ILES, DDES and URANS Simulations of the Separated Flow Around a Circular Cylinder: A Comparative Study

Abstract

Numerical simulations using ILES, DDES and URANS, respectively, have been carried out to study the wake flow of a circular cylinder at Reynolds number of 3900. The three-dimensional compressible Favre-filtered/averaged Navier-Stokes equations are solved using Roe scheme for flux difference splitting and WENO scheme for reconstruction. The Sparlart-Allmaras one-equation turbulence model is adopted for the DDES and URANS simulations. Comparative studies are carried out based on mean flow quantities, mean integral quantities and turbulence statistics. Based on comparison between the predicted results and experimental measurements, the ILES/LES, DDES using fifth-order WENO scheme with minimum dissipation are found to be adequate to predict the complex flow field. However, the URANS method is found to be not able to reproduce such complex flow. The influences of the SGS model, parameter ε and order of WENO scheme have also been investigated. It is found that the SGS model has a small impact on the LES simulation, and ILES could give results closer to the experiment than LES with a SGS model. The parameter ε and the order of WENO scheme are found to have a strong impact on the simulations. A larger parameter ε and higher order are preferable to obtain a better prediction.