Turbulent Boundary Layer Flow over a Flat Plate Vibrating with Transverse Standing Waves

An attempt is made to show theoretically that the drag caused by a turbulent boundary layer on a smooth flat plate vibrating with low amplitude transverse standing waves is the same as for a non-vibrating plate provided the wave celerity of the component traveling waves is greater than about 3.5 times the free stream velocity. Experiments conducted in a water tunnel with a rectangular Cross-section having one vibrating wall showed no measurable change in boundary layer velocities, as compared to non-vibrating conditions, for frequencies ranging from 15 to 122 cps and free stream velocities ranging from 2.4 to 15 fps. The lowest wave celerity to free stream velocity ratio tested was 2.54.