AN INVESTIGATION OF APPROPRIATE LES METHOD FOR WIND FLOW OVER TWO-DIMENSIONAL TOPOGRAPHY

Abstract

Turbulent flow past a complex topography, represented by an idealized two-dimenional hill with gentle slope is simulated by LES technique. Flow Reynolds number is moderately high to exhibit difficulties in the mostly sought boundary conditions in LES of practical flows. Simulations are performed to illustrate inadequacies of the commonly used boundary conditions and a modification is suggested that include pressure gradient effects. It is found from this study that the log-law modified to account for the local and instantaneous pressure gradient effects is a better alternative to the conventional log-law and non-slip conditions.