Simulated flow around a rectangular 5:1 cylinder: Spanwise discretisation effects and emerging flow features

In the present contribution, a systematic parametrical study on the spanwise length of the computational domain and on the spanwise grid density is proposed in the framework of the Benchmark on the Aerodynamics of a Rectangular 5:1 Cylinder (BARC). The study aims at evaluating the effects of these computational features on the simulated flow field in terms of bulk parameters, spanwise-averaged distributions, correlation coefficient and correlation length. The effectiveness of the adopted computational approach to provide the correlation measures is discussed. In particular, dense spanwise grids seem to be a key element to simulate some emerging and unexpected features of the cylinder aerodynamic behaviour, such as the asymmetry of the time-averaged flow field.

► Computational simulation of the flow around a rectangular 5:1 cylinder. ► The study develops in the framework of the BARC benchmark. ► Parametrical study on the spanwise features of the computational domain. ► Analysis of bulk parameters, spanwise-averaged distributions, correlation coefficient. ► Asymmetry of the time-averaged flow field around the nominally symmetric setup.