Actuating Traveling Surface Waves in Elastic Media

Recent developments from the field of fluid dynamics suggest that it is possible to significantly alter the flow characteristics using very small deformations of the boundary wall. In particular, it is believed that transverse forcing disrupts the generation and evolution of near wall instabilities located within the viscous and buffer layers. A physical realization of this flow control method requires active surfaces capable of producing prescribed surface motion. The condition of specifying surface motion falls under the dynamical control theory of program constraints, in which motion is only partly specified. For an elastic material, the basic problem is to find the material properties and external forcing required to produce the specified motion. We discuss the basic nature of this problem and present approaches to its solution.