Decaying quasi-two-dimensional turbulence in a thin liquid layer

Abstract

The results of laboratory measurements of decaying quasi-two-dimensional turbulence in a thin liquid layer are considered. It is shown that the enstrophy-to-energy ratio decreases according to a power law on a certain decay interval. The exponent in the power law is a function of the Reynolds number. The enstrophy decay is found to be anomalously slow as predicted in a number of numerical studies. It is shown that the anomalous decay in the quasi-two-dimensional flow under investigation is not due to intense vortex formation as in the numerical decaying turbulence, but due to the limited range of scales on which a flow can be regarded as two-dimensional.