This paper describes the flow past two perforated plates placed on a ground plane. The experiment was carried out in the 20cm×20 cm circuit-type wind-tunnel having the working section of 2 m length at Reynolds number of 1.32×104. The time mean velocity in the flow field around the two perforated plates was measured by use of laser Doppler velocimeter. The streamline and recircuration region around the two plates were obtained. The results were discussed for the various values of porosity and

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... cing between the two plates in comparison with the result for the case of a single perforated plate. The flow pattern and vortices were observed by flow-visualization. Consequently, it was found that the windbreak is effective for the perforated plate of porosity ratio λ=0.238 for L/H=12.