Investigating surface micro-actuation for flow control

Recent numerical simulations have suggested a transverse forcing as an effective means of drag reduction. It is believed that transverse forcing disrupts the generation and evolution of near wall instabilities located within the viscous and buffer layers. Here we report recent progress toward an experimental investigation of this claim, and the design of an active skin surface capable of producing traveling wave motion. An experimental setup which uses a moving belt to generate a traveling wave motion is presented as a means of conducting parametric studies, thus providing a way to determine optimal parameters such as wavelength and amplitude. The active surface under investigation utilizes direct forcing of an inactive elastic substrate using a distributed array of piezoceramic elements. The general problem of producing a traveling wave in this surface is also discussed.