Measurements of the Kolmogorov constant and intermittency exponent at very high Reynolds numbers

Characteristics of turbulence in the inertial range are experimentally studied in the atmospheric surface layer over the range of the Taylor microscale based Reynolds number Rλ≊(2.8–12.7)×103 and in a large wind tunnel (in a mixing layer at Rλ≊2.0×103 and a return channel at Rλ≊3.2×103). The intermittency exponent μ, estimated from the correlation function of energy dissipation Rεε(r)=〈ε(x)ε(x+r)〉∝r−μ, is found to be independent of Reynolds number and approximately equal to 0.20. No ‘‘measurable’’ deviation from the −5/3 exponent in the ‘‘five-thirds’’ law is found. On the other hand, the Kolmogorov constant C in this law is found to be weakly dependent on Rλ. This dependence is well described by the power law C∝R−μ/2λ≊R−0.10λ at μ≊0.20.