An Overview of Recent DLR Contributions on Active Flow-Separation Control Studies for High-Lift Configurations

This is an overview of flow control experiments and simulations for flow separation control on high-lift configurations performed over the last seven years at the German Aerospace Center within national and European projects. Emphasis is placed on the low speed atmospheric and cryogenic experimental setups using the DLR F15 high-lift airfoil and on the numerical verification and validation of the Reynolds Averaged Navier Stokes (RANS) solver TAU for active flow control (AFC) simulations. The wind tunnel studies concern leading edge boundary layer control and flap separation control, both by means of pulsed blowing. The computational effort is mostly dedicated to the most promising technology out of the two concepts, namely the pulsed blowing through slots on the trailing edge flap. Experimental examples of successful flow control for enhancement of lift are given for moderate and high Reynolds numbers to prove the feasibility of the technology for implementation on real aircraft. The computational process chain is validated with wind tunnel measurements, but also applied for an optimization of the trailing edge flap shape for separation control.