LARGE EDDY SIMULATION OF COMPLEX TURBULENT FLOWS:PHYSICAL ASPECTS AND RESEARCH TRENDS

In the current paper,we have primarily addressed one powerful simu-lation tool developed during the last decades——Large Eddy Simulation (LES),whichis most suitable for unsteady three-dimensional complex turbulent flows in industryand natural environment.The main point in LES is that the large-scale motion isresolved while the small-scale motion is modeled or,in geophysical terminology,pa-rameterized.With a view to devising a subgrid-scale(SGS) model of high quality,wehave highlighted analyzing physical aspects in scale interaction and energy transfersuch as dissipation,backscatter,local and non-local interaction,anisotropy and res-olution requirement.They are the factors responsible for where the advantages anddisadvantages in existing SGS models come from. A case study on LES of turbu-lence in vegetative canopy is presented to illustrate that LES model is more based onphysical arguments.Then,varieties of challenging complex turbulent flows in bothindustry and geophysical fields in the near future are presented.In conclusion,wemay say with confidence that new century shall see the flourish in the research ofturbulence with the aid of LES combined with other approaches.