EXPERIMENTS ON CYLINDER WAKE STABILIZATION IN AN ELECTROLYTE SOLUTIONBY MEANS OF ELECTROMAGNETIC FORCES LOCALIZED ON THE CYLINDER SURFACE

Electromagnetic body forces, i.e. Lorentz forces, have been used to mo dify the boundary layer around a circular cylinder in cross low. Depen ding on the polarity of the applied electric field different effects o n the flow can be obtained. Lorentz forces directed with the mean flow are able to prevent the boundary layer from separation. Therefore How separation as well as the von Karman vortex trail can be suppressed. When the momentum gain produced by the Lorentz forces in the boundary layer is high enough, thrust is produced, which results in a jet flow originated ft-om the cylinder's backside. If the Lorentz forces are di rected opposite to the mean flow, the separation points are shifted to wards the Rent stagnation point, the recirculation region broadens and the von Karman vortex trail is modified. The described technique give s a variety of opportunities to control the flow around the cylinder a nd the flow structure of the cylinder wake. Results from flow visualiz ations and numerical calculations are presented. (C) 1998 Elsevier Sci ence Inc. All rights reserved.