Water tunnel visualization around the perforated cube : 1st report, flow visualization in a center plane

Flow field around the perforated cude placed on the flat plate has been investigated using a water tunnel experimentally. Observation around a cube of various open area ratios has been made by the dye method and the hydrogen bubble method. The pattern are photographed from lateral side, in order to make clear the mechanism of the change of patterns with varying the open area ratio and the Reynolds number. With increasing the open area ratio, the hydraulic shadow is narrow and an adverse pressure gradient upstream the model is weak. As the Reynolds number is incrcased, the strength and the frequency of tho vortex shedding are large.