Assessment of URANS, SAS, and IDDES on the bi-stable wake flow of a generic ship

Abstract

The present study aims to assess the prediction ability of URANS (unsteady Reynolds-averaged Navier-Stokes), SAS (scale-adaptive simulation), and IDDES (improved delayed detached-eddy simulation) on the naturally asymmetric flow of a generic ship model. The inlet velocity gives a Reynolds number of 8 × 104 based on the ship width. Experimental results are used as the baseline to judge the accuracy of these modelling techniques. The findings indicate that all techniques can predict the flow asymmetry of the ship wake, although URANS is less accurate due to its inability to resolve small-scale flow structures. Furthermore, IDDES is found to be more accurate than SAS considering the extent of wake asymmetry. Therefore, IDDES is recommended when higher accuracy is needed despite its higher computational demand.