Onset criteria for freely decaying isotropic turbulence

S. R. Yoffe, W. D. McComb

Research output: Contribution to journalArticle

5 Citations (Scopus)
19 Downloads (Pure)

Abstract

From direct numerical simulation (DNS) of turbulence decaying from specified initial conditions for the range of initial Taylor-Reynolds numbers 2.58 ≤ Rλ(0) ≤ 358.6, it was found that the shape of the iconic curve of dimensionless dissipation versus Reynolds number depended strongly on the choice of measurement time. For our preferred time, a composite based on peak values in the dissipation and inertial transfer curves, the result was virtually identical to the forced, stationary case. In order to try varying the initial conditions, an additional run was performed, using the data from a stationary, forced simulation with Rλ = 335 for the initial condition. The results of this suggested that the time taken for energy to pass through the cascade was about one half of an initial eddy turnover time. In the course of studying onset criteria, we found that the exponent for the power-law decay of the energy decreased with increasing Reynolds number and lay in the range 1.35 ≤ n ≤ 2.60.
Original languageEnglish
Article number104605
Number of pages27
JournalPhysical Review Fluids
Volume3
DOIs
Publication statusPublished - 15 Oct 2018

Keywords

  • homogeous isotropic turbulence
  • decaying turbulence
  • evolved turbulence
  • direct numerical simulation

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