Laminar boundary layers in oscillatory flow along an infinite flat plate with variable suction

The two-dimensional incompressible fluid flow problem along an infinite flat plate with no heat transfer between the fluid and the plate is discussed when the suction velocity normal to the plate, as well as the external flow velocity, varies periodically with time. Expressions for the velocity and temperature fields in the boundary layer have been obtained in a non-dimensional form. It has been found that the effect of increasing the suction velocity fluctuations is that the amplitude of the skin-friction fluctuations is increased while the phase is decreased and it may be negative for very small values of the frequency. Also the plate temperature decreases with increasing the suction velocity fluctuations for small values of the frequency while there is no effect for very large frequencies.