Analysis of Detached-Eddy Simulation for the Flow Around a Circular Cylinder with Reference to PIV Data

A detailed validation study is presented for the detached-eddy simulation (DES) of the flow around a circular cylinder at a high sub-critical Reynolds number. Direct comparability with unsteady experimental field data is ensured by the confined and clearly-defined geometry. The combination of DES with an appropriate low-dissipative hybrid numerical convection scheme and high temporal resolution delivers excellent agreement with the experiment for the time and phase-averaged fields and spectral content. A strong sensitivity of the solution to the numerical time step size has been identified, which is attributed to time-filtering effects damping the development of resolved turbulence in the early shear layer. Recommendations are made concerning a CFL-type criterion for the temporal resolution of DES, and the remaining small discrepancies are attributed to a still insufficient time resolution, giving a clear direction to future studies.