Manipulation of trailing edge separation on an aerofoil using a periodic cross-flow

摘要

Experiments with an HQ-17 laminar aerofoil are described where flow separation in the recompression region of an aerofoil is reduced.A loudspeaker system is mounted inside the aerofoil.It generates an oscillating jet with a blowing and a suction phase in a spanwise slot in the aerofoil.Spanwise vortices are generated that enhance mixing processes,increasing hte lift coefficient c_L.The lift gain depends mainly on hte position of the separation line relative to the slot as well as the frequency and the amplitude of the excitation.