Computational Analysis on Porosity Effect on Aerodynamic Characteristic of Supercritical Airfoil

For supercritical flow over the surface airfoil, the supersonic zone may be terminated by a strong normal shock. The porous surface with cavity is a passive shock wave/boundary layer control to reduce the wave drag. The effect of porous surface on the aerodynamic characteristics and flow characteristics is investigated by solving the NS equation. The effects of the porosity parameters are also analyzed in Ma=0.8. The results show that to compare with the solid airfoil, the drag coefficient of the porous airfoil decreases about 0.0030 when the angle of attack is in the range from 0° to 4°. There is an additional drag about 0.0012 in the cavity which makes the control effects decrease. And the porous control would bring on lift coefficient decrease. With the porous number decreasing, the lift control loss decreases and the general performance of the passive control could be improved.