Evaluation of numerical wall functions on the axisymmetric impinging jet using OpenFOAM

The present wall functions solve full momentum and energy equations on a sub-grid, using face fluxes of advection and diffusion to transfer the solution to and from the sub-grid. The evaluation was carried out on an axisymmetric impinging jet using the turbulence model of Launder and Sharma (1974) with the correction of Yap (1987).Compared to standard LRN calculations, the results show perfect agreement to less than one-sixth of the computational cost. However, the reason for the speed-up is shown to come mainly from the meshing strategy, and none of the evaluated wall functions add much additional value.