A GENERAL-CLASS OF COMMUTATIVE FILTERS FOR LES IN COMPLEX GEOMETRIES

A class of filters for large eddy simulations of turbulent inhomogeneo us flows is presented. A general set of rules for constructing discret e filters in complex geometry is given and examples of such filters ar e presented. With these filters the commutation error between numerica l differentiation and filtering can be made arbitrarily small, allowin g for derivation of a consistent set of equations for the large scale field. The application of such filters for explicit filtering in large eddy simulations and the issue of boundary conditions for the filtere d field are also discussed. (C) 1998 Academic Press.