A higher-order subfilter-scale model for large eddy simulation

This paper presents a new subfilter-scale stress model for large eddy simulation. The unknown velocity field is represented in terms of the filtered velocity by using a higher-order Padé approximation of the Fourier transform of the Gaussian filter. This accurate approximation of the velocity field yields an improved subfilter-scale stress tensor accounting for the information lost in the filtering process. The accuracy of the subfilter-scale stress tensor is especially important in the large eddy simulation of complex flows, such as geophysical flows, where the practical grid size is much larger than the scale of turbulent motion. We illustrate our approach through two simple one-dimensional numerical examples. We also present a rigorous mathematical analysis for this new large eddy simulation model.