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arXiv · 2404.18894

Odd viscosity suppresses intermittency in direct turbulent cascades

Sihan Chen·Xander M. de Wit·Michel Fruchart·Federico Toschi·Vincenzo Vitelli
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Abstract

Intermittency refers to the broken self-similarity of turbulent flows caused by anomalous spatio-temporal fluctuations. In this Letter, we ask how intermittency is affected by a non-dissipative viscosity, known as odd viscosity (also Hall or gyro-viscosity), which appears in parity-breaking fluids such as magnetized polyatomic gases, electron fluids under magnetic field and spinning colloids or grains. Using a combination of Navier-Stokes simulations and theory, we show that intermittency is suppressed by odd viscosity at small scales. This effect is caused by parity-breaking waves, induced by odd viscosity, that break the multiple scale invariances of the Navier-Stokes equations. Building on this insight, we construct a two-channel helical shell model that reproduces the basic phenomenology of turbulent odd-viscous fluids including the suppression of anomalous scaling. Our findings illustrate how a fully developed direct cascade that is entirely self-similar can emerge below a tunable length scale, paving the way for designing turbulent flows with adjustable levels of intermittency.

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Sihan Chen, Xander M. de Wit, Michel Fruchart, Federico Toschi, Vincenzo Vitelli. 2024-04-29. Odd viscosity suppresses intermittency in direct turbulent cascades. https://doi.org/10.1103/physrevlett.133.144002

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