Intermittency of Passive Advection†
نویسندگان
چکیده
An explanation of the origin of intermittency in the fully developed turbulence remains one of the main open problems of theoretical hydrodynamics. Quantitatively, intermittency is measured by deviations from Kolmogorov’s scaling of the velocity correlators. Below, we shall describe a recent progress in the understanding of intermittency in a simple system describing the passive advection of a scalar quantity (temperature, density of a pollutant) by a random velocity field. The system, maintained in a stationary state by a large scale source, exhibits a down-scale energy cascade. If the molecular diffusion is small, an intermittent inertial range sets in [1]. We shall explain this phenomenon by identifying the origin of the anomalous scaling of scalar correlators in a simple model of passive advection due to Kraichnan [2].
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