Numerical investigation of drag reduction using moving surface boundary layer control (MSBC) on NACA 0012 airfoil

Flow separation occurs due to boundary layer formation over the airfoil surface. It has significant effects on aerial application. The wake formation, due to the separation of boundary layer, attenuates the pressure differential on airfoil-especially at high angle of attack. The application of momentum injection via moving surface in the flow field energizes the flow field and improves the adverse pressure gradient and attenuates the wake formation. This study focuses on the drag reduction by improving adverse pressure gradient and narrowing the wake zone of 2D NACA 0012 by moving surface through Numerical Analysis (CFD). Selection of the speed of moving surface for investigation purpose and to get aerodynamic advantage. So one slot with a width of 5% of the chord length is placed at suction surface for single moving surface starting from 0.05c to 0.1c and for double moving surface two slots of 5% of the chord length are placed, one at suction surface starting from 0.05c to 0.1c and the other at pressure side from 0.05c to 0.1c. Momentum injection into the flow field narrows the wake zone in the vicinity of trailing edge of the airfoil. By momentum injection through single moving surface, when the surface speed ratio (u/U) is 1, it is possible to reduce the drag coefficient on an average by 13% and for double moving surface it is possible to reduce the drag coefficient on an average by 14.22%.