Influence of Vortex Structure and Dynamics on Turbulence Statistics at Large Scales

Katsunori Yoshimatsu, Koujiro Anayama and Yukio Kaneda

We examine the importance or unimportance of the role of vortices in the determination of turbulence statistics, on the basis of the method of the so-called `Computational Surgery'. Two fields, true and false fields, are generated. The true field obeys the Navier-Stokes (NS) equations for an incompressible fluid. In the false field, the NS dynamics are artificially modified so that the intense tube-like vortices are lost. Comparing the two fields, we may get some idea on the role of the vortices. The comparison so far made suggests that the statistics at large-scales are not sensitive to the exact vortex structure and dynamics at smaller scales.

Katsunori Yoshimatsu, associate professor à l'université de Nagoya (Japon)