SOME ASPECTS OF THE FLOW PAST A SQUARE FLAT PLATE AT HIGH ANGLE OF ATTACK.

It was observed already very early, that the force acting on a flat, square or circular plate in low-speed flow experiences an abrupt and considerable drop with increasing angle of attack at some high incidence and that this is accompanied by certain changes in the flow field on the leeward side. A square, flat, sharp-edged plate was investigated in the low-speed wind tunnel of the University of Petroleum and Minerals. Flow patterns were obtained by means of the surface oil-flow technique, smoke flow-visualizations and tufts. The vortex shedding behind the plate was studied with the aid of a stroboscope and a hot-wire.