Large Scale Structures of Turbulent Shear Flow via DNS

A direct numerical simulation (DNS) of turbulent channel flow has been carried out to understand the effects of Reynolds number. In this study, the Reynolds number for channel flow based on a friction velocity and channel half width was set to be constant; Re τ = 1100. The number of computational grids used in this study was 1024 x 1024 x 768 in the x-, y- and z -directions, respectively. The turbulent quantities such as the mean flow, turbulent stresses and the turbulent statistics were obtained via present DNS. Large scale turbulence structures visualized by paralleled AVS/Express appear in whole region. The structures are merged by small scales structures.