On the normalized turbulent energy dissipation rate

This paper revisits values of the normalized energy dissipation rate (C-epsilon) in different flows (two-dimensional wakes, grid turbulence, and homogeneous shear flow). Previously published as well as new data are considered over a relatively wide range of the Taylor-microscale Reynolds number R-lambda. C-epsilon exhibits wide scatter (in the range 0.5-2.5 for R-lambda > 50) although, for a given flow and initial conditions, it is independent of R-lambda when the latter is sufficiently large. An alternative definition [B. R. Pearson, P.-angstrom. Krogstad, and W. van de Water, Measurements of the turbulent energy dissipation rate, Phys. Fluids 14, 1288 (2002)] of C-epsilon has been checked in the same flows but has failed to yield a universal value for the coefficient. (c) 2005 American Institute of Physics.