MULTIGRID SOLUTION OF COMPRESSIBLE TURBULENT-FLOW ON UNSTRUCTURED MESHES USING A 2-EQUATION MODEL

The steady state solution of the system of equations consisting of the full Navier-Stokes equations and two turbulence equations has been ob tained using a multigrid strategy on unstructured meshes. The flow equ ations and turbulence equations are solved in a loosely coupled manner . The flow equations are advanced in time using a multistage Runge-Kut ta time-stepping scheme with a stability-bound local time step, while the turbulence equations are advanced in a point-implicit scheme with a time step which guarantees stability and positivity. Low-Reynolds-nu mber modifications to the original two-equation model are incorporated in a manner which results in well-behaved equations for arbitrarily s mall wall distances. A variety of aerodynamic flows are solved, initia lizing all quantitities with uniform freestream values. Rapid and unif orm convergence rates for the flow and turbulence equations are observ ed.