Embedded LES Methodology for General-Purpose CFD Solvers

The goal of this paper is to describe the implementation of an embedded LES module into an industrial CFD solver. In this technique, the Large Eddy Simulation approach exists as a sub-domain within a broader RANS domain. The approach itself poses several challenges, both from the physical modelling point of view, as well as from the point of code organization and infrastructure. The main physics challenges are present at the interfaces between RANS and LES zones and special attention will be given to those aspects in this paper. The main motivation behind this work is to answer the question whether such technique can be used as a general predicting tool for industrial turbulent flows. The following flows have been considered: fully developed pipe, channel flow and flow over a backward facing step. It is shown that this technique coupled with suitable solver technology is capable of delivering accurate results across different test cases. This in turn means that with increasing computer power, it can serve as a practical bridge between full RANS and full LES simulations.