High Reynolds number immersed boundary method for turbulent flows

In this talk, we focus on the immersed boundary method with the application to high Reynolds number wall-bounded turbulent flows. The immersed boundary method is a great tool to simulate flows over complex geometries on simple Cartesian grid. But the isotropic grid refinement of the Cartesian grid limits its use at high Reynolds number, due to the unaffordable grid numbers to resolve the very thin turbulence boundary layer. The coupling of turbulence wall models and immersed boundaries is a very promising path to overwhelm the grid limitation. However, spurious oscillations have been frequently observed with respect to the wall surface quantities, especially for the surface pressure and the skin friction. These unphysical oscillations have a significant impact on the estimation of drag and lift forces. Therefore, we will present new near wall treatments for reducing these spurious oscillations. Additionally, developments on the explicit wall models and the dynamic hybrid RANS-LES technologies constrained by the Reynolds stress will be presented along with the immersed boundary technique. A wide range of benchmark flows are performed to validate the proposed models and discussions will be finally given.