Numerical Study on Drag Reduction by Micro-Blowing/Suction Compounding Flow Control on Supercritical Airfoil

Micro-Suction technique(MST) is proposed by the development of micro-blowing technique(MBT). Current experiments and numerical studies are mostly focusing on MBT, micro-suction flow control in turbulent boundary layer remains unstudied. Thus, based on 2D-RAE2822 supercritical airfoil, numerical research on MST and MB/ST compounding flow control have been carried out. And Micro-Porous Wall Model(MPWM) is used to represent the real effects that the blowing and suction of the micro-porous wall has on the surface flow.The numerical results of micro-suction indicate that micro-suction control is capable of inducing a lower pressure zone in front of the micro-porous zone, and a higher pressure zone in the rear end. Given that micro-porous zone is placed on the particular section of airfoil, where the pressure drag direction is backward parallel to free-stream direction, the reduction of the pressure induced by micro-suction control can result in the decrease of pressure drag. Finally, combining the previous study on the MBT, a compounding configuration of micro-blowing/suction flow control on RAE2822 airfoil is proposed. The compounding configuration can take the advantage of both micro-blowing and micro-suction, over 20% increase of the lift and up to 15% decrease of the drag can be realized. Therefore, the compounding flowing control of micro-blowing/suction shows a great potential for the flow control on aircraft.