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arXiv · 1808.00578

Condensates in thin-layer turbulence

Adrian van Kan·Alexandros Alexakis
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Abstract

We examine the steady state of turbulent flows in thin layers using direct numerical simulations. It is shown that when the layer thickness is smaller than a critical height, an inverse cascade arises which leads to the formation of a steady state condensate where most of the energy is concentrated in the largest scale of the system. For layers of thickness smaller than a second critical height, the flow at steady state becomes exactly two-dimensional. The amplitude of the condensate is studied as a function of layer thickness and Reynolds number. Bi-stability and intermittent bursts are found close to the two critical points. The results are interpreted based on a mean field three-scale model that reproduces some of the basic features of the numerical results.

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Adrian van Kan, Alexandros Alexakis. 2019-03-13. Condensates in thin-layer turbulence. https://doi.org/10.1017/jfm.2019.29

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