JP2011122992A - Vertical wind tunnel device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simplified wind tunnel device that facilitates dismantling, assembling and conveying. <P>SOLUTION: The vertical wind tunnel device includes an air introduction part, a first flow straightening part, a flow contraction part, a transparent cylindrical visualization test part, a second flow straightening part, and an air flow generation part. The device is formed by piling and bonding in the vertical direction, each part constituted separably and bondably. The visualization test part has a cylindrical shape, so that disturbance is hardly generated from an inner wall of the wind tunnel. Also, the device is installed vertically so as to make air flow in the vertical downward direction, thereby deviation between a tracer locus and a streamline of the air flow can be suppressed minimally. Further, the device can be assembled, dismantled and operated very easily, so that it is most suitable for an experimental device used in a physical/chemical education field for school students. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wind tunnel device that visualizes the flow of airflow, and more particularly to a simple wind tunnel device that is easy to disassemble, assemble, and transport.

  Conventionally, wind tunnel experiments have been performed for various purposes in which a test object such as a reduced model is placed in an artificially generated gas flow, and the gas flow is visualized and observed. Generally, in a wind tunnel experiment, a tracer is used to visualize the gas flow. However, since the specific gravity of the tracer is usually different from that of the fluid, the tracer trajectory and the actual gas stream line may be misaligned. .

  In this regard, Japanese Patent Laid-Open No. 5-264297 (Patent Document 1) introduces a heated gas into the wind tunnel, thereby making the density of the inflowing gas and the density of the tracer (smoke) substantially equal, and the tracer itself Although the streamline observing wind tunnel that is prevented from being lifted by the buoyancy of the air is disclosed, the configuration of the device of Patent Document 1 must be complicated.

  In addition, the conventional wind tunnel generally has a square cross section, so there is a problem that air flow is likely to be disturbed from the four corners of the inner wall, and many of the conventional wind tunnel experimental devices are large-scale. Therefore, it was difficult to conduct wind tunnel experiments casually in everyday spaces such as classrooms.

Japanese Patent Laid-Open No. 5-264497

  The present invention has been made in view of the above problems in the prior art, and an object of the present invention is to provide a simple wind tunnel device that can be easily disassembled, assembled, and transported.

  As a result of intensive studies on a simple wind tunnel device that can be easily disassembled, assembled, and transported, the inventor has configured the visualization test section as a transparent cylindrical member and installed it vertically to allow the flow of airflow. The present inventors have found that by making the direction vertically downward, it is possible to suppress the turbulence generated from the inner wall of the wind tunnel and to minimize the deviation between the tracer trace and the streamline of the air flow.

  That is, according to the present invention, the vertical wind tunnel is provided with a transparent cylindrical visualization test unit installed vertically, and the flow direction of the air flow in the visualization test unit is set vertically downward An apparatus is provided. Further, according to the present invention, a longitudinal section including an air introduction section, a first rectification section, a contracted flow section, a transparent cylindrical visualization test section, a second rectification section, and an airflow generation section. This type of wind tunnel device is formed by stacking and joining the parts configured to be separable and joinable in the vertical direction, and the visualization test part is vertically arranged so that the airflow direction is vertically downward. A vertical wind tunnel device is provided that is installed at a stand. In the present invention, the above-mentioned portions can be joined without being bolted by fitting. Further, in the present invention, the visualization test part can be formed by an acrylic pipe, and a support column for fixing a test object is provided in an internal space of the visualization test part, and the support column Can be configured to be rotatable. Furthermore, in the present invention, the rectifying portion can be formed of a honeycomb member.

  As described above, according to the present invention, a vertical wind tunnel device that can be easily disassembled, assembled, and transported is provided. In the vertical wind tunnel device of the present invention, it is possible to suppress the turbulence generated from the inner wall of the wind tunnel and to minimize the deviation between the tracer trace and the stream line of the air flow.

The figure which shows the vertical wind tunnel apparatus of this embodiment. The figure which shows the relationship between the flow direction of an airflow, and the trace of a tracer. The figure which shows sectional drawing of the vertical wind tunnel apparatus of this embodiment. The conceptual diagram which shows the mode of replacement of a test object. The conceptual diagram which shows the mode of decomposition | disassembly and accommodation of the vertical wind tunnel apparatus of this embodiment. The figure which shows the optical system of the vertical wind tunnel apparatus of this embodiment. The figure which shows the result of the wind tunnel experiment by the real machine of a vertical wind tunnel apparatus.

  Hereinafter, the present invention will be described with reference to embodiments shown in the drawings, but the present invention is not limited to the embodiments shown in the drawings. In the drawings referred to below, the same reference numerals are used for common elements, and the description thereof is omitted as appropriate.

  FIG. 1 shows a vertical wind tunnel device 10 according to an embodiment of the present invention. The vertical wind tunnel device 10 includes an air introduction unit 12, a first rectification unit 13, a contraction unit 14, a visualization test unit 16, a second rectification unit 18, and an airflow generation unit 20. Composed. In this embodiment, the air introduction part 12 is comprised by the truncated cone-shaped cylindrical hood, and all the 1st rectification | straightening parts 13 and the 2nd rectification | straightening part 18 are comprised by the rectangular parallelepiped honeycomb member. The airflow generation unit 20 includes a propeller fan 22, a slidac 24 for controlling the rotation of the propeller fan 22, and a pedestal 26 for placing the propeller fan 22.

  The rectifying units 13 and 18 in the present embodiment are preferably composed of a honeycomb having appropriate fineness and thickness so that a sufficient rectifying effect can be obtained. Further, if the rectifying sections 13 and 18 are made of an aluminum honeycomb, it is advantageous because a fired incense stick (tracer) can be placed directly on the upstream rectifying section 13 (honeycomb). Even if a burned incense stick or a test object falls, the presence of the rectifying unit 18 (honeycomb) on the downstream side prevents them from hitting the propeller fan 22 directly. Further, in the present embodiment, it is preferable to reduce the upper part of the vertical wind tunnel device 10 by forming the air introduction part 12 and the contracted flow part 14 with a light material such as plastic or tinplate. In the present embodiment, since the heavy airflow generating unit 20 is disposed at the lowermost part, the entire apparatus is stabilized by reducing the weight of the upper part, and as a result, disassembly and assembly accompanying the attachment / detachment of the test object is easy. become.

  The visualization specimen 16 in the present embodiment is configured by a transparent cylindrical member. Examples of the transparent cylindrical member that can be used include an acrylic pipe that is a general-purpose member. A specimen support column 30 for fixing the specimen is projected in the internal space of the visualization specimen 16, and the specimen support column 30 is configured to be rotatable by a rotation driving means 32 such as a motor. Yes. In the present embodiment, by arranging the cylindrical vortex propagation preventing portion 17 between the propeller fan 22 and the second rectifying portion 18, the effect of the rotation of the flow caused by the rotation of the propeller fan 22 is visualized. It is guaranteed not to reach the test part 16. The vortex propagation preventing part 17 can also be made of the same member (acrylic pipe) as the visualization test part 16.

  As mentioned above, although the component of the vertical wind tunnel apparatus 10 of this embodiment has been described, the materials, shapes, and components that constitute the air introduction unit 12, the rectification units 13 and 18, the current reduction unit 14, and the airflow generation unit 20 described above. About parts etc., what is necessary is just to perform the function equivalent to the function which it performs in the conventional wind tunnel device, and it cannot be overemphasized that various design changes are possible about the detailed composition of each part. Further explanation is omitted.

  The vertical wind tunnel device 10 of the present embodiment is characterized in that the visualization specimen 16 is configured in a cylindrical shape. Many of the conventional wind tunnel devices employ a rectangular parallelepiped visualization test section, so that air currents are likely to be disturbed from the four corners of the inner wall. In that respect, in this embodiment, since the cylindrical visualization test part is employed, the disturbance generated from the inner wall surface of the wind tunnel can be minimized.

  Further, the vertical wind tunnel device 10 of the present embodiment is characterized in that the flow direction of the airflow is a vertically downward direction. In this embodiment, as shown in FIG. 1, each component is piled up in the vertical direction, and the visualization test part 16 is installed vertically. In the vertical wind tunnel device 10 stacked in this manner, the airflow flows down vertically in the visualization test section 16. The tracer T generated from a tracer generation source (not shown) arranged in the air introduction unit 12 flows down in the visualization test unit 16 following the airflow flowing down in the vertical direction. At this time, the streamline of the airflow can be observed as the trace of the tracer T by irradiating the visualization test unit 16 with light from a light source (not shown).

Here, the significance of setting the airflow direction as the vertically downward direction will be described below with reference to FIG. In FIG. 2, the flow direction of the airflow is indicated by a white arrow, and the tracer trace is indicated by a broken arrow. Since the visualization test part in the conventional wind tunnel device keeps the flow direction of the air flow horizontal, the following problems occur. For example, when a tracer T _L having a specific gravity smaller than that of air such as incense smoke is used, the tracer T _L is displaced from the streamline as it goes downstream as shown in FIG. while thus, when using the tracer T _H specific gravity than air is large as in the dry ice smoke (carbon dioxide), as shown in FIG. 2 (b), as toward the downstream, the tracer T _H is streamlined In any case, there is a problem that the streamline cannot be accurately visualized.

  About this point, the vertical wind tunnel apparatus 10 of this embodiment makes the flow direction of an air flow and the action direction of gravity correspond by installing a visualization test part vertically. As a result, as shown in FIG. 2C, the deviation between the tracer trajectory and the streamline can be minimized regardless of whether the specific gravity of the tracer is lighter or heavier than air. Enables accurate visualization of lines. It is also advantageous to reduce the installation area by placing the device vertically. The two features of the vertical wind tunnel device 10 of the present embodiment have been described above. Next, FIG. 3 illustrates the third feature of the vertical wind tunnel device 10 of the present embodiment, which is the convenience in use. Hereinafter, description will be made with reference to FIG.

  FIG. 3 shows a cross-sectional view of the vertical wind tunnel device 10 of the present embodiment. In addition, in FIG. 3, the flow direction of airflow is shown by the white arrow line. In the example shown in FIG. 3, negative pressure is generated in the vertical wind tunnel device 10 by the rotation of the propeller fan 22, and air flows into the device from the air introduction unit 12. The air flowing in from the air introduction unit 12 is rectified and contracted through the first rectification unit 13 and the contraction unit 14 and then introduced into the visualization test unit 16. The air introduced into the visualization test section 16 flows downward in the vertical direction, passes through the second rectification section 18 and the vortex propagation prevention section 17, and is exhausted from the opening provided in the base 26. In the vertical wind tunnel device 10 of the present embodiment, a so-called suction type in which a propeller fan 22 is provided on the downstream side of the visualization test unit 16 is employed, and further, a second rectification unit is provided on the downstream side of the visualization test unit 16. 18 is provided, the visualization test part 16 has a structure that is not easily disturbed by the propeller fan 22. Moreover, the disturbance of the outside air that has flowed in from the air introduction unit 12 is suppressed by the first rectification unit 13 provided on the upstream side of the visualization test unit 16, and is disturbed by the visualization test unit 16 via the contraction unit 14. It is introduced as a uniform flow without any.

  Here, in the present invention, it is of course possible to configure the components of the vertical wind tunnel device 10 to be fixed with bolts or the like, but in the present embodiment, the components are stacked in the vertical direction. Adopting a boltless joining structure. In the example shown in FIG. 3, the constituent members of the vertical wind tunnel device 10 are joined to each other in a boltless manner by fitting as shown by being surrounded by a broken line. In this embodiment, since each component member is piled up in the perpendicular direction, each weight acts on each joint. Therefore, even if the components are simply loosely fitted, the overall stability of the device can be obtained without any problem in the wind tunnel test. In this way, by constructing the apparatus without bolts, simple assembly and disassembly are possible. In addition, when adopting a honeycomb member for the rectifying units 13 and 18, the honeycomb member that is difficult to be processed is cut by sandwiching the honeycomb member with two plates (13a and b and 18a and b) having holes. However, it is possible to form a recess for fitting each component member.

  Being boltless is convenient, for example, when replacing the test object. That is, in the vertical wind tunnel device 10 of the present embodiment, when replacing the test object (● → ★), as shown in FIG. 4, from the top, the air introduction unit 12, the first rectification unit 13, It is possible to replace the test object by placing the hand in the visualization test section 16 simply by releasing the fitting in the order of the contraction section 14, and after the replacement, the contraction section 14 and the first rectification section 13 are replaced. This is convenient because the next wind tunnel experiment can be carried out immediately after re-fitting in the order of the air introduction part 12.

  Furthermore, when not in use, the vertical wind tunnel device 10 of the present embodiment can be immediately disassembled and stored in a predetermined dedicated case 50, as shown in FIG. It is also easy to transport it.

  Next, an embodiment of an optical system applicable to the vertical wind tunnel device 10 of the present embodiment will be described with reference to FIG. Prepare a glass surface of a commercially available projector 60 (for example, a halogen lamp) by attaching plates 62 and 62 with a slit having an appropriate width (for example, about 30 mm) left. On the other hand, a cylindrical transparent container 64 (for example, an acrylic container) filled with water is made to function as a condensing lens, and the light emitted from the slit is visualized through the transparent container 64 as a visualization test of the vertical wind tunnel device 10. Irradiate the part 16. By constructing the optical system according to such a procedure, the manufacturing cost of the apparatus can be reduced. Furthermore, the water stored in the transparent container 64 can be used for fire prevention as a preparation for an unexpected fire caused by an incense stick (tracer).

  In addition, a commercially available plastic flower pot or the like is used for the air introduction section 12 or the contraction section 14, and a household ventilation fan is used for the airflow generation section 20 (propeller fan 22), or a commercially available fan instead of the slidac. If the rotation control device is used, the entire vertical wind tunnel device 10 of the present embodiment can be manufactured at low cost.

  As described above, the vertical wind tunnel device of the present invention can be easily manufactured at low cost using an existing general-purpose material, and enables full-scale streamline observation. In addition, the vertical wind tunnel device of the present invention is easy to assemble, disassemble, and operate, so it is optimal for an experimental device used in physical and chemical education for elementary, middle and high school students. In addition to educational purposes, the vertical wind tunnel device of the present invention will be very useful for users who want to conduct simple wind tunnel experiments at low cost.

  As described above, the present invention has been described with the embodiment. However, the present invention is not limited to the above-described embodiment, and other functions and effects of the present invention are within the scope of embodiments that can be considered by those skilled in the art. As long as the above is achieved, it is included in the scope of the present invention.

  Hereinafter, although the vertical wind tunnel apparatus of the present invention will be described more specifically with reference to examples, the present invention is not limited to the examples described later.

  An actual vertical wind tunnel device equivalent to that shown in FIG. 1 was produced. In this example, an aluminum honeycomb having a cell size of 1/8 inch and a thickness of 80 mm was used as the rectifying unit. Further, for the visualization test part, three types of actual machines were prepared using transparent acrylic cylinders with three types of diameters (80 mm, 190 mm, 250 mm). A wind tunnel experiment was carried out using each of the produced actual machines. Specifically, a rod-shaped cylinder 70 is used as a test object, a parallel light beam is applied from a slit light source perpendicular to the axis of the cylinder 70, and a flow pattern in a plane perpendicular to the axis of the cylinder 70 is used as incense smoke. And visualized. Note that the wind tunnel experiment was performed by controlling the rotation speed of the propeller fan to 360 rpm to 600 rpm (air flow velocity = 0.25 m / s to 0.6 m / s). As a result, clear streamlines could be observed in all of the above three types of actual machines.

  FIG. 7 is a photograph showing the experimental results. When the cylinder 70 was stationary, a clear Karman vortex street could be observed as shown in FIG. On the other hand, when the cylinder 70 was rotated, a flow pattern similar to the potential flow around the rotating cylinder could be clearly observed as shown in FIG. 7B.

  As described above, according to the present invention, a vertical wind tunnel device that can be easily disassembled, assembled, and transported is provided. The vertical wind tunnel apparatus of the present invention is expected to be used in a wide range of fields including school education.

DESCRIPTION OF SYMBOLS 10 ... Vertical wind tunnel apparatus, 12 ... Air introduction part, 13 ... 1st rectification | straightening part, 14 ... Shrinkage part, 16 ... Visualization test part, 17 ... Eddy propagation prevention part, 18 ... 2nd rectification | straightening part, 20 ... Airflow generation part, 22 ... Propeller fan, 24 ... Slidac, 26 ... Pedestal, 30 ... Sample support column, 32 ... Rotation drive means, 50 ... Special case, 60 ... Light projector, 62 ... Plate, 64 ... Transparent container, 70 ... Cylinder

Claims (7)

  A vertical wind tunnel device comprising a transparent cylindrical visualization test unit installed in a vertical orientation, wherein the flow direction of the air flow in the visualization test unit is a vertically downward direction.   A vertical wind tunnel device comprising an air introduction part, a first rectification part, a contraction part, a transparent cylindrical visualization test part, a second rectification part, and an airflow generation part, -Formed by stacking and joining the parts configured to be freely joined in the vertical direction, and the visualization test part is installed vertically so that the flow direction of the airflow is vertically downward A vertical wind tunnel device.   The vertical wind tunnel device according to claim 2, wherein the parts are joined to each other without being bolted by fitting.   The vertical wind tunnel device according to claim 2 or 3, wherein the visualization test part is formed of an acrylic pipe.   The support column for fixing a test object is protrudingly provided in the internal space of the said visualization test part, This support column is comprised so that rotation is possible, Any one of Claims 2-4 The vertical wind tunnel device described.   The vertical wind tunnel device according to any one of claims 2 to 5, wherein the rectifying portion is formed of a honeycomb member.   The vertical wind tunnel device according to any one of claims 2 to 6, further comprising an optical system in which a cylindrical transparent container filled with water functions as a condenser lens with respect to a projector having a slit.