Experimental evidence for intense vortical structures in grid turbulence.
J. D. Jacob and Ö. Savas
Zeitschrift fur Angewandte Mathematik und Physik (ZAMP),
1995, 46, pp. 699-716.
An instantaneous local quantification scheme is employed to investigate the vortical structure of the turbulent flow behind a grid. Reflected light fields from thin flakes are used to infer the local curvature and the degree of tightness of the stream surfaces intersecting the plane of observation. There are highly localized regions of tightly wound stream surfaces which we interpret as probable sites of intense localized vortical structures.