Hybrid two-level large-eddy simulation of turbulent flow in a channel, past a bump and around an inclined prolate spheroid

Abstract

The hybrid two-level large-eddy simulation method, a multi-scale formulation for simulation of turbulent flows, is used in this study to investigate flows at practically relevant Reynolds number. We simulate three flow configurations, ranging from canonical to complex geometries. These cases include, fully developed turbulent flow in a periodic channel, weakly separating/reattaching flow past a bump placed on the lower surface of a channel and flow around an inclined prolate spheroid. The chosen flow geometries are representative examples of flow observed in practical applications, where features such as near-wall turbulence dynamics, separation/reattachment, presence of non-equilibrium turbulence, skewed boundary layers etc., pose a challenging task to conventional numerical methods to accurately and consistently capture them. The hybrid two-level large-eddy simulation method blends the two-level simulation model with a conventional large-eddy simulation approach and is designed to alleviate some of the limitations associated with the conventional large-eddy simulation approach. The method has been validated in the past by simulating low to moderately high Reynolds number turbulent flows under wide variety of conditions. Here, we demonstrate the predictive ability of the method by simulating three different flows with varying level of complexity at practically relevant Reynolds number and comparing the results with the available data. In particular, we analyze the instantaneous flow features, smalland large-scale characteristics and the turbulence statistics.