The purpose of this paper is to present the results of a laboratory experiment dealing with onehyphen;dimensional propagation of a turbulent front induced by an oscillating grid in a homogeneous fluid. The symmetrical quadrupolar mode of the flow, induced by the grid elements, was studied in the range KC=4ndash;45,S=1ndash;20 (KC is the Keuleganndash;Carpenter number,Sis the Stokes number). It is shown that the depthHof the turbulent layer increases with timetasHprop;t1/2. Experimental data for different grid parameters and oscillation amplitudes and frequencies are presented in the nondimensional formh=constthinsp;tgr;1/2, using nondimensional depthhof the turbulent layer and nondimensional time tgr;. A semiempirical model is presented to explain this behavior. This model is based on the properties of a flow induced in a visous fluid by localized forcing of a line force dipole (force doublet). copy;1996 American Institute of Physics.
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