The Direct Numerical Simulation of Three-Dimensional Spatially-Developing Free Shear Flow

Direct numerical simulation of three–dimensional incompressible plane free shear flow is performed. Mass and momentum equations are solved in a domain which is finite in the streamwise direction (x), doubly infinite in the cross–stream direction (y) and homogeneous in the spanwise direction (z). In the x direction a high-order compact finite differencing scheme is used. In the y and z directions, a mapped spectral method and a Fourier spectral method are used, respectively. The numerical results for several known cases are computed and compared with their (analytical or experimental) solutions. This is performed to establish and verify the accuracy of the numerical code. Results indicate that the accuracy of the direct numerical simulation is excellent for the class of free shear flow in general and plane wake flow in particular. The code can be used as a perfect tool to investigate turbulence for the class of free shear flow problems.