Large Eddy Simulations

Abstract

There is a priori no difficulty in envisaging a numerical resolution of the unstationary Navier Stokes equations in rotational situations: the various operators are represented by discrete systems relating the values taken by the velocity components, pressure, density, etc... on a space time grid. This grid may be spatially regular or irregular, with finite differences or finite elements methods. Often an orthogonal decomposition of the flow allows a spectral method to be used. In two dimensions the use of the stream function permits the elimination of the pressure. It is not the aim of the present monograph to describe the various numerical methods used in the so-called “Numerical Fluid Mechanics”. We will insist rather on the physical limitations which arise when such a simulation is performed on a turbulent flow.