This paper describes effects of configuration of louvers and holes of plates on aerodynamic noise level. The aerodynamic noise mostly affects the environment and it is very important for our healthful life to reduce this kind of noise. The aerodynamic noise consists of wind noises generated from the pantograph and the louvers. In this study, the wind noise of louvers is measured and evaluated experimentally by using a low noise wind tunnel. As a result, the following conclusions were obtained that (1) Noise reduction of about 4 dB is achieved by using parallel square frame with 45deg., (2) Noise reduction of about IdB is achieved by doubling the number of fin, (3) Making the radius of the frame of the louver large is effective on the noise reduction, although the effect is small, and (4) In perforated plate, the hole area to total area is getting small, the noise level becomes small.
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