Numerical modeling of flow control on a symmetric aerofoil via a porous, compliant coating

A passive actuation technique, that entails covering the suction side of an aerofoil with a poro-elastic carpet, is presented. Numerical modeling of the coupled fluid-structure interaction problem is performed for a low Reynolds number regime, characteristic of micro aerial vehicles. The immersed boundary technique is employed, which offers the advantage of using Cartesian grids for complex geometries. By suitably selecting the characteristics of the carpet, to synchronise characteristic time scales of the fluid and the structural systems, significant drag reduction and/or lift enhancement can be achieved, associated with modifications of the length scales of the shed vortices and a mild intensification of their intensity. A parametric analysis shows that such a coating is able to affect the topology of the flow in the proximity of the rear of the aerofoil, by adapting spontaneously to the separated flow. © 2012 American Institute of Physics.