Turbulence readily arises in numerous flows in nature and technology. The large number of degrees of freedom of turbulence poses serious challenges to numerical approaches aimed at simulating and controlling such flows. While the Navier-Stokes equations are commonly accepted to precisely describe fluid turbulence, alternative coarsened descriptions need to be developed to cope with the wide range of length and time scales. These coarsened descriptions are known as large-eddy simulations in which one aims to capture only the primary features of a flow, at considerably reduced computational effort. Such coarsening introduces a closure problem that requires additional phenomenological modeling. A systematic approach to the closure problem, known as regularization modeling, will be reviewed. Its application to turbulent mixing will be illustrated. Leray and LANSalpha regularization are discussed in some detail.
|Title of host publication||Turbulence and Interactions : proceedings of the TI 2012 conference|
|Editors||M.O. Deville, J-L. Estivalezes, V. Gleize, T-H. Lê, M. Terracol, S. Vincent|
|Place of Publication||Berlin Heidelberg|
|Number of pages||12|
|Publication status||Published - 2014|
|Name||Notes on Numerical Fluid Mechanics and Multidisciplinary Design|