficient execution of continuous tests under various conditions, while reducing the burden on research personnel and improving overall test productivity.

[0053] In addition, according to the present invention, when operating a circulating circuit, air exchange with the outside is blocked, thereby minimizing the risk of chemicals or contaminants injected into the wind tunnel spreading to the outside. Furthermore, since the internal air can be immediately switched to an open circuit to be discharged to the outside when necessary, rapid discharge and purification are possible after the test is completed, which has the effect of significantly improving safety for researchers, test equipment, and the external environment.

[0054] In addition, according to the present invention, since multi-purpose operation is provided with a single wind tunnel device, the spatial and economic burden of having to construct an open wind tunnel and a circulating wind tunnel separately as in the past can be drastically reduced, thereby reducing installation costs, maintenance costs, and operating costs, and enabling the efficient utilization of resources by research institutions or test and evaluation institutions.

[0055] Furthermore, according to the present invention, it can be optimized and utilized not only in traditional aerodynamic testing fields such as aircraft or vehicles, but also in chemical, biological, radiological, and nuclear (CBRN) protection equipment testing and evaluation, environmental simulation testing, and special-purpose airflow control experiments. Since it can provide a customized flow environment tailored to specific test purposes through a parallel operation mode, it has the effect of enabling complex environmental testing that was difficult to perform in conventional wind tunnels.

[0056] Furthermore, according to the present invention, by simultaneously achieving effects such as multi-functional operation tailored to the test purpose, improved test efficiency, enhanced safety, economic feasibility, and expanded usability, it is possible to provide a new paradigm for providing test environments in the field of wind tunnel technology. Brief explanation of the drawing

[0058] FIG. 1 is a perspective view showing the basic structure of a multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to one embodiment of the present invention. FIG. 2 is a plan view showing the basic structure of a multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to an embodiment of the present invention. FIG. 3 is a side view showing the basic structure of a multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to an embodiment of the present invention. FIG. 4 is a schematic diagram showing the airflow in a circulating mode in a multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to one embodiment of the present invention. FIG. 5 is a schematic diagram showing airflow in open mode in a multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to an embodiment of the present invention. FIG. 6 is a drawing showing a detachable corner duct in a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to an embodiment of the present invention. FIG. 7 is a flowchart showing the overall flow of an operation method of a multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to another embodiment of the present invention. Specific details for implementing the invention

[0059] Before describing the present invention in detail, it should be understood that the terms and words used in this specification should not be interpreted as being limited to their ordinary or dictionary meanings, and that the inventor of the present invention may appropriately define and use the concepts of various terms to best describe their invention, and furthermore, that these terms and words should be interpreted in a meaning and concept consistent with the technical spirit of the present invention.

[0060] In other words, it should be understood that the terms used in this specification are used merely to describe preferred embodiments of the present invention and are not intended to specifically limit the content of the present invention, and that these terms are defined in consideration of various possibilities of the present invention.

[0061] In addition, it should be noted that in this specification, singular expressions may include plural expressions unless the context clearly indicates a different meaning, and that even if they are expressed in a similarly plural form, they may include a singular meaning.

[0062] Throughout this specification, where it is stated that a component "includes" another component, unless specifically stated otherwise, this may mean that it does not exclude any other component but may include any other component.

[0063] Furthermore, it should be noted that in cases where it is stated that a component "exists inside or is installed in connection with" another component, this component may be installed in direct connection or contact with the other component, or it may be installed at a certain distance apart, and in the case where it is installed at a certain distance apart, there may be a third component or means for fixing or connecting the component to the other component, and a description of this third component or means may be omitted.

[0064] On the other hand, if it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there is no third component or means.

[0065] Likewise, other expressions describing the relationship between each component, such as “between” and “right between”, or “adjacent to” and “directly adjacent to”, should be interpreted as having the same intent.

[0066] In addition, it should be understood that in this specification, terms such as “one side,” “other side,” “one side,” “other side,” “first,” “second,” etc., are used to clearly distinguish one component from another component, and that the meaning of the component is not restricted by such terms.

[0067] In addition, position-related terms such as "up," "down," "left," and "right" used in this specification should be understood as indicating the relative position of the corresponding component in the drawing, and unless an absolute position is specified, these position-related terms should not be understood as referring to an absolute position.

[0068] Furthermore, in specifying the reference numerals for each component of each drawing in this specification, the same component has the same reference numeral even if it is shown in different drawings; that is, the same reference numeral throughout the specification indicates the same component.

[0069] In the drawings attached to this specification, the size, position, connection relationships, etc., of each component constituting the present invention may be described in a partially exaggerated, reduced, or omitted manner for the convenience of explanation or to sufficiently clearly convey the concept of the present invention, and therefore, the proportions or scale may not be strictly accurate.

[0070] In addition, in describing the present invention below, detailed descriptions of components, such as prior art and known technology, that are deemed to unnecessarily obscure the essence of the invention may be omitted.

[0072] Hereinafter, embodiments of the present invention will be described in detail with reference to the relevant drawings.

[0074] FIG. 1 is a perspective view showing the basic structure of a multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to an embodiment of the present invention, FIG. 2 is a plan view showing the basic structure of a multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to an embodiment of the present invention, and FIG. 3 is a side view showing the basic structure of a multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to an embodiment of the present invention.

[0075] Referring to FIGS. 1 to 3, a multi-functional wind tunnel device (1000) capable of Open / Closed circuit switching and parallel operation according to one embodiment of the present invention includes a test section (100), a contraction section (200), a diffusion section (300), a corner duct (400), a blower (500), a supply section (600), a discharge section (700), and a rectification section (800).

[0076] This configuration controls the airflow and allows the wind tunnel to be operated in a closed circuit, open circuit, or a parallel mode combining both, depending on the test purpose.

[0078] The test section (100) is formed in the central part of the wind tunnel and is a space where a test object is placed and its performance or characteristics are evaluated by actual air flow.

[0079] The test section (100) is a core section of the device, into which a chemical substance or aerosol injected through the supply section (600) is introduced and mixed with the airflow and acts on the test subject.

[0080] In the test section (100), pressure sensors, flow rate sensors, chemical concentration sensors, etc. are installed as needed to monitor test conditions in real time.

[0081] To explain in more detail, as shown in FIGS. 1 to 3, the test section (100) is formed continuously between the downstream side of the contraction section (200) and the upstream side of the diffusion section (300), and is a key section that allows the flow of the wind tunnel device (1000) to act on the test object while maintaining the most homogeneous velocity field and target turbulence.

[0082] The test section (100) is an operating space for evaluating aerodynamic performance, evaluating the distribution and behavior of chemicals / aerosols (supplied by the supply section (600)), and performing sensor inspection and calibration, and is formed so that flow quality is maintained even when switching between open / circulating / parallel operation modes.

[0083] The cross-section of the test section (100) may be configured as at least one of a square, a circle, or an ellipse according to the embodiment, and in the case of a square cross-section, it may be formed to have an inner chamfer or a radius of curvature (R) to suppress flow separation at the corners.

[0084] The wall of the test section (100) can be formed of stainless steel (SUS304 / 316L), aluminum alloy (including corrosion-resistant coating), or a composite panel with excellent chemical resistance.

[0085] To reduce adsorption, desorption, and residual contamination in a chemical, biological, radiological, and nuclear (CBRN) test environment, a fluorine-based coating (e.g., PTFE-based), a ceramic coating, or a conductive anti-static coating may be optionally applied to the inner surface.

[0086] Double O-rings, gaskets (PTFE, FKM, etc.), and a design for maintaining positive / micro-negative pressure are applied to the joints of adjacent panels, ensuring prevention of external leakage in circulating mode and suppression of backflow or disturbance by outside air in open, circulating, and parallel modes.

[0087] An observation window may be placed on the side wall or top of the test section (100), and the observation window is composed of borosilicate glass, coated polycarbonate, etc., and has resistance to chemical substances.

[0088] The latching tension and frame distortion of the observation window are limited to satisfy optical quality flatness for laser optical measurements (PIV, LIF, etc.).

[0089] The inspection door includes an interlock device to prevent unintentional opening during operation and maintains airtightness through a gasket seal even during decontamination or discharge after the test is completed.

[0090] Inside the test section (100), a sting method, a post method, or a floor anchor rail is optionally provided to support the test object.

[0091] In the case of the sting method, to minimize flow disturbance, it can be penetrated in the rear flow area (diffusion section (300) side) and linked with the 6-component force balance.

[0092] A probe traverse rail is positioned along the ceiling or side wall, allowing the Pitot static tube, hot wire probe, sampling probe, etc. to be precisely transported in 3 axes or 2 axes.

[0093] Pressure tap arrays, temperature and humidity ports, and concentration sampling ports may be formed at regular intervals on the wall of the test section (100), and each port is sealed by a blank plug when not in use.

[0094] Chemicals / aerosols delivered from the supply unit (600) may be supplied to the test unit (100) through a test unit inlet manifold on the downstream side of the contraction unit (200), an upper side wall distribution nozzle array of the test unit (100), or a test unit shear ring-type distributor according to the embodiment.

[0095] The supply nozzle is oriented in an axial flow type (parallel to the flow direction) or at a fine angle (e.g., 0° to 15°) so as to spray within a range that does not impair the velocity uniformity of the test section (100), and if necessary, can be linked with a metering pump / mass flow controller (MFC) to enable concentration closed-loop control.

[0096] The discharge section (700) provides a discharge path from the test section (100) after the test is completed, and is connected to a high-performance filter / adsorbent to ensure minimal environmental diffusion.

[0097] In the parallel mode, the static pressure control of the blower (500) and the damper opening control of the discharge section (700) are coordinated to maintain the target static pressure within the test section (100) (multiple dampers are controlled simultaneously in a linked state to satisfy the flow rate, pressure, and velocity conditions within the wind tunnel), thereby preventing flow disturbance.

[0098] A static pressure sensor, a dynamic pressure sensor, a flow rate sensor, a temperature sensor, a humidity sensor, and a concentration sensor may be installed in the test section (100), and the sensor signals are provided in real time to a control section (not shown) to maintain reference values ​​such as speed, turbulence, and concentration.

[0099] In parallel mode, to suppress pressure fluctuations in the test section (100), the control section simultaneously optimizes the rotational speed of the blower (500), the detachment status of the corner duct (400), and the opening of the damper of the discharge section (700).

[0100] The inner surface of the test section (100) is continuously welded (full fillet / full penetration) and has a uniform coating film thickness so that residue is minimized after detoxification solution or gas purging.

[0101] A drainage or cleaning assist groove may be formed on the bottom surface, and drying purging is possible in conjunction with the operation of the discharge unit (700) after testing.

[0102] By applying a modular panel structure, damaged liners can be replaced in sections, and airtightness is ensured at the panel fasteners through torque management.

[0103] In addition, laser-blocking curtains or blinds can be installed around the observation window in preparation for laser measurement use, and they meet safety standards in conjunction with the door interlock.

[0104] To suppress electrostatic discharge, the test section (100) and the observation window frame are provided with a ground (earth) connection, and if necessary, the surface resistance is controlled by a conductive coating.

[0105] Meanwhile, the test section (100) can be modified to implement target Reynolds numbers of various scales through a variable cross-section (e.g., upper and lower wall movable type) or a replaceable liner.

[0106] A part of the test section (100) may include a temperature control jacket or a radiant heating / cooling panel to control thermal boundary conditions.

[0107] In the case of special experiments, a turbulence grid / vortex generator can be detachably installed upstream or inside the test section (100) to reproduce specified turbulence conditions (within a range where the degradation of flow quality is allowed).

[0108] The test section (100) is formed so that a circular mode, an open mode, or a parallel mode is selected by the mounting state of the corner duct (400).

[0109] In particular, in parallel mode, the test section (100) maintains the target static pressure / flow rate / concentration by the closed loop of the control section, so that pressure fluctuations and concentration dilution due to external air exchange do not exceed the allowable range.

[0110] As described above, the test section (100) accommodates the homogeneous flow formed in the contraction section (200) and the rectification section (800), and can implement the core functions of the present invention, such as Open / Closed circuit switching and parallel operation, without degradation of flow quality through interaction with the supply section (600), discharge section (700), blower (500), and corner duct (400).

[0112] The contraction section (200) is positioned in front of the test section (100) and increases the speed of the air and homogenizes the flow by gradually reducing the cross-sectional area of ​​the air passing through the rectification section (800).

[0113] This allows for the implementation of a more accurate and reproducible test environment within the test section (100).

[0114] The contraction portion (200) is designed with a smooth curved shape to prevent flow separation.

[0115] To explain in more detail, as shown in FIGS. 1 to 3, the contraction section (200) is positioned between the downstream side of the rectification section (800) and the upstream side of the test section (100).

[0116] The main function of the contraction section (200) is to accelerate and homogenize the airflow containing relatively low-speed turbulence formed in the rectification section (800) according to the contraction ratio, thereby providing the test section (100) with a flow having speed uniformity and low turbulence.

[0117] That is, the contraction section (200) is a key component that determines wind tunnel performance and ensures the accuracy and reproducibility of aerodynamic tests and chemical, biological, radiological, and nuclear tests performed within the test section (100).

[0118] The inner wall of the contraction section (200) is designed with a curved curvature, and a cubic curve or an exponential curve (e.g., a fifth-order polynomial, a Sebrian curve, an exponential profile, etc.) may be applied to minimize the occurrence of flow separation.

[0119] The contraction ratio (CR = A_in / A_out) of the contraction portion (200) is defined as the ratio of the outlet cross-sectional area (A_out) to the inlet cross-sectional area (A_in), and can be set in the range of about 4:1 to 12:1 depending on the embodiment.

[0120] Preferably, it has a range of 6:1 to 9:1, which is a value that takes into account the balance between velocity uniformity, turbulence reduction effect, and structural stability.

[0121] The exit cross-section has the same shape as the cross-section of the test section (100) and can be selected from square, circular, or elliptical.

[0122] The inner wall of the shrink portion (200) can be formed from at least one of stainless steel, aluminum alloy, and composite panel, and the surface is polished or coated with a fluorine-based coating to maintain a low roughness surface of Ra 0.8 μm or less, preferably Ra 0.4 μm or less.

[0123] For structural stability, the outer wall of the contraction section (200) is supported by a rib reinforcement structure or a grid frame and is formed to withstand differential pressure and vibration loads that occur during device operation.

[0124] A detachable panel structure can be adopted, making partial replacement, cleaning, or decontamination easy in the event of internal coating damage.

[0125] The contraction section (200) connects the rectification section (800) and the test section (100), and gradually removes residual vortices and non-homogeneous flow introduced from upstream.

[0126] The design goal of the contraction section (200) is to achieve a velocity distribution uniformity of ±1 to 3% at the test section inlet and a turbulence (TI) of 0.5 to 2% or less.

[0127] To this end, the inner wall of the contraction section (200) is formed with continuous curvature to ensure smooth acceleration of the flow and relief of the wall pressure gradient.

[0128] A static pressure port array may be installed around the outlet surface of the contraction section (200), thereby allowing real-time monitoring of the test section inlet conditions (flow velocity distribution, pressure distribution).

[0129] During a chemical, biological, radiological, and nuclear (CBRN) test, a concentration uniformity sensor (aerosol / chemical sensor) is placed at the inlet or outlet of the contraction section (200) to check whether the substance injected from the supply section (600) is sufficiently mixed or dispersed before entering the test section (100).

[0130] In some embodiments, a transparent observation window or a laser incident window is provided at the exit of the contraction section (200), so that optical measurement equipment such as PIV (Particle Image Velocimetry) and LDV (Laser Doppler Velocimetry) can precisely analyze the test section inlet conditions.

[0131] The supply unit (600) can be connected to the front or inside of the contraction unit (200).

[0132] For example, chemicals / aerosols can be uniformly injected into the test section through an array of distribution nozzles installed on the wall of the contraction section.

[0133] In this case, the supply material is rapidly mixed and diffused due to the effect of increasing the flow rate within the contraction section (200), so a uniform concentration distribution is formed within the test section (100).

[0134] The supply nozzle is oriented in an axial direction (parallel to the flow direction) so as not to impede flow homogeneity, and can be applied together with a turbulence grid or vortex suppression device if necessary.

[0135] The shrinking section (200) may have a chemical-resistant coating applied to its inner surface to facilitate decontamination and cleaning after chemical and biological testing, and a discharge / drying path is secured in conjunction with the operation of the discharge section (700).

[0136] The wall modules are connected in a segmented structure, allowing for partial replacement of damaged areas.

[0137] An inspection port for human access for internal inspection may be installed, and the inspection port may include an interlock device to prevent unintentional opening during operation.

[0138] In a closed circuit mode, the contraction section (200) ensures a stable velocity field between the rectification section (800) and the test section (100), thereby providing a uniform test environment without internal chemicals diffusing to the outside.

[0139] In open circuit mode, external air flows through the rectifier (800) and the contraction section (200) into the test section (100), so the contraction section (200) serves to accurately transmit external conditions to the test section.

[0140] In the hybrid mode, pressure fluctuations may occur during the process of some air being discharged to the outside, and the contraction section (200) performs the function of maintaining the uniformity of static pressure at the inlet of the test section (100) due to the designed pressure loss characteristics.

[0141] Accordingly, the contraction section (200) is a component that simultaneously achieves speed increase, homogenization, turbulence suppression, and uniform mixing of chemicals in the process of transmitting the flow introduced from the rectification section (800) to the test section (100).

[0142] In addition, it supports various operating modes suitable for testing purposes in conjunction with the supply unit (600) and the discharge unit (700), while maintaining the core performance of the wind tunnel device (1000).

[0144] The diffusion section (300) is located at the rear of the test section (100) and gradually expands the cross-sectional area of ​​the air passing through the test section to restore pressure and reduce the flow velocity.

[0145] The diffusion section (300) allows the air to move smoothly to the corner duct (400) and the blower (500) thereafter.

[0146] In addition, it plays a role in stabilizing the flow to ensure uniform circulation of internal chemicals during CBRN testing.

[0147] To explain in more detail, as illustrated in FIGS. 1 to 3, the diffusion section (300) is positioned downstream of the test section (100) and performs the function of decelerating the flow velocity and restoring static pressure by gradually expanding the cross-sectional area of ​​the air passing through the test section (100).

[0148] The diffusion section (300) is an important component that maintains the flow quality within the test section (100) while minimizing energy loss of the airflow within the wind tunnel device (1000), and stabilizes the flow after testing to smoothly transmit it to the corner duct (400) and the blower (500).

[0149] The inner wall of the diffusion section (300) is designed with a smooth expansion curve to prevent boundary layer peeling and the formation of a recirculation zone due to rapid expansion.

[0150] The diffusion angle (half-angle) is generally set in the range of 3° to 7°, and preferably designed to be 3.5° to 5° to ensure a balance between flow stability and pressure recovery rate.

[0151] It is preferable that the length (L) of the diffusion section (300) be designed to be in the range of 5H or more and 8H or less with respect to the height (H) of the test section outlet cross-section, so as to simultaneously satisfy pressure recovery efficiency and structural constraints.

[0152] The outlet cross-section of the diffusion section (300) is connected to the corner duct (400) or rectification section (800) that is subsequently connected, and is formed to match the overall cross-sectional shape of the wind tunnel, such as a rectangular, circular, or elliptical shape.

[0153] The wall of the diffusion section (300) can be formed of stainless steel (SUS304, SUS316L), aluminum alloy, or chemical-resistant composite panel, and a PTFE-based coating or ceramic coating can be applied to minimize the adsorption of chemicals that may remain inside during chemical and biological warfare testing.

[0154] For structural stability, rib reinforcement structures are installed on the exterior walls, and in the case of large wind tunnels, lattice frame reinforcement structures may be applied to withstand vibration and differential pressure loads.

[0155] To facilitate internal inspection, cleaning, and decontamination, some panels may be formed with a detachable modular structure.

[0156] The diffusion section (300) reduces the flow rate while maintaining the velocity uniformity formed in the test section (100) and maximizes the pressure recovery coefficient (Cp).

[0157] Generally, the design target pressure recovery rate is 0.6 or higher, preferably 0.7 to 0.8.

[0158] During a chemical, biological, radiological, and nuclear (CBRN) test, the chemical substance or aerosol injected into the interior undergoes re-mixing and dispersion effects as it passes through the diffusion section (300), so that the concentration measured in the test section (100) is stably maintained even at the rear end.

[0159] In some embodiments, a flow dispersion screen or a porous plate is installed inside the diffusion section (300) to suppress the generation of vortices and to control the turbulent characteristics downstream of the test section.

[0160] A static pressure port, a speedometer, and a concentration sampling port may be installed inside the diffusion section (300), through which the state of the air (speed distribution, concentration distribution, temperature, humidity) after testing can be checked.

[0161] If necessary, an observation window may be provided for laser optical measurement (PIV, LIF), and this is formed of borosilicate glass or a special polycarbonate material with chemical and pressure resistance.

[0162] A damper device connected to the discharge section (700) or corner duct (400) may be installed at the outlet of the diffusion section (300), thereby stably separating and controlling the flow when switching between the circulating mode and the open / parallel mode.

[0163] In some embodiments, a re-spray nozzle may be additionally installed at the inlet of the diffusion section (300) so that the chemical injected from the supply section (600) can be uniformly distributed even at the rear end of the test section (100).

[0164] The discharge section (700) is connected downstream of the diffusion section (300) to prevent the external diffusion of harmful substances through a filter and an adsorbent when air is discharged to the outside after the test is finished.

[0165] In the circulation mode, the air decelerated through the diffusion section (300) passes through the corner duct (400) and returns to the rectification section (800), and the internal circulation is maintained stably.

[0166] In open mode, the diffusion section (300) can be directly discharged to the outside through the discharge section (700) at the rear end, and in this case, rapid discharge and simulation of external conditions are possible.

[0167] In parallel mode, at the rear end of the diffusion section (300), some of the flow is separated into internal circulation and some into external discharge, and at this time, the stable pressure recovery performance of the diffusion section (300) ensures a balance of flow separation.

[0168] After the chemical and biological warfare test, the diffusion section (300) may be equipped with a drain and a cleaning port to facilitate internal cleaning and decontamination, and the surface is treated with a coating that is resistant to chemicals.

[0169] An inspection port is provided for internal access to facilitate cleaning and sensor replacement, and an interlock device is included to maintain airtightness during operation.

[0170] For vibration and structural stability, the diffusion section (300) is connected to the wind tunnel device frame and a multi-support structure, and an anti-vibration pad may be applied so that high-frequency vibrations are not transmitted to the test section.

[0171] Accordingly, the diffusion section (300) slows down and stabilizes the flow generated in the test section (100) and transmits it to the corner duct (400) and blower (500), while maintaining concentration uniformity and safety in the chemical, biological, radiological, and nuclear (CBRN) test.

[0172] In addition, it enables rapid switching without degradation of flow quality even when switching between circular, open, and parallel modes.

[0174] Corner ducts (400) are placed at the corner sections of each flow path and serve to deflect the airflow.

[0175] In particular, some of the corner ducts (400) of the present invention are formed to be detachable, and accordingly, the device is operated in the following modes.

[0176] When all corner ducts (400) are connected, it is a closed circuit mode in which air circulates only within the device.

[0177] When the corner duct (400) is removed or opened, it is an open circuit mode in which it is connected to the outside and air is discharged to the outside.

[0178] In the case where only some corner ducts (400) are connected, it is a hybrid mode in which some of the air is circulated internally and some is discharged externally.

[0179] The corner duct (400) can be easily detached and mounted, including a rail structure or a bolted structure, and the operating mode can be quickly changed according to the purpose of the test.

[0180] More specifically, as shown in FIGS. 1 to 3, the corner duct (400) is positioned at a point where the flow path of the wind tunnel device (1000) bends at a right angle and serves to smoothly divert the airflow.

[0181] Generally, the wind tunnel device includes a plurality of corner sections to form a closed circuit structure, and a corner duct (400) is placed in each of these.

[0182] In particular, some corner ducts (400) are formed to be detachable, and function as key components that allow the wind tunnel to be freely switched between a closed circuit mode, an open circuit mode, and a hybrid mode, or operated simultaneously.

[0183] The interior of the corner duct (400) is formed as a curved passage with a sufficient radius of curvature (R) to minimize flow separation and vortex generation when the air is switched at a right angle.

[0184] Guide vanes are positioned on the inner walls to guide the airflow to rotate smoothly.

[0185] At this time, the vane placement angle is optimized according to flow conditions and is formed to match the wind tunnel's target Reynolds number and turbulence characteristics.

[0186] The cross-sectional shape of the corner duct (400) can be formed in a square, circular, or elliptical shape to match the cross-section of the entire wind tunnel.

[0187] An important feature of the present invention is that at least one of the corner ducts (400) is formed to be detachable.

[0188] The connection part of the corner duct (400) includes a rail guide structure, a bolt fastening structure, or a hinge-locking structure, so that the operator can easily attach and detach it when switching the operation mode.

[0189] The detachable design is modular, allowing the entire corner duct to be removed or only a portion to be opened as needed.

[0190] Therefore, the wind tunnel can be rapidly switched between circular, open, and parallel modes.

[0191] In the circulation mode, when all corner ducts (400) are connected, air circulates only within the device, maintaining a stable test environment without external leakage.

[0192] In open mode, when the corner duct (400) is removed or partially opened, the flow inside the device is directly connected to the outside and operates like an open wind tunnel.

[0193] This is suitable for rapid discharge and ambient condition simulation tests.

[0194] In parallel mode, when only a part of the corner duct (400) is connected, some of the air travels along the internal circulation path and some is discharged to the outside.

[0195] This enables the implementation of a customized fluid environment suitable for the test purpose.

[0196] The corner duct (400) can be made of stainless steel (SUS304, SUS316L), aluminum alloy, or chemical-resistant composite material to withstand wear and corrosion caused by high-speed flow and repeated attachment and detachment.

[0197] The inner surface is treated with a chemical-resistant coating (PTFE, ceramic, etc.) to prevent the adsorption or residue of injected chemicals during CBRN testing.

[0198] To ensure airtightness of the detachable part, O-rings, gaskets, and sealing pads are applied to the connection part, and leakage is prevented even under internal wind tunnel pressure conditions.

[0199] In this embodiment, a sensor (e.g., proximity sensor, magnetic reed switch, optical sensor, etc.) for detecting whether the corner duct (400) is attached or detached may be attached.

[0200] The detected signal is linked to the control unit, so that the operating mode (circular, open, parallel) of the wind tunnel device (1000) is automatically switched or the safety interlock is activated.

[0201] This allows changes in the test environment to be reflected immediately without relying on manual operation by the operator.

[0202] Since the corner duct (400) can be frequently attached and detached, a lightweight design is applied so that the worker can easily detach and attach it.

[0203] In addition, a locking device and an interlock structure are provided to prevent unintentional separation during wind tunnel operation.

[0204] After the test is finished, the corner duct (400) can be detached to clean or decontaminate the interior, and only the damaged parts can be partially replaced using a module replacement method.

[0205] Due to the detachable structure of the corner duct (400), the wind tunnel device (1000) of the present invention can implement all three modes—circulating, open, and parallel—in a single device.

[0206] This overcomes the limitations of test range and safety inherent in existing single-mode wind tunnels, enabling various research and test objectives to be performed on a single platform.

[0207] Therefore, the corner duct (400) not only has the function of simply changing the flow direction, but also enables wind tunnel mode switching and parallel operation through a detachable structure.

[0209] The blower (500) is installed in conjunction with the corner duct (400) and is a power source that circulates air inside the device or draws in or discharges outside air.

[0210] The blower (500) includes a stationary fan and an electric motor, and maintains test conditions by controlling the air flow rate and pressure.

[0211] More specifically, as illustrated in FIGS. 1 to 3, the blower (500) is positioned in a section connected to the diffusion section (300) and the corner duct (400) and acts as the main power source for inducing or maintaining the entire airflow of the wind tunnel device (1000).

[0212] The blower (500) provides sufficient static pressure and airflow to secure the target flow rate in the test section (100), and maintains stable flow under various operating conditions such as a circulating mode, an open mode, and a parallel mode.

[0213] The blower (500) may be configured as an axial fan, a centrifugal fan, or a combination thereof, depending on the embodiment.

[0214] Due to the characteristics of wind tunnel testing, high flow rates and low turbulence are required; therefore, multi-blade axial fans are generally used, and aircraft profiles are applied to the blades to simultaneously satisfy efficiency and low noise.

[0215] The housing of the blower (500) can be formed in a bellmouth shape to minimize flow loss, and the inner wall is processed smoothly to prevent flow separation.

[0216] The blower (500) is driven by an electric motor, and depending on the size of the wind tunnel, the motor may be an induction motor, a permanent magnet synchronous motor (PMSM), or a variable speed drive (VFD) control motor.

[0217] By applying a variable frequency inverter (VFD) to precisely control the rotational speed of the blower, the target flow rate range of the test section (100) (e.g., 0.5 m / s to 150 m / s) can be achieved.

[0218] The control unit adjusts the rotational speed of the blower (500) in real time based on internal pressure, flow rate, and concentration sensor signals to suppress pressure fluctuations that may occur during mode switching.

[0219] To reduce mechanical vibration and noise generated by the blower (500), a vibration damping pad and sound-absorbing material may be applied to the outer surface of the housing.

[0220] The wing shape can be formed with a low-noise airfoil cross-section, and the tip clearance is minimized to suppress rotational noise and vortex generation.

[0221] Precision balancing and multi-bearing support are applied to the shaft system, ensuring stability even during long-term operation.

[0222] A protective mesh and suction guide vanes are placed in the suction part of the blower (500) to prevent foreign matter from entering and to improve suction efficiency.

[0223] The drive motor is equipped with an overload protection device, a temperature sensing sensor, and a current limiting circuit, so that it can be automatically stopped in the event of an abnormal situation.

[0224] The enclosure of the blower (500) can be formed of a high-strength metal or composite housing to prevent debris scattering due to high-speed rotation.

[0225] In the circulation mode, the blower (500) repeatedly circulates the air inside the device and maintains a constant pressure and flow rate.

[0226] In open mode, external air is sucked in, passes through the test section (100), and is then discharged to the outside, so the blower (500) supplies the amount of air necessary to reproduce the external air conditions.

[0227] In parallel mode, some air is circulated internally and some air is discharged externally, so the blower (500) controls the rotational speed in conjunction with the control unit to balance the static pressure in the two flow paths.

[0228] The blower (500) includes an inspection port for disassembly and maintenance to prevent a decrease in efficiency due to long-term operation, and the blades and housing have a modular structure that is easy to clean and replace.

[0229] Bearings are maintained via an automatic lubrication system or external lubrication ports, minimizing downtime during regular inspections.

[0230] A sensor that detects the operating condition (rotational speed, vibration, temperature) is installed on the outside of the blower (500), so that predictive maintenance is possible.

[0231] The blower (500) serves as a flow energy source for the wind tunnel device (1000) and supports high-precision control and operation in various modes.

[0232] Through this, the test conditions of the test unit (100) are always maintained within the target range, and a stable environment applicable to various fields such as chemical, biological, radiological, and nuclear testing and aircraft research testing is provided.

[0233] Accordingly, the blower (500) is not a simple air flow device, but a core power source of a multi-functional wind tunnel device, enabling precise control, low noise, and high-efficiency operation, and has a structure that can immediately respond to switching between circulating, open, and parallel modes.

[0235] The supply unit (600) is positioned between the diffusion unit (300) and the contraction unit (200) or in front of the test unit (100) and serves to supply chemicals or aerosols into the wind tunnel.

[0236] The supply unit (600) may include a chemical storage tank, a pump, a valve, piping, and a spray nozzle, and may optionally inject a substance in liquid, gaseous, or powder form into the test unit (100).

[0237] This allows for the simulation of various environmental conditions during chemical, biological, radiological, and nuclear (CBRN) testing.

[0238] More specifically, as illustrated in FIGS. 1 to 3, the supply unit (600) is connected to the test unit (100) of the wind tunnel device (1000) or the section in front thereof, and supplies a chemical substance or aerosol to the internal flow.

[0239] The supply unit (600) is primarily used in chemical, biological, radiological, and nuclear (CBRN) tests, aerosol permeability evaluations, filter performance tests, etc., and stably introduces a substance with a target concentration and distribution into the test unit (100) to simulate an actual operating environment.

[0240] This supply unit (600) may include a storage unit, a transfer unit, a distribution unit, etc.

[0241] The storage unit consists of a tank, cartridge, and cylinder for storing chemical substances or aerosol precursors, and can store at least one of liquid, gaseous, or powder states.

[0242] The transfer unit includes a pump (metering pump, diaphragm pump), a compressor, or a mass flow controller (MFC) to transfer the stored material to the test unit (100) at a desired flow rate and pressure.

[0243] The distribution section consists of piping, manifolds, nozzles, or porous injectors to uniformly disperse the supplied material into the wind tunnel flow.

[0244] The supply flow rate is adjusted in real time in conjunction with the control unit, and the target concentration can be automatically maintained based on the concentration sensor feedback.

[0245] The supply unit (600) can adopt various injection methods depending on the purpose of the test.

[0246] Liquid injection can be sprayed in the form of fine droplets through a spray nozzle, gas injection can be supplied in a gaseous state through compressed gas or an evaporator, and powder injection can be injected in the form of fine particles through a powder dispenser or an aerosol generator.

[0247] The injection nozzle is oriented parallel to the flow direction of the test section (100) (axial flow type) or at a certain angle (e.g., 5° to 15°) to induce uniform mixing without turbulent disturbance.

[0248] The supply flow rate is controlled in a closed-loop manner by the feedback signal of the concentration sensor and is adjusted so that the target concentration is maintained within ± 5%.

[0249] The storage section and piping of the supply section (600) are made of a chemical-resistant material (e.g., stainless steel, PTFE, PVDF, etc.) to minimize corrosion or adsorption by chemicals.

[0250] Each connection is equipped with a double seal structure (O-ring, gasket) to prevent leakage during operation.

[0251] If abnormal pressure or excessive flow is detected during chemical supply, the automatic shut-off valve operates to ensure safety.

[0252] The supply unit (600) is connected to the discharge unit (700) so that residual chemical substances are safely removed after the test is completed.

[0253] In an embodiment for chemical, biological, radiological, and nuclear testing, the supply unit (600) is configured to supply chemical simulant, toxic chemical simulant, etc., in a gaseous state.

[0254] In an example for an aerosol permeability test, the supply unit (600) includes an aerosol generator that generates standard particles such as NaCl, DOP, and PSL, thereby forming a uniform particle distribution in the test unit (100).

[0255] In a multi-supply embodiment, the supply unit (600) includes a plurality of storage units and injection nozzles, and can inject two or more types of chemicals simultaneously or sequentially.

[0256] In the circulating mode, the chemical injected from the supply unit (600) can maintain a constant concentration while circulating with the internal flow.

[0257] In this case, the concentration sensor and control unit monitor changes in concentration in real time and ensure stability.

[0258] In open mode, the chemical injected from the supply unit (600) passes through the test unit and is discharged to the outside, so rapid condition simulation and discharge are possible.

[0259] In parallel mode, some chemicals remain inside while others are released to the outside, allowing for the reproduction of various mixing conditions.

[0260] The supply unit (600) includes a drain port and a cleaning circuit so that the piping and storage unit can be cleaned after the test is finished.

[0261] The spray nozzle is designed with a detachable structure, allowing for quick replacement in the event of blockage or contamination.

[0262] The entire structure of the supply unit (600) is modularized so that the storage unit, transfer unit, and distribution unit can be replaced or inspected independently.

[0263] The supply unit (600) can stably and precisely introduce various chemicals and aerosols into the test unit (100), thereby greatly expanding the range of application of the wind tunnel device (1000).

[0264] This provides a platform optimized for multi-purpose research, including not only aircraft aerodynamic testing but also performance evaluation of CBRN protection equipment, blocking efficiency testing of filters and protective gear, and environmental condition simulation testing.

[0265] Therefore, the supply unit (600) is not a simple injection device, but an integrated supply system including storage, transfer, distribution, and control, which can realize the multifunctionality of the wind tunnel device.

[0267] The exhaust section (700) serves to discharge air from inside the wind tunnel to the outside after the test is finished.

[0268] The discharge section (700) includes a high-performance filter, an adsorbent, or a cleaning device to minimize the diffusion of internal chemicals to the outside.

[0269] In addition, controlling the discharge speed and direction enables rapid discharge and stable environmental recovery.

[0270] To explain in more detail, as shown in FIGS. 1 to 3, the discharge section (700) is positioned in the downstream section of the wind tunnel device (1000), that is, after the diffusion section (300) or the corner duct (400).

[0271] The exhaust unit (700) serves to discharge air inside the wind tunnel to the outside after the test is completed, and safely removes internal air while minimizing external diffusion, especially in test environments containing chemicals or aerosols.

[0272] In addition, the discharge section (700) is closed to maintain internal airtightness during circulating operation, and is opened to connect with the outside during open and parallel operation.

[0273] The discharge section (700) may include a discharge duct and valve, a filter section, an adsorbent cartridge, a discharge fan, a monitoring sensor, etc.

[0274] The exhaust duct and valve are passages for transporting air inside the wind tunnel to the outside, and are equipped with a damper or electric valve to control the opening and closing state.

[0275] The filter section includes a high-efficiency filter (HEPA, ULPA) or a multi-layer filtration filter to remove internal particulate matter and aerosols.

[0276] The adsorbent cartridge contains activated carbon, zeolite, and chemical adsorbents to adsorb or decompose gaseous chemicals.

[0277] The exhaust fan is used for forced exhaust to external atmospheric conditions and can operate in conjunction with a blower (500) or be driven independently.

[0278] A monitoring sensor is positioned at the outlet of the discharge section (700), with a concentration sensor and a pressure sensor, to confirm that the concentration of the chemical substance is below the safety standard before external discharge.

[0279] In the circulation mode, the exhaust unit (700) is kept closed so that internal air does not leak out.

[0280] The internal air is circulated through the blower (500), and the concentration within the test section (100) is maintained stably.

[0281] In open mode, the exhaust section (700) is fully open so that air passing through the test section (100) is quickly discharged to the outside.

[0282] At this time, the filter and adsorbent operate to minimize external diffusion.

[0283] In parallel mode, the exhaust section (700) is partially opened so that some of the internal air is discharged to the outside, and the rest circulates inside.

[0284] The control unit simultaneously controls the damper opening of the blower (500) and the discharge unit (700) so that the target pressure and concentration within the test unit (100) are maintained.

[0285] The filter of the discharge section (700) is composed of multiple stages, and can be discharged to the outside through a primary particle removal (HEPA), a secondary chemical adsorption (activated carbon), and a tertiary safety filter.

[0286] The filter and adsorbent are designed with a modular cartridge system, making replacement and decontamination easy.

[0287] If an abnormal situation (e.g., filter saturation, concentration exceeding) occurs, the discharge unit (700) is automatically shut off and a warning signal is generated.

[0288] A backflow prevention device is provided on the outside of the discharge section (700) to prevent external air from flowing back and causing internal contamination.

[0289] After the test is finished, the discharge unit (700) is equipped with a cleaning port and a drainage device capable of cleaning the interior, thereby minimizing chemical residue.

[0290] The inner walls of the exhaust path are treated with chemical-resistant material, so surface deterioration does not occur even after repeated decontamination.

[0291] During regular inspections, the filter, adsorbent cartridge, and valve status of the discharge unit (700) are recorded and managed, thereby ensuring the stability of the device for a long period of time.

[0292] The exhaust unit (700) goes beyond a simple exhaust device and safely discharges contaminated air inside the wind tunnel to the outside while minimizing environmental pollution.

[0293] Through this, the wind tunnel device (1000) ensures safety even in high-risk environments such as chemical, biological, radiological, and nuclear (CBRN) testing and filter performance testing, and can quickly return to a normal state after the test is completed.

[0294] Accordingly, the discharge unit (700) is an environmental protection and safety discharge system that determines the safety and reliability of the wind tunnel device, and can simultaneously achieve internal concentration control, prevention of external diffusion, and rapid discharge.

[0296] The rectification section (800) is positioned in front of the contraction section (200) and stabilizes the air flowing in from outside the wind tunnel and converts it into a uniform flow.

[0297] The rectification unit (800) may include a honeycomb structure, a screen, a porous filter, etc., and reduces the turbulent components of the air and enables a highly reproducible test in the test unit (100).

[0298] More specifically, as illustrated in FIGS. 1 to 3, the rectification unit (800) is positioned at the front of the wind tunnel device (1000) and serves to stabilize air introduced from the outside or circulated air and deliver it to the contraction unit (200).

[0299] The rectification section (800) determines the flow quality reaching the test section (100) by removing turbulent components in the flow, suppressing vortices, and homogenizing the velocity distribution.

[0300] In particular, even when external air is directly introduced in open mode or when the internal circulation flow and external air are mixed in parallel mode, the rectification unit (800) generates a uniform flow that meets the test conditions.

[0301] The rectification unit (800) includes a screen, a honeycomb, a filter unit, a flow guide, etc.

[0302] The screen consists of a multilayer metal mesh or composite mesh, which breaks down large-scale vortices and homogenizes the velocity distribution.

[0303] The honeycomb is installed in the center of the rectification section (800) and consists of a plurality of small-diameter passages to remove the lateral component of the flow and straighten the flow.

[0304] Generally, the slenderness ratio (L / D) is preferably in the range of 6 to 12.

[0305] The filter section may be equipped with a filter to remove large particles or impurities when external air is introduced.

[0306] In CBRN testing environments, HEPA-grade filters are applied to prevent the ingress of unnecessary external particles.

[0307] The flow guide (vane or cone) may include a structure that guides air to be uniformly distributed when it enters the rectification section.

[0308] The screen can be made of stainless steel, aluminum, copper, or synthetic materials with an anti-corrosion coating, and the honeycomb is formed from aluminum alloys, ceramics, composites, etc., and a fluoropolymer coating is applied if chemical resistance is required.

[0309] The outer wall of the rectification unit (800) is integrated with the wind tunnel body frame to ensure structural rigidity, and includes a modular screen and honeycomb cartridge for easy maintenance.

[0310] The rectification section (800) can be formed with the goal of reducing the turbulence to 0.5 to 2% or less.

[0311] By applying a multi-layer screen array (e.g., 2 to 3 layers), the flow can be gradually stabilized, and the lateral velocity in the final stage honeycomb can be suppressed to form a straight flow.

[0312] The air passing through the rectification section (800) has its velocity distribution homogenized before being accelerated in the contraction section (200), so that the reliability of the test in the test section (100) is greatly improved.

[0313] In the circulation mode, the internal circulation air passes through the rectification section (800) and is stabilized before entering the test section (100).

[0314] In this case, internal concentration maintenance and low-turbulence flow are achieved simultaneously.

[0315] In open mode, air directly introduced from the outside is prone to having turbulence and a non-uniform distribution, but as it passes through the multilayer screen and honeycomb of the rectification section (800), it becomes uniform and suitable for the conditions of the test section (100).

[0316] In parallel mode, even when the external flow and the internal circulation flow are mixed simultaneously, the rectification unit (800) stabilizes them to maintain the target conditions within the test unit (100).

[0317] The rectification unit (800) may be equipped with sensors for measuring inflow rate, pressure, temperature, and particle concentration, and the measured values ​​are provided to the control unit.

[0318] The measured data is linked to the control of the supply unit (600) and the discharge unit (700), so that the system is automatically adjusted to maintain the target concentration and flow rate during the test.

[0319] The screen and honeycomb of the rectifier (800) are modularized so that they can be quickly replaced if damaged or contaminated.

[0320] After the chemical and biological warfare test, cleaning and decontamination work is required, and corrosion by the cleaning solution is suppressed on the inside of the rectification unit (800) due to chemical-resistant coating and surface treatment.

[0321] An inspection access port is provided, allowing for checking for foreign matter accumulation during operation and cleaning regularly.

[0322] The rectification section (800) determines the initial quality of the flow in front of the wind tunnel device (1000) and ensures the performance of the test section (100) by removing turbulence and forming a uniform velocity distribution.

[0323] This ensures that test conditions remain constant even during operation in circular, open, and parallel modes, and improves reproducibility and reliability in various CBRN and aerodynamic tests.

[0324] Therefore, the rectification unit (800) is not a simple inlet duct, but a high-performance stabilization module that simultaneously achieves turbulence suppression and flow straightening, thereby substantially enabling multi-functional operation of the wind tunnel device.

[0326] A multi-functional wind tunnel device (1000) capable of Open / Closed circuit switching and parallel operation according to one embodiment of the present invention having the above configuration operates as follows.

[0327] Basically, by recirculating air internally through a circulating circuit, energy efficiency is increased and a constant test environment is provided.

[0328] If necessary, the corner duct (400) can be switched to an open mode by removing or opening a part of it to connect to the outside.

[0329] If only some corner ducts (400) are connected, a parallel mode in which a circular mode and an open mode are operated simultaneously can be implemented.

[0330] When a chemical substance or aerosol is supplied into the test section (100) through the supply section (600), the device provides an environment suitable for chemical, biological, radiological, and nuclear (CBRN) testing and evaluation.

[0331] After the test is finished, the internal air is quickly discharged to the outside through the discharge section (700), while minimizing environmental diffusion through the filter and adsorbent.

[0333] In other words, a multi-functional wind tunnel device (1000) capable of Open / Closed circuit switching and parallel operation according to one embodiment of the present invention is configured to include a test section (100), a contraction section (200), a diffusion section (300), a corner duct (400), a blower (500), a supply section (600), a discharge section (700), and a rectification section (800), as shown in FIGS. 1 to 3.

[0334] The device basically has a circular structure and can be freely switched and operated in circular, open circuit, and hybrid modes by attaching or detaching the corner duct (400).

[0335] The test section (100) is positioned in the central part of the wind tunnel device (1000) and is a section where the test subject is installed and interacts with the actual airflow.

[0336] A uniform flow accelerated in the contraction section (200) is introduced into the test section (100), and an environment with a target turbulence of 0.5 to 2% or less and a velocity uniformity of ±1 to 3% or less can be realized.

[0337] Additionally, the test section (100) can be formed of stainless steel, aluminum alloy, or composite material, and a chemical-resistant coating (PTFE, ceramic, etc.) is applied.

[0338] An observation window for optical measurement (PIV, LIF), a pressure port, and a concentration sampling port may be placed on the wall of the test section (100).

[0339] Chemical substances and aerosols are introduced from the supply unit (600) and are quickly discharged through the discharge unit (700) after the test is completed.

[0340] The contraction section (200) is located between the rectification section (800) and the test section (100), and gradually reduces the cross-sectional area of ​​the air to increase the speed and homogenize the flow.

[0341] The contraction portion (200) may have a smooth curvature 3rd to 5th order curve profile, and the contraction ratio may be set in the range of 4:1 to 12:1.

[0342] By means of the contraction section (200), velocity uniformity at the inlet of the test section (100), suppression of turbulence, and promotion of concentration mixing can be achieved.

[0343] A static pressure port and a concentration sensor are installed around the outlet, allowing for real-time monitoring of test conditions.

[0344] The modular inner wall structure makes cleaning and decontamination easy.

[0345] The diffusion section (300) is positioned downstream of the test section (100) and can reduce the flow velocity and restore static pressure by gradually expanding the cross-sectional area.

[0346] The diffusion angle is in the range of 3° to 7°, preferably 3.5° to 5°, and the pressure recovery coefficient can be achieved at 0.6 to 0.8 or higher.

[0347] The diffusion section (300) enables flow stabilization at the rear end of the test section, remixing of chemical substances, and smooth transfer to the corner duct (400).

[0348] It may include a pressure port, a concentration sampling port, and an optical measurement window internally.

[0349] In open / parallel mode, external discharge is possible by connecting to the discharge unit (700).

[0350] The corner duct (400) is configured to divert the airflow at a right angle and forms a circulation path for the wind tunnel device (1000).

[0351] It includes a passage with a secured radius of curvature and a guide vane to suppress flow separation and vortex generation.

[0352] It is fastened using one of the rail, bolt, or hinge-lock methods, and can be partially or entirely separated.

[0353] The operation mode is cyclic mode when all are connected, open mode when some are removed or opened, and parallel mode when only some are connected.

[0354] Automatic mode switching is possible from the control unit in conjunction with a sensor that detects whether the corner duct is attached or detached.

[0355] The blower (500) is the main power source that induces the flow of the wind tunnel device.

[0356] It is composed of an axial fan, a centrifugal fan, or a combination thereof, and high-efficiency, low-noise profile blades may be adopted.

[0357] The blower (500) is driven by an electric motor and a variable frequency drive (VFD) and controls the rotational speed to maintain the target flow rate of the test section (100).

[0358] Protective nets, overload protection, and vibration sensors may be applied, and are responsible for stable fluid energy supply in circulating, open, and parallel modes.

[0359] The supply unit (600) is a system for introducing a chemical substance or aerosol into the test unit (100).

[0360] The supply unit (600) consists of a storage unit (tank, cartridge), a transfer unit (pump, MFC), and a distribution unit (nozzle, manifold).

[0361] Injection in liquid (spray), gas (vapor), and powder (aerosol generator) forms is possible, and the target concentration can be maintained within ± 5% through sensor feedback-based closed-loop control.

[0362] It may include chemical-resistant materials, a double seal structure, and an overflow cutoff device.

[0363] The exhaust unit (700) is a device that discharges internal air to the outside after the test is finished.

[0364] The exhaust section (700) consists of an exhaust duct, a damper, a HEPA / ULPA filter, an activated carbon adsorbent, and an exhaust fan.

[0365] It minimizes the external diffusion of chemical substances and is closed in circular mode to maintain airtightness.

[0366] It features automatic shut-off upon detection of abnormal concentrations and a modular filter replacement structure, ensuring fast and safe discharge in open and parallel modes.

[0367] The rectification unit (800) stabilizes the incoming air or circulating air and delivers it to the contraction unit (200).

[0368] It may include a multi-layer screen, honeycomb, and, if necessary, filters and flow guides.

[0369] It has functions such as suppressing turbulence, eliminating transverse flow, and homogenizing velocity distribution, and can achieve a turbulence level of 0.5 to 2% or less and a velocity uniformity of ± 1 to 3%.

[0370] Modular replaceable structure, easy to decontaminate and clean.

[0371] Accordingly, the wind tunnel device (1000) is operated according to the following principle.

[0372] In the circulation mode, all corner ducts (400) are connected so that internal air circulates and the risk of external diffusion is minimized.

[0373] In open mode, some corner ducts (400) are removed and connected to the outside, allowing for rapid discharge and simulation of atmospheric conditions.

[0374] In parallel mode, some air circulates internally while some is expelled externally, allowing for the flexible implementation of various test conditions.

[0375] Through this, the present embodiment enables multi-purpose operation in a single device and can be optimized for various research purposes, such as chemical, biological, radiological, and nuclear (CBRN) testing, aircraft aerodynamic testing, and filter performance testing.

[0377] Meanwhile, a multi-functional wind tunnel device (1000) capable of Open / Closed circuit switching and parallel operation according to one embodiment of the present invention may include the following components.

[0378] The wind tunnel device (1000) according to the present embodiment may further include a cooperative control function that controls the degree of opening of the damper and the rotational speed of the blower (500) in real time so that the flow velocity inside the test section (100) maintains a target value.

[0379] Additionally, the wind tunnel device (1000) may include an emergency discharge mode that automatically opens the dampers of the corner duct (400) and the discharge section (700) to quickly discharge internal air to the outside when an abnormal situation occurs during a chemical injection test.

[0380] Additionally, the wind tunnel device (1000) may be configured such that the supply unit (600) is composed of multiple parts, allowing different types of chemicals or aerosols to be supplied simultaneously or selectively into the test section.

[0381] In addition, the wind tunnel device (1000) includes a multi-stage filtering system (e.g., HEPA filter, activated carbon adsorbent, chemical absorbent) in the discharge section (700) to minimize the diffusion of harmful substances to the outside after the chemical test is completed.

[0382] In addition, the wind tunnel device (1000) can be configured such that the test section (100), the contraction section (200), the diffusion section (300), and the corner duct (400) are modularized so that they can be replaced or expanded according to the purpose of the test.

[0383] In addition, the wind tunnel device (1000) can utilize an AI control algorithm based on data from multiple sensors installed inside to automatically select an optimal operating mode (Open / Closed / Parallel) according to the test purpose.

[0385] FIG. 4 is a schematic diagram showing the airflow in a circulating mode in a multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to one embodiment of the present invention.

[0386] A schematic illustration of the air flow (arrow “Wind flow”) when a multi-functional wind tunnel device (1000) capable of Open / Closed circuit switching and parallel operation according to one embodiment of the present invention is operated in a circulating mode is shown.

[0387] In the circulation mode, a closed circuit is fully formed with all corner ducts (400) installed, and the discharge section (700) is closed (or at least partially open) so that direct air exchange with the outside does not occur.

[0388] If necessary, the concentration inside the test section is set through the supply section (600), and the set concentration is maintained at a constant level while being recirculated inside the device.

[0389] In the flow from the blower (500) to the corner duct (400), the air discharged from the blower (500) changes its flow direction as it passes through the adjacent corner duct (400).

[0390] Flow separation and vortex generation are suppressed by the radius of curvature and guide vanes inside the corner duct (400), and the discharge flow is smoothly transferred to the next section.

[0391] In the flow from the corner duct (400) to the rectification section (800), the air passing through the corner duct (400) flows into the rectification section (800).

[0392] The rectification unit (800) includes a multilayer screen and a honeycomb to remove turbulent components and lateral velocity components and to equalize the velocity distribution.

[0393] At this time, the outer wall and joints of the rectification section are maintained as an airtight structure to prevent the mixing of external air.

[0394] In the flow from the rectification section (800) to the contraction section (200), the rectified air receives acceleration due to the reduction in cross-sectional area as it passes through the contraction section (200).

[0395] The curved profile of the contraction section (200) can be formed to mitigate the pressure gradient to prevent boundary layer delamination and to achieve velocity uniformity (e.g., ± 1 to ± 3%) and target turbulence (e.g., 0.5 to 2%) at the entrance of the test section.

[0396] In the flow from the contraction section (200) to the test section (100), the accelerated air flows into the test section (100) and acts on the test object.

[0397] In the test section (100), a model support device, an optical observation window, pressure, flow rate, concentration sensors, etc. are arranged as needed, and when the supply section (600) is in operation, the chemical substance or aerosol is distributed at a uniform concentration.

[0398] In the flow from the test section (100) to the diffusion section (300), the air passing through the test section (100) enters the diffusion section (300), decelerates as the cross-sectional area expands, and the static pressure is restored.

[0399] The diffusion section (300) is formed with a gentle diffusion angle to increase pressure recovery efficiency while suppressing the occurrence of a recirculation region.

[0400] In the flow from the diffusion section (300) through the corner duct (400) to the blower (500), the decelerated air passes through subsequent corner ducts (400) sequentially, the direction of flow is changed again, and finally returns to the suction side of the blower (500) for recirculation.

[0401] By maintaining such a path continuously, a closed-loop flow is formed as indicated by the arrow in Fig. 4.

[0402] In the circular mode, all detachable corner ducts (400) are connected, and the connection status is detected by a sensor (e.g., proximity sensor, reed switch, etc.).

[0403] The sensor signal is transmitted to the control unit to check the mode status.

[0404] Condition of the discharge section (700): The damper / valve of the discharge duct is closed or maintained at a minimum opening so that external discharge is blocked.

[0405] If necessary for safety, a leak monitoring sensor monitors the discharge line concentration.

[0406] The control unit variably controls the rotational speed of the blower to maintain the target flow rate of the test unit (100).

[0407] When a change in the fastening state of the corner duct (400) or a pressure fluctuation is detected, the rotational speed and the opening value of the internal damper are automatically corrected.

[0408] The supply unit (600) maintains the target concentration using closed-loop control with feedback from the concentration sensor.

[0409] In cyclic mode, since the substance is not discharged externally, it rapidly converges to the set concentration, and concentration fluctuations over time are small.

[0410] Through the continuous design of the rectification section (800), the contraction section (200), and the test section (100), the velocity uniformity, turbulence, and flow directionality are maintained within the specified range.

[0411] To suppress diffusion to the outside of the device during testing, the panel joints and inspection ports are equipped with a double seal structure (O-ring / gasket), and if necessary, the inside of the device is operated in a state of low negative pressure (relative to the atmosphere) to prevent external leakage.

[0412] One example of a driving procedure is as follows.

[0413] When setting the mode, check that the corner duct (400) is connected and the discharge section (700) is closed.

[0414] When starting and stabilizing, the blower (500) is started and stabilized at a portion of the rated flow rate, then ramped up to the target flow rate.

[0415] When setting conditions, the target concentration is set when the supply unit (600) is operated, and the control unit performs closed-loop control based on flow rate, pressure, and concentration sensor signals.

[0416] When performing the test, data acquisition (pressure, force / moment, optical measurement, etc.) is performed in the test section (100).

[0417] During the shutdown procedure, stop the supply, confirm the recovery of the internal concentration, slow down and stop the blower, and switch to the next mode (open type / parallel type) if necessary.

[0418] Since the air inside the device is repeatedly recirculated while external exhaust is blocked, the risk of diffusion into the environment is significantly reduced.

[0419] Long-term operation under identical conditions is possible, improving test reproducibility and data reliability.

[0420] When operating the supply unit (600), the concentration distribution is maintained stably, allowing for precise condition setting in chemical, biological, radiological, and nuclear (CBRN) tests and filter performance tests.

[0421] As described above, FIG. 4 illustrates the path and operating principle of a closed-loop flow (circulating mode) formed by the wind tunnel device (1000) of the present invention under the complete connection of the corner duct (400) and the closed state of the discharge section (700), and each of the above components (100~800, 500, 600, 700) can operate organically with one another to simultaneously ensure flow quality and safety.

[0423] FIG. 5 is a schematic diagram showing the airflow in an open mode in a multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to one embodiment of the present invention.

[0424] A multi-functional wind tunnel device (1000) capable of Open / Closed circuit switching and parallel operation according to one embodiment of the present invention is schematically illustrated with an air flow (arrow “Wind flow”) when operated in an open mode.

[0425] In open mode, at least one of the corner ducts (400) is detached so that the closed circuit is intentionally separated, and one side of the device operates as the outside air inlet side (suction side) and the other side as the outside air discharge side (discharge side).

[0426] At this time, the discharge section (700) is opened to provide a safe discharge path to the outside, and if necessary, a chemical substance or aerosol is introduced into the test section (100) through the supply section (600) to perform an external air condition simulation or an accelerated discharge test.

[0427] As shown in FIG. 5, a specific module on the downstream side of the corner duct (400) that formed a closed circuit is detached, and the location functions as an opening that communicates with the outside (see “Detachable” notation in the drawing).

[0428] The remaining corner ducts (420, 430, 440) maintain a connected state to minimize flow switching losses.

[0429] The discharge section (700) is opened so that air after passing through the test section (100) is safely discharged to the outside through the filter section and the adsorbent module.

[0430] The exhaust opening is varied by the command of the control unit.

[0431] The blower (500) is set to a rotational speed to stably maintain a unidirectional flow formed by the inflow of outside air, and the control unit synchronously controls the rotational speed of the blower and the opening of the discharge unit (700) according to the flow velocity, pressure, and concentration sensor signals.

[0432] Outside air is introduced into the device from the detached corner duct (400) or intake port.

[0433] As the incoming outside air passes through the multilayer screen and honeycomb of the rectification unit (800), the turbulent components and lateral velocity components are suppressed, and the velocity distribution is uniformized.

[0434] To prevent the mixing of foreign substances when outside air enters, a pre-filter may be placed upstream of the rectifier as needed.

[0435] The rectified flow passes through the contraction section (200) and accelerates as the cross-sectional area is reduced.

[0436] The curved profile of the contraction section suppresses boundary layer delamination, so that velocity uniformity of ± 1 to ± 3% and turbulence of 0.5 to 2% or less can be achieved at the entrance of the test section.

[0437] The accelerated flow flows into the test section (100) and acts on the test subject.

[0438] When the supply unit (600) is operated, a chemical / aerosol is introduced through a distribution nozzle on the front or inner side wall of the test unit and mixed with the external air flow, and a test is performed at a specified concentration and distribution.

[0439] The flow passing through the test section (100) is decelerated in the diffusion section (300) and the static pressure is restored.

[0440] The diffusion angle is set to suppress the formation of a recirculation zone, ensuring smooth transfer to the downstream discharge line.

[0441] The reduced flow is guided to the discharge section (700), where it sequentially passes through a HEPA / ULPA filter (removal of particulate matter) and an adsorbent such as activated carbon / zeolite (reduction of gaseous chemical substances) before being discharged to the outside.

[0442] The discharge section (700) is equipped with a backflow prevention structure to prevent backflow of external air.

[0443] The turbulent and non-homogeneous distribution caused by the inflow of outside air is corrected by the multilayer screen / honeycomb combination of the rectification section (800) and the curved profile of the contraction section (200), so that the flow quality of the test section (100) is maintained within the specified range.

[0444] The control unit corrects the rotational speed of the blower (500) and the opening of the discharge unit (700) in real time using the pressure / flow rate sensor signal of the test unit.

[0445] Through this, the target static pressure and flow rate of the test section (100) are maintained even when switching modes.

[0446] When operating the supply unit (600), the flow rate is controlled in a closed loop according to the concentration sensor value to maintain the target concentration, and the outlet concentration of the discharge unit (700) is monitored so as not to exceed the environmental standard value.

[0447] The diffusion of chemical substances into the outside air is minimized through the multi-stage filtration and adsorption system of the discharge section (700). Automatic shut-off and alarm occur when filter saturation or a concentration exceeding the regulated limit is detected.

[0448] The panel joints of the test section (100), shrinkage section (200), and diffusion section (300) maintain a double seal structure to suppress unintentional leakage to the outside.

[0449] If the corner duct (400) is not fully detached or the discharge unit (700) filter module is not installed, the control unit limits the operation of the blower (500) or the increase in the target flow rate.

[0450] One example of a driving procedure is as follows.

[0451] When preparing for mode switching, stop the circulating operation, detach the designated corner duct (400), and install the discharge section (700) filter / adsorbent module.

[0452] When starting and stabilizing the inflow of outside air, the blower (500) is started at a low speed to check the pressure and flow velocity downstream of the rectification section (800), and then raised to the target flow velocity.

[0453] When necessary, the supply unit (600) is activated to set the target concentration, and the test unit (100) performs measurements (pressure, force, flow rate, concentration, optics).

[0454] When discharging and stopping, the supply is stopped after the test is finished, and after sufficiently discharging the internal air through the discharge section (700), the blower (500) is stopped.

[0455] The corner duct (400) is reinstalled depending on whether the next mode (circular or parallel) is switched.

[0456] With external air inflow / outflow paths secured, test conditions can be changed and discharged quickly, enabling the implementation of scenarios that were difficult in conventional circulating wind tunnels, such as external atmospheric conditions, wind field simulation, and short-term high-concentration injection and discharge.

[0457] The multi-stage purification system of the discharge unit (700) and the interlock function of the control unit simultaneously ensure the safety of the external environment and the tester.

[0458] Accordingly, FIG. 5 clearly shows an open flow path formed by the detachment of the corner duct (400) and the opening of the discharge section (700), and indicates that a unidirectional flow leading to the rectification section (800), contraction section (200), test section (100), diffusion section (300), and discharge section (700) is stably maintained by the blower (500) and control section.

[0459] Through this, the wind tunnel device (1000) of the present invention can achieve high flow quality and safety even in tests requiring the simulation of external conditions and rapid discharge.

[0461] FIG. 6 is a drawing showing a detachable corner duct in a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to one embodiment of the present invention.

[0462] In a multi-functional wind tunnel device (1000) capable of Open / Closed circuit switching and parallel operation according to one embodiment of the present invention, an example is illustrated in which a corner duct (400) forming a rotation of the flow path is configured as a detachable module.

[0463] The corner duct (400) has a connecting flange with a square (or rectangular) cross section that engages with the upstream duct and the downstream duct, respectively, and a plurality of fastening holes (e.g., a plurality of bore patterns in the drawing example) are drilled at equal intervals on the outer circumference of the flange so that a tight and mechanical connection is ensured by bolt fastening.

[0464] The number, diameter, and pitch of the fastening holes are selected to suit design conditions such as flow rate, and the numerical values ​​and arrangement in the drawing are merely examples.

[0465] The casing of the corner duct (400) is formed as a curved flow path with a continuous radius of curvature connecting the upstream flange and the downstream flange, thereby suppressing boundary layer separation and recirculation when the flow is switched to 90° or the like.

[0466] The inner surface of the casing is processed to have a low surface roughness (e.g., Ra 0.8 μm or less) through polishing or coating treatment to minimize flow loss.

[0467] Multiple guide vanes (curved drift plates) that assist in changing the flow direction may be arranged inside the corner (see internal curve notation in Fig. 6), and the curvature, spacing, and number of vanes are optimized to match the target Reynolds number and turbulence.

[0468] The vanes are connected to the casing by welding or bolting.

[0469] A continuous gasket groove is formed along the perimeter of each flange face to mount an O-ring / elevator gasket.

[0470] As a result, external leakage in the circular mode is suppressed, and backflow and disturbance in the open / parallel mode are minimized.

[0471] The corner duct (400) can be connected to the upstream and downstream ducts with bolts / nuts through multiple fastening holes in the flange.

[0472] When fastening, alignment pins (examples of positions “A” and “B” in Fig. 6) or keyways are used to ensure concentricity and parallelism of the flanges and prevent step differences caused by assembly errors.

[0473] In the rail / guide method, sliding rails or guide shoes may be additionally provided on the outer casing to improve the workability of large modules.

[0474] With the combination of the rail and the base, the corner duct (400) can be quickly attached and detached in the order of horizontal movement → seating → bolt fastening.

[0475] A lifting eye / hook is placed on the corner or upper surface of the corner duct (400) (example marked “G” in FIG. 6) and is safely handled by a hoist.

[0476] Reinforcing ribs may be placed on the outer wall to prevent casing deformation during lifting.

[0477] A connection status detection sensor (proximity / lead / optical sensor, etc.) may be provided near the flange, and the sensor detects that the corner duct is fully connected and transmits a signal to the control unit.

[0478] When unfastened or incompletely fastened is detected, a safety interlock is activated to limit the start / speed increase of the blower (500) or to generate an alarm.

[0479] The casing and flange of the corner duct (400) can be formed of stainless steel (SUS304 / 316L), aluminum alloy, or chemical-resistant composite material.

[0480] To withstand chemical, biological, radiological, and nuclear (CBRN) testing, a fluoropolymer (PTFE) or ceramic coating may be applied to the inner surface, and plated / surface-treated bolts may be used to prevent corrosion of the fastening parts.

[0481] To reduce seal damage caused by repeated attachment and detachment, a double gasket or a replaceable seal cartridge may be used.

[0482] An inspection port / plug may be placed on the outer wall of the corner duct (400) to facilitate checking and cleaning the internal vane condition.

[0483] If necessary, a drainage port is formed at the bottom to perform drying and purging after discharging the cleaning water.

[0484] The module is manufactured with a split panel structure, allowing for partial replacement of only the damaged parts.

[0485] In the circulation mode, when the corner duct (400) is fully connected, a closed circuit is formed leading from the rectifier (800) - contraction section (200) - test section (100) - diffusion section (300) - corner duct (400) - blower (500), and recirculation is maintained without external leakage.

[0486] In open mode, when at least one of the corner ducts (400) is detached, the location is connected to the outside, and a unidirectional open flow is established in which outside air is introduced into the rectification section (800) and discharged to the outside through the discharge section (700).

[0487] In parallel mode, only some corner ducts are connected and others are detached to implement a flow in which internal circulation and external discharge occur simultaneously.

[0488] At this time, the control unit controls the rotational speed of the blower (500) and the opening of the discharge unit (700) in combination to maintain the target static pressure and flow rate of the test unit (100).

[0489] The flatness and parallelism of the flange surface, the spacing of fastening holes, and the alignment pin positions are managed according to KS / ISO flange tolerance standards or equivalent standards to suppress the step difference of the flange surface.

[0490] Torque management is performed during assembly, and after tightening, it can be confirmed that the leakage rate is below the allowable limit through a leak test (pressure retention / helium leakage, etc.).

[0491] Meanwhile, a variable pitch / angle structure of the guide vane and a split vane cartridge can be applied.

[0492] A structure in which one side is pivotally opened and closed using a hinge-swing method instead of a rail and the opposite side is fixed with a quick clamp may be adopted, and a quick-connection structure using a coupling band / ramp joint instead of a flange may be provided.

[0493] In addition, the internal cross-section of the Euro can be transformed into a circular, elliptical, or polygonal shape.

[0494] As described above, the detachable corner duct (400) of FIG. 6 functions as a core module that enables rapid and stable mode switching (circular / open / parallel) beyond a simple direction-changing element.

[0495] By ensuring various fastening means such as bolts and rails, airtightness through double seals, and safety through alignment, detection, and interlocking, the wind tunnel device (1000) of the present invention can simultaneously satisfy multi-functional operation and environmental and safety requirements.

[0497] FIG. 7 is a flowchart showing the overall flow of an operation method of a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to another embodiment of the present invention.

[0498] The multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation described above can be operated by the method of operating the multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to another embodiment of the present invention.

[0499] This method basically consists of the following procedures: flow formation → circuit configuration (detachable setup) → mode selection and operation → selected function (injection / discharge) → safety / termination; each step may be omitted, added, or have its order changed depending on the test purpose, safety standards, and equipment configuration.

[0500] In the initial preparation and self-diagnosis phase, before starting operation, the control unit self-checks for abnormalities in the corner duct (400) connection sensor, discharge unit (700) filter mounting detection, door interlock, blower (500) status, and sensors (pressure, flow rate, temperature, concentration).

[0501] If there are no issues, proceed to the next step.

[0502] If an anomaly is detected, an alarm is triggered, and main driving is prohibited until the cause is resolved.

[0503] In the first step (S100), the blower is started so that the air passing through the test section (100) flows through the blower (500).

[0504] The control unit applies a ramp profile for the target flow rate to gradually increase the rotational speed, and monitors the pressure and flow rate signals while passing through the rectification unit (800) and the contraction unit (200) to suppress sudden turbulence or pressure fluctuations caused by initial pressurization.

[0505] In this stage, if the reference static pressure of the test section (100) enters the set range, proceed to the next stage.

[0506] In the second stage (S200), flow is formed and stabilized by the contraction section (200) and the diffusion section (300) placed between the blower (500) and the test section (100).

[0507] The contraction section (200) increases the flow velocity by reducing the cross-sectional area and equalizes the velocity distribution, and the diffusion section (300) reduces the flow velocity downstream of the test section and restores static pressure.

[0508] The control unit reads the pressure distribution, turbulence, and velocity uniformity indices of this section and corrects the rotational speed of the blower (500) and the internal damper so that the test section inlet conditions fall within the specified values ​​(e.g., velocity uniformity ± 1 to ± 3%, turbulence 0.5 to 2% or less).

[0509] In the third step (S300), at least one of the multiple corner ducts (400) connecting the contraction section (200) and the diffusion section (300) is set to be detachable.

[0510] The connection status is detected by a connection sensor (proximity / lead / optical sensor, etc.) and transmitted to the control unit, and depending on the result, the flow can proceed to the next mode branch.

[0511] In the circulation mode, when it is determined that all corner ducts (400) are connected, the device is operated in the circulation mode.

[0512] At this time, the discharge section (700) is closed (or at least opened) to block air exchange with the outside, and the air inside the device is repeatedly recirculated within a closed circuit by the blower (500).

[0513] The control unit controls the blower rotation speed and internal damper in a closed loop so that the target flow rate and static pressure of the test unit (100) are continuously maintained.

[0514] When using the supply unit (600), the set concentration is stably maintained internally, and the discharge unit outlet concentration is constantly monitored, but in principle, discharge does not occur.

[0515] In open mode, if it is determined that at least one of the corner ducts (400) is removed (open), open mode is set.

[0516] Outside air is introduced through the rectification section (800), passes through the contraction section (200), the test section (100), and the diffusion section (300), and is discharged to the discharge section (700).

[0517] The discharge section (700) is opened to pass through a HEPA / ULPA filter and an adsorbent, and the control section maintains the target static pressure and flow rate of the test section (100) by synchronously controlling the rotational speed of the blower (500) and the opening of the discharge section.

[0518] Increased turbulence and non-uniformity of speed due to the introduction of outside air are corrected to within an allowable range through the design of the rectification section (800) and the contraction section (200).

[0519] In parallel mode, if it is determined that only a part of the corner duct (400) is connected, it is operated in parallel mode.

[0520] A portion of the internal air is discharged to the outside through the circulation path and the remainder through the discharge section (700), and external air is supplied as needed.

[0521] The control unit performs closed-loop control so that the target static pressure, flow rate, and concentration of the test unit (100) do not exceed the upper limit of fluctuation through multivariable correction between the rotational speed of the blower (500), the internal damper, and the opening of the discharge unit (700).

[0522] Meanwhile, depending on the purpose of the test, the supply unit (600) is activated to supply a chemical substance or aerosol to the test unit (100) in at least one form among liquid, gas, and powder.

[0523] The flow rate is set through a mass flow controller (MFC) or a metering pump, and is automatically corrected based on concentration sensor signals from the test section and the discharge section to maintain the target concentration (e.g., within ± 5% of the set value).

[0524] The nozzle orientation is set to an axial type or a small angle (e.g., 5 to 15°) to suppress flow disturbance.

[0525] After the open / parallel mode or test ends, the internal air is discharged to the outside through the exhaust unit (700).

[0526] In the discharge section (700), a multi-stage filter (particle removal) and an adsorbent (gaseous substance reduction) are applied sequentially, and if the outlet concentration exceeds a standard value, automatic shut-off and an alarm occur.

[0527] The backflow prevention structure prevents the backflow of external air.

[0528] During operation, the control unit constantly monitors key variables such as pressure, flow rate, temperature, concentration, corner duct connection status, door interlock, and filter saturation.

[0529] If a threshold is exceeded or an abnormal condition is detected, safety procedures are executed in stages, in the order of supply stop, discharge opening change, blower deceleration, and emergency stop.

[0530] Entry into the step of this method is blocked when the corner duct (400) is not connected, the exhaust filter is not installed, and the door is open.

[0531] When the test is finished, the supply unit (600) is stopped, and if necessary, internal air is discharged through the discharge unit (700) for a specified time to confirm that the background concentration is below the standard value.

[0532] Afterward, the blower (500) is decelerated and stopped, and when the user reconfigures the attachment / detachment of the corner duct (400) according to the next test scenario, the same flow can be repeated to immediately switch to another mode (circulating / open / parallel).

[0533] The above steps may be partially omitted or performed in parallel depending on the purpose.

[0534] For example, in parallel mode, supply and discharge are performed simultaneously to maintain a constant target concentration while allowing for simultaneous external discharge, and in circular mode, supply can be omitted.

[0535] As described above, the operation method according to FIG. 7 is configured to quickly and safely implement selective switching of circulating / open / parallel modes and parallel operation in a single device (1000) through mode branching based on the detachable state of the corner duct (400) and cooperative control of the blower (500), discharge unit (700), supply unit (600), and sensor / control unit.

[0536] This enables the simultaneous assurance of reproducibility and safety for various test purposes (CBRN performance evaluation, simulation of ambient conditions, filter / protective equipment testing, etc.).

[0538] As such, the present invention has the effect of overcoming the structural and operational limitations of existing wind tunnels and providing a multi-purpose test environment capable of responding to various test purposes.

[0539] In addition, according to the present invention, since closed circuit, open circuit, and hybrid operation modes can be selectively implemented in a single device, the necessary operation method can be immediately switched according to the test purpose, thereby providing significantly higher flexibility compared to existing wind tunnels with a single operation method and having the effect of enabling various test scenarios to be performed in a single device.

[0540] In addition, according to the present invention, since wind tunnel circuit switching is rapidly performed through a simple detachable corner duct structure, the test environment can be changed quickly, thereby shortening test preparation time and enabling efficient execution of continuous tests under various conditions, while reducing the burden on research personnel and improving overall test productivity.

[0541] In addition, according to the present invention, when operating a circulating circuit, air exchange with the outside is blocked, thereby minimizing the risk of chemicals or contaminants injected into the wind tunnel spreading to the outside. Furthermore, since the internal air can be immediately switched to an open circuit to be discharged to the outside when necessary, rapid discharge and purification are possible after the test is completed, which has the effect of significantly improving safety for researchers, test equipment, and the external environment.

[0542] In addition, according to the present invention, since multi-purpose operation is provided with a single wind tunnel device, the spatial and economic burden of having to construct an open wind tunnel and a circulating wind tunnel separately as in the past can be drastically reduced, thereby reducing installation costs, maintenance costs, and operating costs, and enabling the efficient utilization of resources by research institutions or test and evaluation institutions.

[0543] Furthermore, according to the present invention, it can be optimized and utilized not only in traditional aerodynamic testing fields such as aircraft or vehicles, but also in chemical, biological, radiological, and nuclear (CBRN) protection equipment testing and evaluation, environmental simulation testing, and special-purpose airflow control experiments. Since it can provide a customized flow environment tailored to specific test purposes through a parallel operation mode, it has the effect of enabling complex environmental testing that was difficult to perform in conventional wind tunnels.

[0544] Furthermore, according to the present invention, by simultaneously achieving effects such as multi-functional operation tailored to the test purpose, improved test efficiency, enhanced safety, economic feasibility, and expanded usability, it is possible to provide a new paradigm for providing test environments in the field of wind tunnel technology.

[0546] Although various preferred embodiments of the present invention have been described above with some examples, the descriptions of various embodiments described in the "Specific details for carrying out the invention" section are merely illustrative, and those skilled in the art to which the present invention pertains will understand that the present invention can be modified in various ways or equivalent embodiments can be carried out based on the above description.

[0547] In addition, since the present invention can be implemented in various other forms, the present invention is not limited by the description above. The above description is provided merely to make the disclosure of the present invention complete and to fully inform those skilled in the art of the scope of the present invention, and it should be understood that the present invention is defined only by each claim of the claims. Explanation of the symbols

[0549] 100 : Test section 200 : Contraction part 300 : Diffusion part 400 : Corner duct 500 : Blower 600 : Supply unit 700 : Discharge part 800 : Rectifier 1000: Multifunctional wind tunnel device capable of open / closed circuit switching and parallel operation

Claims

Claim 1 A multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, comprising: a test section; a blower for flowing air through the test section; a contraction section and a diffusion section disposed between the blower and the test section; and a plurality of corner ducts connecting the contraction section and the diffusion section to allow air to circulate inside the device; wherein at least one of the corner ducts is formed to be detachable; when all corner ducts are connected, the device operates in a circulating mode in which air circulates only inside the device; when the corner ducts are removed or partially opened, the device operates in an open mode in which the internal flow is directly connected to the outside; and when only a part of the corner ducts is connected, the device operates in a parallel mode in which a portion of the air moves along an internal circulation path and a portion is discharged to the outside, thereby operating in parallel with the circulating mode and the open mode. Claim 2 delete Claim 3 delete Claim 4 A multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, characterized in that, in claim 1, the corner duct includes a rail structure or a bolt fastening structure. Claim 5 A multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, characterized in that, in claim 1, it includes a sensor for detecting whether the corner duct is attached or detached, and the wind tunnel operation mode is automatically controlled according to the signal of the sensor. Claim 6 A multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, characterized in that, in claim 1, it further comprises a control unit that controls an operating mode based on the measured values ​​of the sensors, and includes a plurality of sensors for detecting internal pressure, temperature, humidity, flow rate, and chemical concentration. Claim 7 A multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, characterized in that, in claim 1, it further includes a supply unit for supplying a chemical substance or aerosol into the test section. Claim 8 A multifunctional wind tunnel device capable of Open / Closed circuit switching and parallel operation, characterized in that, in claim 7, the supply unit is configured to selectively supply chemicals in liquid, gaseous, or powder form. Claim 9 A multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, characterized in that, in claim 1, it further includes an exhaust section for discharging internal air to the outside after the test is completed. Claim 10 A multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, characterized in that, in claim 9, the discharge section comprises a filter or an adsorbent and is configured to minimize diffusion into the environment when internal chemicals are discharged to the outside. Claim 11 A method for operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, comprising: a first step in which air passing through a test section is flowed by a blower; a second step in which an air flow is formed by a contraction section and a diffusion section disposed between the blower and the test section; and a third step in which at least one of a plurality of corner ducts connecting the contraction section and the diffusion section is formed to be detachably attached; wherein, when all corner ducts are connected, the device is operated in a circulating mode in which air circulates only within the device; when the corner ducts are removed or partially opened, the device is operated in an open mode in which the internal flow is directly connected to the outside; and when only a part of the corner ducts is connected, the device is operated in a parallel mode in which a portion of the air moves along an internal circulation path and a portion is discharged to the outside, thereby operating in parallel with the circulating mode and the open mode. Claim 12 delete Claim 13 delete Claim 14 A method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, characterized in that, in claim 11, the corner duct includes a rail structure or a bolt fastening structure. Claim 15 A method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, wherein, in claim 11, a sensor detecting whether the corner duct is attached or detached, and the wind tunnel operation mode is automatically controlled according to the signal of the sensor. Claim 16 A method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to claim 11, characterized by further including a control unit that controls an operating mode based on the measured values ​​of the sensors, and a plurality of sensors that detect internal pressure, temperature, humidity, flow rate, and chemical concentration. Claim 17 A method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, characterized in that, in claim 11, it further includes a supply unit for supplying a chemical substance or aerosol into the test unit. Claim 18 A method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, wherein, in claim 17, the supply unit is configured to selectively supply a chemical substance in the form of a liquid, gaseous, or powder. Claim 19 A method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, characterized in that, in claim 11, it further includes an exhaust unit for discharging internal air to the outside after the test is completed. Claim 20 A method of operating a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, wherein, in claim 19, the discharge section is configured to include a filter or an adsorbent to minimize diffusion into the environment when internal chemicals are discharged to the outside. Claim 21 A multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation, characterized by operating according to a method of operation of a multi-functional wind tunnel device capable of Open / Closed circuit switching and parallel operation according to any one of claims 11, 14 to 20.

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