The study of the characteristics and structures of turbulent boundary layer flow using direct numerical simulation

Frictional drag is a major parameter that influences the efficiency of many engineering applications involving a relative motion between a solid surface and a turbulent fluid like the flow of air over an aircraft, water over a ship hull and flow of oil through pipelines. A thin layer of fluid near the bounding surface is called the boundary layer. The turbulence activity in the boundary layer is responsible for the majority of the frictional drag. An in-depth understanding of the mechanism of skin friction generation in wall-bounded turbulent flows is essential for the development of better flow control techniques and drag reduction devices. In this study, direct numerical simulations of three turbulent boundary layer cases with different streamwise pressure gradients are considered to investigate the various factors and coherent structures that influence the skin friction.