The asymptotic state of decaying turbulence

Abstract: This talk is based on the paper with the same title as this talk, by Akash Rodhiya and the speaker, to appear in Phil. Trans. Roy. Soc. It concerns the long-time evolution of decaying homogeneous turbulence, which is a fundamental building block of the subject. The speaker and his co-author have investigated the problem by using a comprehensive suite of Direct Numerical Simulations, some of which are performed for unprecedented durations — up to 200,000 initial eddy-turnover times. They compare their findings with the theoretical work of the past, and with the recent theory developed by A. Migdal. A main conclusion is that the energy decay is significantly influenced by ``boundary effects", and that universality likely manifests only when these effects are removed. Alternatively, it may be more useful to discuss the universality of enstrophy decay.

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Bio: Prof. Katepalli Sreenivasan is a distinguished scientist who holds professorships in Physics, the Courant Institute of Mathematical Sciences, and the Tandon School of Engineering at New York University, where he also serves as University Professor and holds the Eugene Kleiner Chair for Innovation. Prof. Sreenivasan previously served as Director of the International Centre for Theoretical Physics in Trieste, Italy, and has held senior academic positions at Yale University and University of Maryland. He has received numerous international honours, including the Guggenheim Fellowship and the Otto Laporte Memorial Award of the American Physical Society, and has been elected to major scientific academies such as the United States National Academy of Sciences, and the United States National Academy of Engineering.