Physics of Fluids - Publications

Response maxima in time-modulated turbulence: Direct numerical simulations

arΧiv
Europhysics Letters 73, 851 (2006)

Authors

	A. K. Kuczaj
	B. J. Geurts
	Detlef Lohse

BibTeΧ

@article{0295-5075-73-6-851,
  author={A. K. Kuczaj and B. J. Geurts and D. Lohse},
  title={Response maxima in time-modulated turbulence: Direct numerical simulations},
  journal={EPL (Europhysics Letters)},
  volume={73},
  number={6},
  pages={851},
  url={http://stacks.iop.org/0295-5075/73/i=6/a=851},
  year={2006},
  abstract={The response of turbulent flow to time-modulated forcing is studied by direct numerical simulations of the Navier-Stokes equations. The large-scale forcing is modulated via periodic energy input variations at frequency ω. The response is maximal for frequencies in the range of the inverse of the large eddy turnover time, confirming the mean-field predictions of von der Heydt, Grossmann and Lohse ( Phys. Rev. E , 67 (2003) 046308). In accordance with the theory the response maximum shows only a small dependence on the Reynolds number. At sufficiently high frequencies the amplitude of the kinetic energy response decreases as 1/ω. For frequencies beyond the range of maximal response, a significant change in the phase-shift relative to the time-modulated forcing is observed. For large ω the phase shift approaches roughly 90° for the total energy and 180° for the energy dissipation rate.}
}