Three-dimensional numerical simulation of a flat plate perpendicularly submitted to current with a blockage ratio of 0.214: URANS and DES

Abstract The uniform flow over a nominally two-dimensional normal thin flat plate with blockage ratio 0.214 was numerically investigated in three dimensions by methods: unsteady Reynolds-averaged Navier–Stokes (URANS) based on the realizable k–epsilon (RKE) turbulence model, URANS k–omega shear stress transport (SST) and detached eddy simulation (DES). Reynolds number inlet velocity chord width of 117,000. A comprehensive comparison against earlier experimental results showed that URANS-SST method only could give correct Strouhal but overestimated mean base pressure distribution drag coefficient, while URANS-RKE DES methods succeeded giving accurate predictions all. Moreover, comparing instantaneous vorticity contours three-dimensional (3D) turbulent structures, it is found better suited for present case because can capture irregular small-scale structures reproduce three-dimensionality low-frequency unsteadiness vortex shedding. Finally, through volume-of-fluid (VOF)-based free surface, demonstrated surface has no significant effect coefficient number.