Numerical analysis of the effects of tangential transpiration on the boundary layer characteristics

In the present study, the characteristics of the turbulent boundary layer developing on a porous wall with various angles of injection and suction are analyzed numerically with the proper boundary conditions. The finite difference method based on a control volume approach is used for solving the time averaged Navier-Stokes equations for incompressible flow in conjunction with the standard k-epsilon turbulence model equations. The wall functions of the viscous and turbulent sub-layers are modified to allow for the effect of the angle of injection and suction through the porous wall. A non-uniform staggered grid arrangement is used The parameters studied include the velocity (V-w) and the angle (alpha) of the injection and suction. The present numerical results of the normal injection and suction are compared with the known experimental data and a good agreement is obtained The numerical results also indicate that the characteristics of the turbulent boundary layer such as local friction coefficient, boundary layer thickness and shape factor are substantially influenced by the velocity and the angle of injection and suction.