Large eddy simulation (2D) using diffusion-velocity method and vortex-in-cell

摘要

A large eddy Simulation based on the diffusion-velocity method and the discrete vortex method is presented. The vorticity-based and eddy viscosity type subgrid scale model simulating the enstrophy transfer between the large and small scale appears as a convective term in the diffusion-velocity formulation. The methodology has been tested on a spatially growing mixing layer using the two-dimensional vortex-in-cell method and the Smagorinsky subgrid scale model. The effects on the vorticity contours, momemtum thickness, mean streamwise velocity profiles, root-mean-square velocity and vorticity fluctuations and negative cross-stream correlation are discussed. Comparison is made with experiment and numerical work where diffusion is simulated using random walk.