The normal impingement of a circular air jet on a flat surface

Abstract

Measurements of velocity magnitude and direction, static pressure, and skin friction have been made in a circular turbulent jet impinging normally on a flat surface. The speed in the jet just before impingement was 135 ft/sec and its radius was about 2.5 in. The region of increased static pressure near the stagnation point is roughly hemispherical, with a radius slightly larger than that of the jet. The maximum value of skin friction occurs at a radius approximately equal to that of the jet and is about 0. 006 of the jet maximum dynamic pressure at the test Reynolds number. The virtual origin of the resulting radial wall jet is very close to the stagnation point.