Abstract

Complex turbulent flows in engineering applications or in the environment are becoming more complex with the effects of several external factors (pressure gradients, roughness …). An important category of complex turbulent wall flows is adverse pressure gradient turbulent boundary layer flows. The study of these flows raises several questions. What are the similarity or simplified laws that describe these flows? Are the self-sustaining and transport mechanisms of turbulence the same as the known ones in canonical wall flows? Answering these questions is essential for the improvement of turbulence models and for the design of more effective methods of flow control in order to improve the aerodynamic performance of devices. In this study, non-equilibrium adverse pressure gradient turbulent boundary layer flows and the mechanism and interaction of turbulence structures occurring in these flows will be investigated by direct numerical simulations.