The Comparison, Improvement And Application Of Turbulence Models

The applications of algebraic turbulence models and two-equation turbulence models in the numerical solution of averaged the Navier-Stokes equations are discussed in this article. Some improvements and developments have been done for the turbulence models. The N-S equations are discretized in space using a Galerkin finite element approach, and are integrated in time using an explicit five-stage Runge-Kutta time-stepping scheme. To ensure the numerical dissipation much smaller than the physical viscous terms, directional scaling of the artificial dissipation is achieved and proper boundary conditions are also introduced in this term. In order to advance the SST turbulence equations at the same rate as the flow equations, a point-implicit scheme is used. The convection term in turbulence equations is discretized using first-order upwinding scheme to ensure more stability in time integration and the positivity of the turbulent variables.At the end, comparison for turbulence models have been done through numerical experiments and some influences such as computational grids are discussed. A lot of numerical results are presented and compared with experiment data to validate the development of the numerical method and the improvement of the turbulence models.