A general inflow turbulence generator for large eddy simulation

This paper presents a general inflow turbulence generator for numerical simulation of a spatially correlated turbulent flow field. The novel inflow turbulence generator is developed based on the discretizing and synthesizing random flow generation (DSRFG) technique that is proved to be able to generate a fluctuating turbulent flow field satisfying any given spectrum. Then, the techniques of aligning and remapping are incorporated in the inflow turbulence generator for generation of an inhomogeneous and anisotropic turbulent flow field following arbitrary target spectra in three orthogonal directions. The performance of the present inflow turbulence generator is compared with that of Smirnov’s random flow generation (RFG) method. Detailed numerical studies show that the proposed inflow turbulence generator can strictly guarantee divergence-free condition without any additional improving step and synthetically generate inflows satisfying prescribed spatial anisotropy and correlation conditions. It is demonstrated through numerical examples that the inflow turbulence generator developed in this study is an effective tool for generation of a spatially correlated turbulent flow field for large eddy simulation (LES).