On a new simplicity of turbulence

摘要

The theoretical study of turbulence during the past few decades has been focused on the understanding of the physical processes of the energy cascade to small scales, which is crucial for meaningfully modeling the correlations between large and small-scale fluctuations and for deriving reduced effective systems describing the large-scale structures in turbulent systems. It is now recognized that turbulent cascade is generally intermittent with a mixture of random events and coherent dynamics. The later is related to the development of singular structures often observed (numerically and experimentally) in the regions of intense fluctuations in, for instance, a turbulent vorticity field. Such a mixture of orders and disorders exhibit nonlinear multi-scaling behavior; therefore, the scaling laws are generally qualified as anomalous.