Large Eddy Simulations of Wall Bounded Turbulent Flows Using Unstructured Linear Reconstruction Techniques

Abstract

Largeeddy simulations (LES) of wall bounded, low Mach number turbulent flows are conducted using an unstructured finitevolume solver of the compressible flow equations. The numerical method employs linear reconstructions of the primitive variables based on the leastsquares approach of Barth. The standard Smagorinsky model is adopted as the subgrid term. The artificial viscosity inherent to the spatial discretization is maintained as low as possible reducing the dissipative contribution embedded in the approximate Riemann solver to the minimum necessary. Comparisons are also discussed with the results obtained using the implicit LES (ILES) procedure. Two canonical testcases are described: a fully developed pipe flow at a bulk Reynolds number Reb = 44 أ— 103 based on the pipe diameter, and a confined rotor–stator flow at the rotational Reynolds number Reخ©â€‰= 4 أ— 105 based on the outer radius. In both cases, the mean flow and the turbulent statistics agree well with existing direct numerical simulations (DNS) or experimental data.