Implicit Large eddy simulation of wind flow over rough terrain

Atmospheric boundary layer (ABL) flow over a rough terrain is studied numerically. A drag force model is employed to represent surface roughness. The spectral vanishing viscosity (SVV) method is adopted for implicit large eddy simulation (ILES). These techniques enable us to capture the dominant features of turbulent flow over non-smooth terrain with inhomogeneous roughness at high Reynolds number without resolving the very fine scale turbulence near the wall. We then run a test case of wind resource assessment on rough terrain, namely ABL flow over a hill with small-scale surface roughness at Re = 10⁶ (Re is defined based on hill height). The instantaneous flow, mean flow and Reynolds stress are analysed in order to interprete the obtained turbulent flow. The effect of roughness length and associated drag coefficient are also evaluated.