Computational study of incompressible turbulent flows with method of characteristics

The current study presents numerical investigation of incompressible turbulent flow. Momentum and continuity equations are coupled by the Artificial Compressibility Method (ACM). The one-equation Spalart-Allmaras turbulence model along with RANS (Reynolds Averaged Navier-Stokes) equations is used to calculate Reynolds stresses in 2-D problems. For convective fluxes a characteristic-based (CB) finite-volume solution has been developed. Also, a revised Jameson averaging (AVR) method was implemented. In comparison, the proposed CB upwind scheme, demonstrated very accurate results, high stability and faster convergence. For time discretization, the fifth-order Runge-Kutta scheme is used. As the convergence acceleration techniques, the local time stepping and implicit residual smoothing were applied. Considering flow behavior, suitable boundary conditions have been implemented. Cross flow around a horizontal circular cylinder at high Reynolds numbers has been studied as a benchmark. The results obtained using the new proposed scheme, are in good agreement with the standard available solutions in the literature.