Flow around a Permeable Rectangular Plate Standing Vertically on the Flat Wall (1st Report, The case of the Permeable Square Plate)

The flow around a permeable square plate, normal to a stream, standing vertically against the flat wall on which the turbulent boundary layer was developing was investigated experimentally. The velocity profile of the wake, the vortex shedding from the permeable plate and the surface pressure distribution on both the plate and the flat wall were measured for a permeable plate with various open area ratios. The profiles of wake velocity vectors and the flow visualization by both oil-film and smoke-wire techniques clarified that the circulation region behind the permeable plate was moved downstream by the bleed flow with increasing open area ratio, and that the circulation region disappeared for a large open area ratio. The vortex shedding can be found for the permeable plate with a small open area ratio. In addition, the drag coefficient shows a significant change at an open area ratio of about 0.2.