The Imbalance Between Enstrophy Production and Destruction in Homogeneous Isotropic Unsteady Turbulence
We show in direct numerical simulations of homogeneous isotropic non-stationary turbulence that there is a systematic and significant imbalance between enstrophy production and its destruction which is concomitant with the previously observed imbalance between the non-linear energy cascade to fine scales and its dissipation (Valente, Onishi, da Silva, Phys Rev E 90(023003), 2014, ). However, contrary to the former, the imbalance between enstrophy production and destruction is affected by the ‘cascade time-lag’, i.e. the time it takes for the energy injected on the large-scales to reach the fine-scales.
KeywordsReynolds Number Direct Numerical Simulation Energy Cascade Direct Numerical Simulation Data Kinetic Energy Dissipation
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