Advances in large eddy simulation methodology for complex flows

Abstract

A review is provided of the recent advances in the derivation of the constitutive equations for large eddy simulation, subgrid scale modeling, wall modeling and applications of LES to turbulent combustion. The majority of the paper focuses on a review of two numerical methods for LES in complex geometry: the immersed boundary method and an unstructured mesh scheme. The latter scheme is applied to LES of a sector of a combustor of an operational gas turbine engine. Ó

Application of FDS and FireFOAM in Large Eddy Simulations of a Turbulent Buoyant Helium Plume

“…The convective terms are central differenced using a second order linear scheme. No purely upwind schemes were used since the use of unwinding in LES can introduce undesirable artificial numerical dissipation as has been noted by many studies [17]. This was also noted in the present study where different schemes were tested for discretizing the convective terms and it was evident in the simulations that any blending of the linear scheme with upwind resulted in high levels of numerical dissipation.…”

Using Image-based CFD to Investigate the Intracardiac Turbulence

“…Instead, in the present study, the Large Eddy Simulation approach is followed, taking advantage of the low-dissipative scheme of integration used in YALES2BIO. In this view, only the smallest scales are modelled (scales smaller than the mesh size) while the evolution of the large scales is computed by solving a filtered version of NSE [33,39,43]. In the latter, a subgrid-scale model must be used in order to account for the effect of the unresolved scales on the dynamics of the resolved ones.…”

Hybrid LES — Review and assessment

“…Even though LES enjoyed a great deal of success (Moin, 2002), it suffers from limited validity all the way up to the solid boundary, especially at high Reynolds numbers. The near-wall region in high Reynolds number turbulent flow contains vortical structures, which play a key role.…”