Uncovering the multifractality of Lagrangian pair dispersion in shock-dominated turbulence

Sadhitro De; Dhrubaditya Mitra; Rahul Pandit

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arXiv · 2311.06836

Uncovering the multifractality of Lagrangian pair dispersion in shock-dominated turbulence

Sadhitro De·Dhrubaditya Mitra·Rahul Pandit

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Abstract

Lagrangian pair dispersion provides insights into mixing in turbulent flows. By direct numerical simulations (DNS) we show that the statistics of pair dispersion in the randomly forced two-dimensional Burgers equation, which is a typical model of shock-dominated turbulence, is very different from its incompressible counterpart because Lagrangian particles get trapped in shocks. We develop a heuristic theoretical framework that accounts for this -- a generalization of the multifractal model -- whose prediction of the scaling of Lagrangian exit times agrees well with our DNS.

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Sadhitro De, Dhrubaditya Mitra, Rahul Pandit. 2023-11-12. Uncovering the multifractality of Lagrangian pair dispersion in shock-dominated turbulence. https://arxiv.org/abs/2311.06836

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