Preconditioning discontinuous Galerkin method for low Mach number flows

The finite volume preconditioning method is applied to the discontinuous Galerkin method for three-dimensional viscid low Mach number flows. The traveling wave case is used to verify that the preconditioning discontinuous Galerkin method is suitable for viscid low Mach number flows and that the method retains the original discrete accuracy of the discontinuous Galerkin method. The results for four classical cases (lid driven incompressible flow, a Blasius boundary layer, a backward facing step with turbulent flow and natural convection in a square enclosure) validate the applicability of the preconditioning discontinuous Galerkin method and the reliability of the program. The flow around a NACA0012 airfoil for three different Mach numbers show that the convergence speed is independent of the Mach number. ©, 2015, Press of Tsinghua University. All right reserved.