プラズマアクチュエータ誘起噴流を用いたGurney Flap効果

Abstract

Lift and drag variations by plasma actuators have been investigated under flow at low Reynolds numbers ranging from 1.7×104 to 6.6×104. Wall-normal-jet type and counter-jet type plasma actuators are attached on the pressure surface near the trailing edge of NACA0015 airfoil, and jets are induced from x/c = 0.9 toward wall normal and opposite directions against the main flow. Appreciable variations of lift and drag coefficients are not observed in the case of flow control by the wall-normal-jet type plasma actuator. On the other hand, it is confirmed that the counter-jet type plasma actuator is effective for improving aerodynamic characteristics. As the most effective case at Re = 3.3 ×104, lift coefficient is enlarged up to 30% under lower angles of attack α ≤ 8°, and velocity distributions analyzed by PIV shows that flow near the trailing edge accelerates to y-axis negative direction. Effects of lift enhancement by counter-jet type plasma actuator tend to fall off with increasing Re. Lift and drag coefficients of NACA0015 with conventional Gurney flap (h/c = 0.03) are also compared with that by the counter-jet type plasma actuator. It is found that the lift enhancement by Gurney flap is effective over a wide range of angle of α, but counter-jet type plasma actuator suppresses enlargements of drag coefficient in high α.