Unsteady turbulent flow simulation using lattice boltzmann method with near-wall modeling

A novel wall-modeled large-eddy simulation (WMLES) based on lattice Boltzmann method (LBM) is presented. Near-wall modeling for a turbulent boundary layer is essential in order to calculate the high Reynolds number wall-bounded turbulent flow that appears in an actual engineering field. WMLES based on the reconstruction of distribution functions is further developed to handle the objects on a non-body-fitted Cartesian grid. In order to overcome the drawback of the existing model, Image-Point (IP) is introduced to the model. Furthermore, the strategy to determine the turbulent eddy viscosity profile near the wall is proposed by considering the shear-stress balance in an inner layer. For the validation of the proposed model, numerical simulations of a turbulent channel flow are conducted and the calculation results are compared with the DNS results or the semi-analytical profile in terms of the streamwise velocity and the resolved Reynolds shear stress profiles. The proposed model is observed to be both robust and accurate, yielding the very satisfactory results regardless of the angle between the Cartesian grid line and the wall.