An implementation of the Spalart–Allmaras turbulence model in a multi-domain lattice Boltzmann method for solving turbulent airfoil flows

A methodology for solving turbulent airfoil flows based on the lattice Boltzmann method is proposed. It employs a multi-domain grid refinement approach, the cascaded collision operator, and a finite-difference implementation of the Spalart–Allmaras turbulence model. It is validated for the flow over a NACA0012 airfoil at a Reynolds number of 5×105, and over the low Reynolds S1223 and E387 airfoils, both at Re=2×105. The results for the NACA0012 airfoil, in terms of force coefficients, pressure coefficients, and velocity profiles, compare favorably with the numerical results of two other studies, both of which use the Spalart–Allmaras turbulence model. The results for the other two airfoils successfully capture the experimental lift and drag profiles reported in the literature. Overall, the proposed methodology is shown to be appropriate for solving turbulent airfoil flows, provided the grid is sufficiently refined near the walls.