In three-dimensional hydrodynamic turbulence forced at large length scales, a constant
energy flux Π u flows from large scales to intermediate scales, and then to small scales. It is …

I first recall the theoretical background relevant to spectral truncation: absolute equilibrium in
helical flows and compressible effects. Thermalization phenomenology in Gross–Pitaevskii …

We present a numerical study of the statistical properties of three-dimensional dissipative
turbulent flows at scales larger than the forcing scale. Our results indicate that the large …

The spectrally truncated, or finite dimensional, versions of several equations of inviscid flows
display transient solutions which match their viscous counterparts, but which eventually lead …

We demonstrate that there is an optimal forcing length scale for low Prandtl number dynamo
flows that can significantly reduce the required energy injection rate. The investigation is …

Large-scale hydrodynamic instabilities of periodic helical flows of a given wave number K
are investigated using three-dimensional Floquet numerical computations. In the Floquet …

A generalization of the 3D Euler-Voigt-α model is obtained by introducing derivatives of
arbitrary order β (instead of 2) in the Helmholtz operator. The β→∞ limit is shown to …

We discuss the effect of different types of fluctuations on dynamos generated in the limit of
scale separation. We first recall that the magnetic field observed in the VKS (von Karman …

This manuscript describes how solutions of the Navier-Stokes equations behave in the large
scales when forced in the small scales. It analyzes also the large scale behavior of magnetic …