Abstract
Two acoustic surface waves (with frequencies around 1MHz) with slightly different frequencies that are propagating in opposite directions and interfering on a solid wall are used for controlling liquid film flow on the solid wall. The liquid film flow are visualized by doped paint pigment and monitored by a digital video camera. When the frequency difference are small, a flow is induced by the interfering acoustic waves. The flow velocity first increases with increasing frequency difference when the frequency difference is less than 1Hz, and then, the velocity decreases as the frequency difference are larger than 1Hz.
