Effect of vorticity on second- and third-order statistics of passive scalar gradients.
The influence of vorticity on second- and third-order moments of the spatial derivatives of a forced, passive scalar field has been studied in the framework of a simplified problem; the analysis is restricted to dominating rotation and molecular diffusion is represented by a linear model. The results reveal that, in the case of a passive scalar experiencing forcing in an isotropic medium, both vorticity and diffusion counteract anisotropy imposed on the scalar field. Anisotropy at the level of second-order moments appears to be destroyed essentially by the action of vorticity.
Gonzalez
Michel
M
CNRS UMR 6614/CORIA, Université de Rouen, Site Universitaire du Madrillet, Boîte Postale 12, Avenue de l'Université, 76801 Saint-Etienne du Rouvray Cedex, France.