Application of a wall function to simulate turbulent flows in foil bearings at high rotational speeds

For turbulent simulations in hydrodynamic applications, a fine mesh close to wall boundaries is required to correctly predict the friction and heat fluxes. This results in a remarkable increase of computational cost due to the high aspect ratio cells and reduced allowable time step. To reduce the computational cost, a compressible wall function is introduced and validated with the representative flows. Moreover, high aspect ratio cells lead to simulation instabilities. These spurious oscillations are smoothed through the addition of a fourth-order artificial dissipation term. To verify that the solution accuracy is not affected, the method of manufactured solution is applied. These two additions result in a fast and stable solver for turbulent simulations of foil thrust bearings.