JPH0564727B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wind tunnel, and particularly to a wind tunnel that is optimal for use in smoke diffusion tests and the like.

[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.
In addition, it is necessary to obtain data that can be quantitatively understood and used to determine the most effective and economical location, height, and exhaust gas emission rate of chimneys depending on 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. 3 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.
The shape of the shear 10 changes depending on weather conditions, but the shape of the shear 10 within the measurement cylinder 5 determines the diffusion situation and is extremely important in model tests.

[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 brought to a uniform speed by the contraction cylinder 4, it was necessary to reduce the wind speed near the ground to zero at an early point, and then wait for the boundary layer to develop. . 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.

[Means for solving problems]

The present invention provides an elongated body installed substantially horizontally, a dividing plate placed horizontally at one end of the body that divides the inside of the body into a plurality of upper and lower parts, and each inside of the body divided by the dividing plate. This wind tunnel is equipped with a blower that is installed on the body and sends air toward the other end of the body, and a controller that independently adjusts the amount of air blown by each blower.

[Effect]

The body of the wind tunnel of the present invention is installed horizontally, and one end thereof is divided into a plurality of upper and lower parts by a dividing plate. A blower whose air flow is adjusted by a controller is
It is installed inside each divided torso, and is designed to send air toward the other end of the torso.

Therefore, winds with different speeds can be created in the upper and lower parts of the shell.

〔Example〕

The present invention will now be described with reference to an embodiment of the apparatus shown in FIGS. 1 and 2.

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 dividing plates, which are arranged approximately horizontally at equal intervals on one end side of the body 11 (four plates in the figure).
It is attached to the wall of 1. Reference numeral 16 denotes a blower, which includes a rotating shaft 16A extending through the body 11 between the dividing plates 14, an elongated blade 16B attached to the rotating shaft 16A, a recess 16C formed by the dividing plate 14, and , and a motor (not shown).

Incidentally, variable speed motors are used, and the number of rotations of the rotating shaft 16A can be freely set by a controller (not shown). In addition, 17 is a guide plate between the dividing plates 14 (or between the dividing plates 1
4 and the trunk wall) as necessary.

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. 3, 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.

The amount of air blown by five air blowers 16 arranged above and below is increased as the air blowers are placed higher. When the rotational speed of the motor (not shown) is increased by a controller, the rotational speed of the rotating shaft 16A and the blades 16B is also increased, and the amount of air blown is proportional to the rotational speed. At the ends of the dividing plate 14, winds of different wind speeds come into contact with each other,
While flowing towards the center of the barrel 11, a shear shape as shown at 18 can be obtained.

Further, in a test that requires a shear shape in which the wind velocity is slow in the middle part of the body 11, the amount of air blown by the blower 16 in the middle part may be reduced.

In the above embodiment, the dividing plates 14 are arranged at equal intervals, but the intervals may be arbitrarily changed as necessary.

〔effect〕

In the wind tunnel of the present invention, the wind speed inside the shell can be set freely in the vertical direction, 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 an enlarged view of the main part thereof, and FIG. 3 is a diagram of a conventional wind tunnel. 11...Body, 14...Dividing plate, 16...Blower.

Claims (1)

[Claims] 1. A long trunk installed approximately horizontally, a dividing plate placed horizontally at one end of the cylinder and dividing the inside of the cylinder into a plurality of upper and lower parts, and each of the cylinders divided by the dividing plate equipped with the above-mentioned A wind tunnel characterized by comprising 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 blower.