JPH0564728B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wind tunnel, which is most suitable for use in a smoke diffusion test, etc.

[Conventional technology]

In order to prevent air pollution caused by exhaust gases emitted from power plants, chemical factories, etc., it is necessary to qualitatively analyze the diffusion status of these polluted exhaust gases in the atmosphere and on the ground surface.
In addition, it is necessary to obtain data that can be quantitatively understood and used to determine the most effective and economical chimney installation location, height, exhaust gas emission rate, etc. according to location conditions, scale, etc.

Methods for obtaining such data include calculation methods, on-site testing methods, and model testing methods.

As a calculation method, Sutton
Theoretical formula, Sakagami's formula, and the British Met Office's empirical formula have been published, but none of them take into account the influence of topography. In addition, there have recently been cases in which the influence of topography on these equations has been determined by numerical analysis using a computer, but in either case verification by experiment is required.

The field test method cannot be tested until after the actual chimney has been constructed, and conducting tests in a wide area with complex topography would be extremely costly and labor intensive. Moreover, it is difficult to freely select the height of the chimney, wind direction, etc., and data can only be obtained from one location.

Tests using models include discharging gas from a chimney model and observing the gas diffusion situation with the naked eye to understand qualitatively, or quantitatively measuring the concentration by suctioning the gas. I'm going.

FIG. 4 shows an overview of this type of experiment using a conventional wind tunnel.

The wind 2 generated by the blower 1 is once diffused by the diffusion cylinder 3 and then condensed by the contraction cylinder 4, and is discharged into the measurement cylinder 5 as a parallel flow. Inside the measurement cylinder 5, so-called topographical models such as a roughness 6 for controlling ground friction, a chimney model 7 for discharging tracer gas, a building model 8, and a ground surface model 9 are arranged.

Although details are omitted, the diffusion of the tracer gas is determined by applying a color-changing reagent to the surface of the ground model 9, or by sucking the gas and determining its concentration.

In tests carried out in this way, the wind acting on the terrain model must be reproduced in the same way as the natural wind. The wind speed of natural wind is almost zero at the ground due to ground friction, slightly higher at higher places, and faster at higher places. This wind speed distribution in the vertical direction is called shear, and is shown at 10 in the wind tunnel.
Although the shape of this shear changes depending on weather conditions, the shape of the shear 10 determines the diffusion situation within the measurement cylinder 5, and is extremely important in model tests.

Further, depending on the topography upwind of a chimney or the like, the shape of the horizontal shear may not be uniform.

[Problem that the invention seeks to solve]

Conventionally, the shape of the shear 10 in the wind tunnel has been controlled only by roughness 6. In other words, in order to give the same shear shape as natural wind to the wind that has been made uniform in velocity by the contraction cylinder 4, it was necessary to reduce the wind velocity near the ground to zero at an early point, and then wait for the development of the boundary layer. . Therefore, it is necessary to make the measuring cylinder 5 longer.

In addition, only the shear shape conforming to the so-called "power law" in which the upward wind is fast could be obtained.

Furthermore, cases in which a non-uniform shear shape in the horizontal direction must be obtained have rarely been reproduced.

[Means for solving problems]

The present invention provides a long torso installed substantially horizontally, a dividing plate placed horizontally and vertically at one end of the torso to divide the interior of the torso into a plurality of upper, lower, left, and right parts, and each part divided by the dividing plate. This wind tunnel is equipped with a blower that is installed inside the shell and sends air toward the other end of the shell, and a controller that independently adjusts the amount of air blown by each of the blowers.

[Effect]

The wind tunnel body of the present invention is installed horizontally, and one end thereof is divided into a plurality of upper, lower, left, and right sections by dividing plates. A blower whose air flow rate is adjusted by a controller is installed in each divided shell, and is configured to send air toward the other end of the shell.

Therefore, it is possible to create wind with different speeds in the upper, lower, right and left directions within the shell.

〔Example〕

Hereinafter, the present invention will be explained with reference to an embodiment of the apparatus shown in FIGS. 1 to 3.

Reference numeral 11 denotes a long body installed substantially horizontally, and a bell mouth 12 for suction is connected to one end (left end in the figure) and a duct 13 with an enlarged diameter for discharge is connected to the other end. Reference numeral 14 denotes a horizontal dividing plate, and numeral 15 denotes a vertical dividing plate, which are arranged in a grid pattern at one end of the body 11 and attached to the wall. Reference numeral 16 denotes a blower, which is arranged in each section formed by the dividing plates 14 and 15.

It should be noted that the motors of the blower 16 are variable speed motors, and the rotation speed can be freely set by a controller (not shown). Furthermore, anemometers 17 are placed in front of the blowers 16, and the blowers 16 are controlled via the controller 18 so that the wind speed reaches a specified speed.

Now, tests are conducted in the wind tunnel constructed in this manner in the same way as in the past. That is, similar to FIG. 4, so-called topographical models such as a chimney model 7, a building model 8, and a ground surface model 9 are placed inside the shell 11, and a test is performed by discharging tracer gas.

By changing the rotational speed of each blower 16 in the vertical direction, the wind 2 acting on the model differs in the vertical direction, so the rotational speed of the blower 16 is adjusted so as to obtain the shear 10 to be reproduced. Similarly, non-uniform shear can be reproduced by adjusting the rotational speed of each of the horizontally adjacent blowers 16 and changing the rotational speed of each of the same blowers 16 in the horizontal direction as well.

That is, if "non-uniform shear" which is the local weather condition to be reproduced is given, the wind speed that each blower 16 should generate in the vertical direction and in the horizontal direction is set (this is called the set wind speed). As a result, the pressure distribution inside the wind tunnel measurement barrel 11 becomes non-uniform. Even if the number of rotations of the blower 16 is the same, the speed of the generated wind differs. For this reason, in order to achieve the "set wind speed",
The wind speed is detected by an anemometer 17, and a controller 18 controls the motor to increase or decrease the rotation speed of the blower 16 so that the difference from the set wind speed disappears.

〔effect〕

In the wind tunnel of the present invention, the wind speed inside the shell can be freely set in the vertical and horizontal directions, so it is extremely effective for tests such as diffusion tests that require shear adjustment.

[Brief explanation of the drawing]

Fig. 1 is a diagram of a wind tunnel showing an embodiment of the present invention, Fig. 2 is a cross-sectional view of Fig. 1, Fig. 3 is an enlarged view of the main part of Fig. 1, and Fig. 4 is a diagram of a conventional wind tunnel. It is. 11...Body, 14...Horizontal dividing plate, 15...Vertical dividing plate, 16...Blower, 18...Controller.

Claims (1)

[Claims] 1. A long trunk installed approximately horizontally, a dividing plate placed horizontally and vertically at one end of the cylinder and dividing the inside of the cylinder into multiple parts, top, bottom, left and right, and each part divided by the dividing plate. A wind tunnel characterized in that it is equipped with a blower that sends air toward the other end of the body, and a controller that independently adjusts the amount of air blown by each of the blowers.