Delayed correlation between turbulent energy injection and dissipation.
The dimensionless kinetic energy dissipation rate C(epsilon) is estimated from numerical simulations of statistically stationary isotropic box turbulence that is slightly compressible. The Taylor microscale Reynolds number (Re(lambda)) range is 20< or approximately equal to Re(lambda) < or approximately equal to 220 and the statistical stationarity is achieved with a random phase forcing method. The strong Re(lambda) dependence of C(epsilon) abates when Re(lambda) approximately 100 after which C(epsilon) slowly approaches approximately 0.5, a value slightly different from previously reported simulations but in good agreement with experimental results. If C(epsilon) 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(epsilon).
Pearson
Bruce R
BR
School of Mechanical, Materials, Manufacturing Engineering & Management, University of Nottingham, Nottingham NG7 2RD, United Kingdom. Bruce.Pearson@nottingham.ac.uk
Yousef
Tarek A
TA
Haugen
Nils Erland L
NE
Brandenburg
Axel
A
Krogstad
Per-Age
PA