Numerical application of k-ɛ turbulence model to the flow over a backward-facing step

A model that uses the operator splitting technique based on Eulerian-Lagrangian method and embeds the k-ɛ turbulence mode is developed. The model is used to simulate a two dimensional flow over a backward-facing step with triangular mesh discrete flow field. The convection operator is solved with the characteristic method and the diffusion operator and pressure-Poisson equation are solved by finite element method. The results from the example showed that numerical results are well agreed with the experimental data, and that the method can be adapted to simulate complex turbulent flow with strong non-linear convection. The treatment of boundary conditions is also studied in the paper.