Investigation of Near-Wall Grid Spacing Effect in High-Order Discontinuous Galerkin RANS Computations of Turbomachinery Flows F. Bassi, L. Botti, A. Colombo, A. Ghidoni, and S. Rebay Abstract In the last decade, Discontinuous Galerkin (DG) methods have been the subject of extensive research effort because of their excellent performance in the high-order accurate discretization of advection-diffusion problems on general unstructured grids, and are nowadays finding use in several different applications. In this paper, the potential offered by a high-order accurate DG space discretization method with implicit time integration for the solution of the Reynolds-averaged Navier-Stokes equations coupled with the k-! turbulence model is investigated in the numerical simulation of the turbulent flow through the well known T106A turbine cascade. The numerical results demonstrate that, by exploiting high order accurate DG schemes, it is possible to compute accurate simulations of this flow on grids with few elements. 1 Introduction In the last two decades, CFD has been widely accepted as one of the main methods for evaluating the performance of new turbomachinery designs. Industrial CFD applications range from classical single- and multi-blade row simulations in steady and unsteady mode, to cavity flows, heat transfer and combustion chamber simulations. The accurate prediction of these flows requires a complete set of F. Bassi  L. Botti  A. Colombo University of Bergamo, Department of Industrial Engineering, Viale Marconi 5, 24044 Dalmine, Bergamo, Italy e-mail: francesco.bassi@unibg.it; lorenzo.botti@unibg.it; alessandro.colombo@unibg.it A. Ghidoni ()  S. Rebay University of Brescia, Department of Industrial and Mechanical Engineering, via Branze 38, 25123 Brescia, Italy e-mail: antonio.ghidoni@ing.unibs.it; stefano.rebay@ing.unibs.it M. Azaïez et al. (eds.), Spectral and High Order Methods for Partial Differential Equations - ICOSAHOM 2012, Lecture Notes in Computational Science and Engineering 95, DOI 10.1007/978-3-319-01601-6__9, © Springer International Publishing Switzerland 2014 125