Analytical calculations of Eulerian and Lagrangian time correlations in turbulent shear flows

摘要

The Taylor series expansion method is used to analytically calculate the Eulerian and Lagrangian time correlations in turbulent shear ows. The short-time behaviors of those correla- tion functions can be obtained from the series expansions. Especially, the propagation velocity and sweeping velocity in the elliptic model of space-time correlation are analytically calculated and further simplified using the sweeping hypothesis and straining hypothesis. These two characteristic velocities mainly determine the space-time correlations.