Wall boundary conditions and mesh dependency of the solution for the calculations of turbulent flows on unstructured meshes

The specification and numerical implementation of boundary conditions on a wall in the calculations of turbulent flows on unstructured meshes are considered. Advantages and shortcomings of wall function approach and its features of implementation for different turbulence models are discussed. The way of implementation of weak boundary conditions on the wall for the discretization of Reynolds-averaged Navier-Stokes equations with the help of finite volume method is proposed. The possibilities of the approach developed are demonstrated by the example of the solution of some model problems of gas dynamics. The influence of near-wall mesh spacing on calculation accuracy is studied and the solution mesh dependency is compared for the wall functions and weak boundary conditions.