Large-Eddy Simulation of Turbulent Flow over Wavy Wall with Different Wave Steepness

Abstract

Large-eddy simulation (LES) with dynamic one-equation subgrid-scale stress model was utilized to study the characteristics of turbulent flow over sea-surface generalized as two-dimensional wavy wall with different wave steepness. The statistical characteristics of turbulent field and pressure distribution were presented in detail. The simulation results showed that the separation zones induce stronger convection as the wave steepness increases. Reynolds shear stress near the wall boundary showed positive correlation with the wave steepness, while in the outer region, time-averaged turbulent fields seemed to be insensitive with the wall boundary. The equivalent velocity profiles obtained from the spatial averaging of the time-averaged velocity indicated that lower velocity occurred as the increase of wave steepness due to the increased pressure-induced form drag. The vortex structures were also visualized and showed vertically-bent characteristics which induced negative Reynolds shear stress at the stoss side as the increase of wave steepness that is equivalent to the effect of wave age.