IJPAM: Volume 41, No. 4 (2007)

HIERARCHICAL VORTICAL STRUCTURES IN
A HOMOGENEOUS ISOTROPIC TURBULENT FLOW

S. Izawa$^1$, W.A. Kareem$^2$, M. Shigeta$^3$, Y. Fukunishi$^4$
$^{1,3,4}$Faculty of Engineering
Tohoku University
Sendai, 980-8579, JAPAN
$^1$e-mail: izawa@fluid.mech.tohoku.ac.jp
$^2$Suez Canal University
Suez, EGYPT
e-mail: waleed_sayed_2000@yahoo.com


Abstract.Hierarchical vortices are extracted from a forced homogeneous isotropic turbulent field, and an automatic tracking of each vortex is attempted. The skeleton of each vortex is also defined by connecting the geometric centers of its structure. The Fourier low-pass filter is applied to the velocity field to extract structures of different scales. The automatic vortex-tracking scheme shows the capability of handling vortices even when they split into pieces, and the shapes of extracted skeleton agree well with those of the vortices.

Received: September 12, 2007

AMS Subject Classification: 76F05

Key Words and Phrases: turbulent flow, Fourier low-pass filter, extraction, tracking, skeleton

Source: International Journal of Pure and Applied Mathematics
ISSN: 1311-8080
Year: 2007
Volume: 41
Issue: 4