Numerical study of passive forcing on the secondary instability of a laminar planar free shear layer

Direct numerical simulations were performed of a free shear layer developing downstream from a no-slip splitter plate. The simulation results show that three-dimensional streaky perturbations developing in the boundary layer on the high-speed side of the splitter plate are convected downstream from the trailing edge and influence the development of three-dimensional perturbations in the planar free shear layer. Simulations are performed in which a spanwise-wavy shape is introduced to the trailing edge of the splitter plate to influence the downstream development of the free shear layer. Introduction of the spanwise-waviness to the trailing edge results in significantly earlier small-scale breakdown of the free shear layer.