Blowing and suction effect on drag and lift coefficients for viscous incompressible flows over hydrofoils by power-law preconditioning method

Effect of boundary layer and its local separation on lift and drag coefficients، especially in the analysis of hydrodynamic behavior of hydrofoils is considered as an interesting subject for fluid mechanics researchers. Boundary layer control methods to increase the lift coefficient and reduce the drag coefficient، are very common. Aerodynamic study of flows at low Reynolds to special applications such as micro unmanned underwater vehicles، underwater robots and explorers are interested. For this reason in this study، the effect of fluid blowing and suction through upper surface of hydrofoils on flow control، lift and drag coefficients for flow under Re =500 and Re=2000 are investigated. Jameson’s finite volume method and power-law preconditioning method for analyzing viscous incompressible flows are presented. To control the boundary layer a jet with a width of 2. 5% of chord length is placed on hydrofoil’s upper surface and results for different blowing (suction) parameters are introduced. Results show that، blowing far from leading edge at low blowing angel and perpendicular suction far from leading edge increase the lift coefficient. Also blowing with law velocity ratio and suction with large velocity ratio، has the better impact on increasing lift coefficient.