Self-truncation and scaling in Euler-Voigt-$\alpha$ and related fluid models

Abstract

A generalization of the $3D$ Euler-Voigt-$\alpha$ model is obtained by introducing derivatives of arbitrary order $\beta$ (instead of $2$) in the Helmholtz operator. The $\beta \to \infty$ limit is shown to correspond to Galerkin truncation of the Euler equation. Direct numerical simulations (DNS) of the model are performed with resolutions up to $2048^3$ and Taylor-Green initial data. DNS performed at large $\beta$ demonstrate that this simple classical hydrodynamical model presents a self-truncation behavior, similar to that previously observed for the Gross-Pitaeveskii equation in Krstulovic and Brachet [Phys. Rev. Lett. 106, 115303 (2011)]. The self-truncation regime of the generalized model is shown to reproduce the behavior of the truncated Euler equation demonstrated in Cichowlas et al. [Phys. Rev. Lett. 95, 264502 (2005)]. The long-time growth of the self-truncation wavenumber $k_{\mathrm{st}}$ appears to be self-similar. Two related $\alpha$-Voigt versions of the EDQNM model and the Leith model are introduced. These simplified theoretical models are shown to reasonably reproduce intermediate time DNS results. The values of the self-similar exponents of these models are found analytically.

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References in corpus (4)

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• Dynamics of spectrally truncated inviscid turbulence
• Two-fluid model of the truncated Euler Equations
• A paradigmatic flow for small-scale magnetohydrodynamics: properties of the ideal case and the collision of current sheets

Cited by in corpus (3)

• On Unique Ergodicity in Nonlinear Stochastic Partial Differential Equations
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