Universal aspects of small-scale motions in turbulence
GE Elsinga, I Marusic
Journal of Fluid Mechanics | CAMBRIDGE UNIV PRESS | Published : 2010
Two aspects of small-scale turbulence are currently regarded universal, as they have been reported for a wide variety of turbulent flows. Firstly, the vorticity vector has been found to display a preferential alignment with the eigenvector corresponding to the intermediate eigenvalue of the strain rate tensor; and secondly, the joint probability density function (p.d.f.) of the second and third invariant of the velocity gradient tensor, Q and R, has a characteristic teardrop shape. This paper provides an explanation for these universal aspects in terms of a spatial organization of coherent structures, which is based on an evaluation of the average flow pattern in the local coordinate system ..View full abstract
The Australian Research Council and the Dutch Stichting FOM are gratefully acknowledged for their financial support. The authors would like to thank Professor Roger Fosdick and the reviewers for their helpful comments.