Mitigating loads by means of an active slat

Abstract

An active slat on an airfoil is tested in the wind tunnel to reduce lift fluctuations caused by inflow angle fluctuations. The airfoil with an integrated slat allows to control the gap size between slat and main body. The variation of the gap size leads to different aerodynamic properties. This behavior is investigated in a comprehensive characterization of the aerodynamics for different positions of the static slat and a wide range of angles of attack. A sinusoidal inflow angle fluctuation is generated by an active grid. These fluctuations are causing lift force fluctuations at the airfoil with static slat. The slat gap size then is varied dynamically synchronous to the inflow angle fluctuations. Depending on the phase shift between slat gap size variation and inflow angle fluctuation a reduction of the lift force is observed. The slat system is found to be capable of mitigating load fluctuations caused by turbulent inflow.