Effects of Boundary Layer Suction on a Laminar Separation Bubble on a HLFC Wing

Abstract

Experimental and numerical studies were conducted on a hybrid laminar flow control wing utilizing wall suction to investigate the impact of the suction boundary layer on the laminar separation bubble at Reynolds number �� (10^5). High-fidelity Large Eddy Simulations were performed to simulate the flow around the wing with and without wall suction, and wind-tunnel experiments were carried out in a closed circuit wind-tunnel, utilizing Hot Wire Anemometry (HWA) to measure the boundary layer profiles. A good agreement was observed in the boundary layer velocity and pressure distributions for two different freestream velocities corresponding to Reynolds numbers of 380,000 and 760,000. The results showed that boundary layer suction delays the onset of the laminar separation bubble. As the suction coefficient increases, the bubble moves towards the trailing edge of the airfoil until it reaches 95% chord at the reattachment point