JPH0416188Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a turbulence generating device that generates turbulence in fluid flowing in a wind tunnel or a water tank.

[Conventional technology]

Wind tunnels are used to simulate in the laboratory the dispersion of smoke from chimneys and tunnel exhaust stacks, and the turbulence of wind caused by skyscrapers. Also, bridges, chimneys,
Wind tunnel experiments and water tank experiments are indispensable to examine the wind resistance and flow resistance of structures exposed to wind and water flows, such as offshore structures. It is extremely difficult to reproduce this in a wind tunnel or an aquarium.

Conventional methods for generating turbulence include placing grids in the fluid and placing flags, but both methods are difficult to measure experimentally, response analysis is extremely complex and difficult to understand, and it is difficult to reproduce natural turbulence. It lacked practicality due to its insufficiency and other factors.

Therefore, as shown in FIG. 3, a device has been proposed and put into practical use that rotates a rotating plate within a flow path to generate turbulence in the flow.

This device consists of rotary plates 02 arranged horizontally in a wind tunnel outlet 01, arranged in a row perpendicular to the flow path, and the left and right ends of the rotary shafts 04 attached to a frame 06 via bearings (not shown). It is designed so that it can be rotated.

Rotation of the rotary plate 02 is performed by forward and reverse rotation of a motor 03 that meshes with a gear 05 attached to each rotary shaft 04.

[Problem that the invention attempts to solve]

In such a conventional device, fluctuating wind is generated by the swinging of the rotary plate 02, but in this case, the fluctuating wind has the same fluctuating wind speed at the same time in the direction of the rotary axis 04 of the rotary plate 02. becomes. However, natural wind does not have such a simple distribution, but usually has a three-dimensional variable wind speed distribution. In other words, if the distance between two points in space is x and the correlation coefficient of fluctuating wind speed between the two points is Rx, then in the case of natural wind, x = 0 (same point) as shown by solid line A in Figure 4.
Then, Rx=1 (perfect correlation), and as x becomes larger, Rx approaches 0 (no correlation). On the other hand, in the case of the fluctuating wind caused by the rotating plate 02, as shown by the dashed line B, even if x becomes large, only a slight attenuation is observed and Rx becomes approximately 1. According to this,
The fluctuating aerodynamic forces acting on specimens such as bridges and chimneys are
This is different from natural wind, and it is not possible to accurately reproduce actual phenomena.

[Means for solving problems]

The present invention consists of a rectangular rotating plate that is perpendicular to the flow and rotatably supported in parallel in a flow path of a wind tunnel or water tank, and a drive mechanism that rotates the rotating plate. A turbulence generating device for generating turbulence in the flow in a passage, in which the plurality of rotating plates are divided into a plurality of sections in the longitudinal direction, and each divided row is rotated by a separate drive mechanism. be.

[Effect]

In the device of the present invention, the rotary plate is divided into a plurality of parts in the longitudinal direction, and each divided row is rotated independently. Therefore, the rotating plate has a plurality of rotation angles in its length direction, and the uniform fluctuating wind as in the conventional case does not occur.

〔Example〕

Hereinafter, the present invention will be described with reference to an embodiment of the apparatus shown in FIGS. 1 and 2, and this embodiment is also an example of a wind tunnel, as in FIG. 3.

A frame 6 is attached to the air outlet 1 of the wind tunnel, and the frame 6 is divided into three sections by partition plates 6A and 6B. 2 is horizontally multiple (6 in the figure)
) Rotating plates are arranged in parallel and are divided into three parts in the longitudinal direction so as to be accommodated in each section of the frame 6, respectively. Each of these divided rotary plates 2A, 2B, 2
From both ends of C are independent rotation axes 4A, 4B,
4C protrudes and is held by a bearing (not shown) attached to the frame 6 or the partition plate 6A.

5A, 5B, 5C are gear groups (5A, 5B are not shown), consisting of one fixed to the rotation shaft and the other gear meshing between them.
Forward/reverse rotation of 3B, 3C is performed by rotating shafts 4A, 4B,
This is to be transmitted to 4C.

Now, by computer etc., motors 3A, 3
Rotate B and 3C independently in forward and reverse directions. Rotation shafts 4A, 4 via gear groups 5A, 5B, 5C
B and 4C are rotated, an example of which is shown in FIG. The waveform C indicates the rotation angle of the rotation axis 4A, the waveform D indicates the rotation angle of the rotation axis 4B, and the waveform E indicates the rotation angle of the rotation axis C. Each divided rotation plate 2A, 2B, 2C has its rotation axis 4A,
Each row is rotated by independent rotation of 4B and 4C.

Therefore, different turbulence can be generated in the flow passing between the rotating plates 2 in the longitudinal direction, that is, in the width direction of the wind tunnel outlet 1. In the above embodiment, the rotating plates 2A, 2B, and 2C are arranged horizontally in a straight line, but they may be arranged with different heights.

〔effect〕

According to the device of the present invention, it is possible to generate a fluctuating flow having a spatial distribution in a direction perpendicular to the flow in a wind tunnel, a water tank, or the like.

[Brief explanation of the drawing]

Fig. 1 is a diagram of a device showing an embodiment of the present invention, Fig. 2 is an illustration of the rotation angle of the rotation axis, Fig. 3 is a diagram of a conventional device, and Fig. 4 is the correlation between distance and wind speed. FIG. 2... Rotating plate, 3A, 3B, 3C... Motor.

Claims (1)

[Scope of utility model registration request] It consists of a rectangular rotating plate that is rotatably supported perpendicular to the flow in a wind tunnel or water tank and parallel to the flow, and a drive mechanism that rotates the rotating plate. In the turbulence generating device for generating turbulence, the plurality of rotary plates are divided into a plurality of parts in the longitudinal direction, and each divided row is rotated by a separate drive mechanism. Flow generator.