Numerical simulation of turbulence in the presence of shear

Numerical computations of three-dimensional time-dependent turbulent flows are now feasible for three main reasons. The state of the art of numerical methods for solving the nonlinear Navier-Stokes equations of turbulent flow modeling for numerical simulations, and of fast computer hardware have all made three-dimensional simulation a reality. The numerical calculations of the large eddy structure of turbulent flows, by use of the averaged Navier-Stokes equations, where averages are taken over spatial regions small compared to the size of the computational grid. The subgrid components of motion are modeled by a local eddy-viscosity model. The numerical simulation of the model equations of turbulence proves to be a convenient way for extracting useful information on the physics of a variety of turbulent flows. The numerical results extend existing experimental data considerably.