Tollmien--Schlichting wave damping by a streamwise oscillating Lorentz force

T. Albrecht¹ - H. Metzkes¹ - R. Grundmann¹ - G. Mutschke² - G. Gerbeth²

¹ Institute for Aerospace Engineering, Technische Universität Dresden, D-01062 Dresden, Germany
² MHD Department, Institute of Safety Research, Forschungszentrum Dresden-Rossendorf, P.O. Box 51 01 19, D-01314 Dresden, Germany

Abstract
The authors present 2D and 3D Direct Numerical Simulations of Tollmien--Schlichting (TS) wave superposition in a flat plate boundary layer, where the initial TS wave is intended to be canceled out by a second wave of opposite phase. Considering low electrically conductive fluids like seawater, an oscillating Lorentz force is used to generate the counter-phased wave. Although the force, hence, the counter-phased wave, are inhomogeneous in spanwise direction, the remaining wave amplitude is reduced by more than 90\% compared to the uncontrolled case. The penetration depth of the force and actuator length are optimized, however, efficiency of this actuation is still found to be low. Tables 1, Figs 11, Refs 41.