Abstract: How to calculate turbulent flow by solving Navier-Stokes equations on unstructured grids is investigated.The cell-center finite volume method is used to solve N-S equations.Baldwin-Barth one equation turbulence model is chosen to calculate turbulent flow which is especially suitable to unstructured meshes.The model consists of a single advection-diffusion equation with a source term.In order to solve this model equation on irregular grids,an explicit finite-volume scheme is delivered,and its time step limiting condition is obtained by analyzing stability of the scheme which possesses a source term.At the end,the numerical examples,such as turbulent flow around flat,RAE-2822 foil and multi-element foil,are given which verify the validation of the computational method.

Key words: unstructured grid, turbulence model, viscous flow, numerical computation