Investigation on actuator arrays for active wave control on a 2D airfoil

Abstract

This paper describes different actuators for delaying laminar-turbulent transition by active boundary layer control. Since transition on an unswept 2D wing is initiated by Tollmien-Schlichting instabilities, friction drag can be reduced by attenuation of these waves. The performed experiments are based on earlier investigation with single spanwise as well as streamwise cascaded actuation. As a consequent step and essential part of this work actuator arrays consisting of slots and oscillating surface membranes for spatially distributed actuation were developed. A single spanwise sensor actuator system was applied to a glider, because flow instabilities of free atmosphere can not be simulated in wind tunnel experiments. In this way the method of active TS wave attenuation could successfully be verified under actual flight conditions. © 2010 Springer-Verlag Berlin Heidelberg.