APS -70th Annual Meeting of the APS Division of Fluid Dynamics- Event - Dissipation scales in Navier-Stokes turbulence using highly resolved Direct Numerical Simulations (DNS)

摘要

Recent work has shown that turbulent dissipation acquires strong fluctuations and other properties that maintain, even at low enough Reynolds numbers ($Re$), the same relationship with the inertial range, as if $Re$ is very high. In this work we further investigate these conclusions by using highly resolved DNS at a range of $Re$. We highlight the difficulties associated with investigating sub-Kolmogorov scales accurately from numerical as well as statistical standpoints. Results on the time evolution of dissipative modes are presented. The connection of this observation to large-scale and inertial-range dynamics is presented, pointing to potential shortcomings in determining coefficients of the presumed exponential roll off of energy spectrum. Further consequences of these findings are discussed.