PROPAGATION OF GRID TURBULENCE IN HOMOGENEOUS FLUIDS

Citation
Si. Voropayev et Hjs. Fernando, PROPAGATION OF GRID TURBULENCE IN HOMOGENEOUS FLUIDS, Physics of fluids, 8(9), 1996, pp. 2435-2440
Citations number
20
Categorie Soggetti
Mechanics,"Phsycs, Fluid & Plasmas
Journal title
ISSN journal
10706631
Volume
8
Issue
9
Year of publication
1996
Pages
2435 - 2440
Database
ISI
SICI code
1070-6631(1996)8:9<2435:POGTIH>2.0.ZU;2-R
Abstract
The purpose of this paper is to present the results of a laboratory ex periment dealing with one-dimensional propagation of a turbulent front induced by an oscillating grid in a homogeneous fluid. The symmetrica l quadrupolar mode of the flow, induced by the grid elements, was stud ied in the range KC=4-45, S=1-20 (KC is the Keulegan-Carpenter number, S is the Stokes number). It is shown that the depth H of the turbulen t layer increases with time t as H proportional to t(1/2). Experimenta l data for different grid parameters and oscillation amplitudes and fr equencies are presented in the nondimensional form h=const tau(1/2), u sing nondimensional depth h of the turbulent layer and nondimensional time tau. A semiempirical model is presented to explain this behavior. This model is based on the properties of a flow induced in a visous f luid by localized forcing of a line force dipole (force doubler). (C) 1996 American Institute of Physics.