JPH04130054U - turbulence generator - Google Patents

Abstract

(57) [Summary] [Purpose] This relates to a turbulence generating device that generates turbulence in fluid flowing in a flow path such as a wind tunnel or an aquarium, and can create a flow in the flow path with a spatial distribution close to that of a natural flow. This is how it was done. [Structure] A plurality of rows of fixed spindles 4 are arranged parallel to each other along a plane perpendicular to the flow direction in the flow path, and each of the fixed spindles 4 is swingable in order to generate turbulence in the flow path. It is characterized by comprising a plurality of supported diaphragms 3 and diaphragm rocking motors 5 attached to each of the diaphragms 3 to swing these diaphragms 3 independently. . As a result, turbulence with different fluctuation speeds is generated from each of the diaphragms 3, and a flow having a spatial distribution similar to that of a natural flow can be easily and accurately reproduced.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to a turbulence generator that generates turbulence in fluid flowing in a wind tunnel or water tank. Ru.

0002

[Conventional technology]

Generally, the dispersion of smoke from chimneys and tunnel stacks and wind disturbances caused by skyscrapers. Wind tunnels are used to simulate such events in the laboratory. Also, bridges, chimneys, the sea When considering the wind resistance and flow resistance of structures exposed to wind and water flow, such as offshore structures. However, wind tunnel experiments and water tank experiments are essential. However, the velocity component for each local area It is extremely difficult to reproduce complex turbulent flows with different levels in a wind tunnel or an aquarium. Traditionally, methods for generating turbulence include placing grids in the fluid, placing flags, etc. However, in both cases, experimental measurement is difficult, and response analysis is extremely complex and difficult to understand. It is impractical due to the lack of turbulent flow and the insufficient reproduction of natural turbulence. It was a good thing.

0003 Therefore, as shown in FIG. 3 (perspective view), the diaphragm 13 is swung within the flow path to cause turbulence in the flow. A device that generates this has been proposed and is already in practical use. This device is a wind tunnel blowout Vibration plates 13 arranged horizontally at the mouth 1 are arranged parallel to each other along a plane perpendicular to the flow path. At the same time, the left and right ends of the rotation shaft 14 that supports the diaphragm 13 are connected to bearing bearings (not shown). The diaphragm 13 is made swingable by being attached to the frame 12 through a ring. It is. The oscillation of the diaphragm 13 is achieved by rotating the gears 15 attached to the respective rotating shafts 14. This is done by engaging the motor 16 in the forward or reverse direction. At this time, the diaphragm 13 swings while making a pitching motion.

0004

[Problem that the idea aims to solve]

By the way, in the conventional turbulence generator described above, the vibration of the diaphragm 13 causes A fluctuating wind is generated in the wind tunnel. For the direction, the wind speed will have the same fluctuating wind speed at the same time. However, self Natural winds usually have a three-dimensional fluctuating wind speed distribution, rather than a simple distribution like this. I am a connoisseur. In other words, as shown in Figure 4, let the distance between two points in space be X, and the distance between the two points is If the correlation coefficient of fluctuating wind speed is Rx, then in the case of natural wind, the distance between two points in space is X=0 (same point), and the correlation coefficient Rx of fluctuating wind speed between those two points is Rx=1 ( perfect correlation), and as shown by the solid curve in Figure 4, the distance X between the two points is large. As get closer On the other hand, in the case of fluctuating wind caused by the diaphragm 13 of a conventional turbulence generator, Even if the distance X between two points in the The correlation coefficient Rx of the fluctuating wind between the above two points remains almost 1, although only a slight attenuation is observed. be. This means that the fluctuating aerodynamic force acting on specimens such as bridges and chimneys is different from natural wind. Therefore, conventional turbulence generators are unable to accurately reproduce the actual phenomenon. The problem was that they didn't come.

[0005] The present invention attempts to solve these problems, and is aimed at solving the problems described above. The diaphragm in the device is divided into multiple parts in the axial direction, and each part is provided so that it can swing independently. At the same time, by attaching a separate rocking drive device to each diaphragm, each By generating turbulent flow with different fluctuating wind speeds on each diaphragm, a spatial distribution close to the natural state is created. The purpose of the present invention is to provide a turbulence generating device that can generate a flow of target

[0006]

[Means to solve the problem]

In order to achieve the above-mentioned purpose, the turbulence generating device of the present invention has the following features: Multiple rows of fixed spindles arranged parallel to each other along a plane perpendicular to the A plurality of diaphragms each swingably supported by the fixed support shaft to generate a flow. and vibration plates attached to each of the diaphragms in order to make these diaphragms oscillate independently. It is characterized by being configured with a moving plate swinging motor.

[0007]

[Effect] In the above-mentioned turbulence generating device of the present invention, multiple turbulence generators are arranged parallel to each other along a plane perpendicular to the flow path. A plurality of diaphragms each swingably supported by several arrays of fixed support shafts are vibrated at the same time. A swinging motor attached to each moving plate provides independent swinging action. It will be done.

[0008] Then, each of the above diaphragms generates turbulent flow with different fluctuation speeds. As a result, an action is performed to create a flow whose spatial distribution is close to the natural state within the flow path. Also, depending on the experimental conditions, change the rocking speed etc. of each of the above diaphragms. Actions are also performed.

[0009]

【Example】

A turbulence generator as an embodiment of the present invention will be explained below with reference to the drawings. FIG. 1 is an overall perspective view, and FIG. 2 is an enlarged view of the main parts of FIG.

0010 As shown in Figures 1 and 2, in this example, in the plane perpendicular to the flow direction in the flow path A frame 2 is provided along the wind tunnel outlet 1, and the frame 2 has multiple rows of fixed support shafts 4. are arranged parallel to each other. The fixed support shaft 4 has a plurality of small diaphragms for swinging. In addition to the motor 5, multiple motors each having the same small motor 5 built-in are installed. A diaphragm 3 is swingably supported on a fixed support shaft 4.

[0011] In addition, the fixed support shaft 4 is composed of a hollow pipe-shaped member, and each small Power supply wiring for the motor 5 is provided within the fixed support shaft 4 . Furthermore, the book binding At the same time, power is supplied to each small motor 5 independently to control the oscillation width and oscillation of all the oscillating slopes 3. A control system (not shown) is also provided that integrates and controls the swing state such as speed.

0012 With the above configuration, in the turbulence generator of this embodiment, each diaphragm 3 can be operated independently. to generate turbulent flow with different fluctuating wind speeds from these diaphragms 3. fluctuations that occur in the wind tunnel and have a spatial distribution almost similar to that of the natural wind. The effect of easily and accurately reproducing the wind can be obtained.

[0013] In addition, the swing width and swing speed of the diaphragm 3 can be arbitrarily changed according to the experimental conditions to achieve various results. The advantage of realizing a variable wind environment is also obtained.

[0014]

[Effect of the idea]

As described in detail above, according to the turbulence generator of the present invention, multiple By oscillating the diaphragms that have been oscillated separately using different drive signals, the It is possible to generate turbulence in different directions in the flow that has passed through the diaphragm. , a fluctuating flow with a spatial distribution similar to a natural flow can be easily and accurately reproduced in a flow channel. Effects can be obtained.

[0015] In addition, the oscillation state of the vibrating slope can be changed arbitrarily to create various fluctuating flow environments depending on the experimental conditions. It also has the advantage of being realized.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view showing a turbulence generating device as an embodiment of the present invention.

[0016]

FIG. 2 is an enlarged view of the main part of FIG. 1;

[0017]

FIG. 3 is an overall perspective view showing a conventional turbulence generating device.

[0018]

FIG. 4 is a graph showing the correlation between the distance between two points and fluctuating wind speed.

[0019]

[Explanation of symbols]

1 Wind tunnel outlet 2 frame 3 Vibration plate 4 Fixed support shaft 5 Small motor for oscillating the diaphragm

Claims (1)

[Scope of utility model registration request] 1. A plurality of rows of fixed support shafts arranged parallel to each other along a plane perpendicular to the flow direction in the flow path, and each of the fixed support shafts is swingable in order to generate turbulence in the flow path. A turbulent flow generator characterized by comprising a plurality of supported diaphragms and a diaphragm rocking motor attached to each of the diaphragms to independently swing the diaphragms. Device.