Two-dimensionalization of the flow driven by a slowly rotating impeller in a rapidly rotating fluid

Abstract

We characterize the two-dimensionalization process in the turbulent flow produced by an impeller rotating at a rate $\omega$ in a fluid rotating at a rate $\Omega$ around the same axis for Rossby number $Ro=\omega /\Omega$ down to $10^{-2}$. The flow can be described as the superposition of a large-scale vertically invariant global rotation and small-scale shear layers detached from the impeller blades. As $Ro$ decreases, the large-scale flow is subjected to azimuthal modulations. In this regime, the shear layers can be described in terms of wakes of inertial waves traveling with the blades, originating from the velocity difference between the non-axisymmetric large-scale flow and the blade rotation. The wakes are well defined and stable at low Rossby number, but they become disordered at $Ro$ of order of 1. This experiment provides insight into the route towards pure two-dimensionalization induced by a background rotation for flows driven by a non-axisymmetric rotating forcing.

arXiv commentAccepted for publication in Physical Review Fluids

References in corpus (9)

• Dimensional transition in rotating turbulence
• Direct and inverse energy cascades in a forced rotating turbulence experiment
• Exact two-dimensionalization of rapidly rotating large-Reynolds-number flows
• Quantification of the strength of inertial waves in a rotating turbulent flow
• Disentangling inertial waves from eddy turbulence in a forced rotating turbulence experiment
• Rotating Taylor-Green Flow
• Influence of the multipole order of the source on the decay of an inertial wave beam in a rotating fluid
• Turbulent drag in a rotating frame
• The decay of Batchelor and Saffman rotating turbulence

Cited by in corpus (5)

• Cascades and transitions in turbulent flows
• Condensates in rotating turbulent flows
• Critical transition in fast-rotating turbulence within highly elongated domains
• Covariance and objectivity in mechanics and turbulence
• Effect of confinement on the transition from 2D to 3D fast rotating flows