Numerical study on the three-dimensional unsteady flow past a 5:1 rectangular cylinder using the DES approach

Abstract

This paper deals with the detached-eddy simulation (DES) of the unsteady flow past a stationary two-dimensional rectangular cylinder with chord-to-thickness ratio B/D = 5.0 and perfectly sharp edges (R = 0), at low Mach number (M∞ = 0.1), moderately high Reynolds number (Re = 26,400 based on the body thickness D) and zero flow incidence (α = 0°). This geometry has often been assumed as a reference test case for studies dealing with bridge aerodynamics and aeroelasticity and, despite the simple geometry, it presents interesting and complex flow features. For these reasons it was chosen for the benchmark study BARC (Bartoli et al., 2008; Bruno et al., 2010; Mannini et al., 2010, 2011). In this work particular attention was devoted to the choice of the more appropriate algorithms to discretize the inviscid fluxes in the governing equations. The sensitivity of the solution to the amount of numerical dissipation introduced into the discretized equations was also studied.