Publisher: Cambridge University Press
Print Publication Year: 2002
Online Publication Date:July 2010
Chapter DOI: http://dx.doi.org/10.1017/CBO9780511755385.015
This chapter develops the somewhat controversial opinion that, at present and in the near future, industry is not likely to use LES for actual engineering applications, despite, or rather because of, the daily use of (RANS) CFD. While the effect of subgrid-scale models is small, there is a need for further improvement of numerical schemes in complex geometry, and some steps in this direction are presented. Finally some test-cases of industrial relevance are presented in the frame of acoustics and fluid-structure interaction. These are among the few niches left vacant by RANS where industry might spend the large computing and staff-time resources required for conducting a complex LES.
Despite widespread academic use of LES, there are still very few ‘industrial’ LES calculations. In the year 2000, following a decade in which LES has been touted as the route for by-passing turbulence model limitations, it still needs to be shown that industry is ready to invest its own resources, manpower and computing, to resolve, via LES, a relevant engineering problem, without either the incentive of external funding, or for the sake of pure research investigations. We do not count here as ‘industrial’ the proactive government initiatives such as state- or EU-funded projects, or the ASCI project in the US.
Industry has taken advantage of increased computer power to model more realistic geometries and complex physical processes rather than resorting to advanced turbulence modelling, either LES or RANS (Reynolds-averaged Navier–Stokes). Even second-moment closures are often regarded as too demanding. In power plants for instance, it has been realised that isolating a component for a numerical simulation always results in crude approximations concerning the inlet conditions.