1.
Phys Rev Lett
; 105(4): 044503, 2010 Jul 23.
Article
in English
| MEDLINE
| ID: mdl-20867848
ABSTRACT
We periodically modulate a turbulent wind-tunnel flow with an active grid. We find a resonant enhancement of the mean turbulent dissipation rate at a modulation frequency which equals the large-eddy turnover rate. Thus, we find the best frequency to inject energy into a turbulent flow. The resonant response is characterized by the emergence of vortical structures in the flow and depends on the spatial mode of the stirring grid.