Computing Turbulent Flow Dynamics With Implicit Large Eddy Simulation

Abstract

The Navier-Stokes equations (NSE) can be solved directly for laminar flows, but the wide range of eddy scales to be captured prohibits direct numerical simulation for the high Reynolds-number turbulent flows of technological interest. The prevalent remedy to this resolution problem has traditionally involved the Reynolds-averaged Navier-Stokes (RANS) approach, with averaging typically carried out over time or across an ensemble of equivalent flows. The applicability of RANS typically requires that time scales associated with organized unsteady motion be substantially larger than those of turbulent motion. Such statistically steady flow assumptions can be satisfied in many (e.g., low-frequency dominated) unsteady flow applications, but most turbulent flows of interest do not fall into this category.