Delayed correlation between turbulent energy injection and dissipation
Abstract
The dimensionless kinetic energy dissipation rate C_{ɛ} is estimated from numerical simulations of statistically stationary isotropic box turbulence that is slightly compressible. The Taylor microscale Reynolds number (Re_{λ}) range is 20≲Re_{λ}≲220 and the statistical stationarity is achieved with a random phase forcing method. The strong Re_{λ} dependence of C_{ɛ} abates when Re_{λ}≈100 after which C_{ɛ} slowly approaches ≈0.5 , a value slightly different from previously reported simulations but in good agreement with experimental results. If C_{ɛ} is estimated at a specific time step from the time series of the quantities involved it is necessary to account for the time lag between energy injection and energy dissipation. Also, the resulting value can differ from the ensemble averaged value by up to ±30% . This may explain the spread in results from previously published estimates of C_{ɛ} .
 Publication:

Physical Review E
 Pub Date:
 November 2004
 DOI:
 10.1103/PhysRevE.70.056301
 arXiv:
 arXiv:physics/0404114
 Bibcode:
 2004PhRvE..70e6301P
 Keywords:

 47.27.Ak;
 47.27.Jv;
 47.27.Nz;
 47.27.Vf;
 Fundamentals;
 HighReynoldsnumber turbulence;
 Physics  Fluid Dynamics;
 Astrophysics
 EPrint:
 7 pages, 7 figures. Submitted to Phys. Rev. E