Drag Reduction in Turbulent Boundary Layers with Half Wave Wall Oscillations

Figure 1

Computational box as seen from the negative -direction with the growth of boundary layer illustrated. Fringe region forces the solution back to the prescribed laminar inflow thus enforcing periodic boundary condition. The lower part illustrates the spanwise velocity forcing which is applied in a part of the wall under the turbulent boundary layer. Half square waves are used in the present study as shown in the bottom figure.