Transitions in turbulent rotating Rayleigh-B\'enard convection

TL;DR

This paper investigates the transition criteria in rotating Rayleigh-Bénard convection, identifying a consistent parameter combination for flow regime changes using heat transport, and contrasting it with helicity-based criteria.

Contribution

It introduces a unified criterion based on heat transport for distinguishing flow regimes in rotating convection, applicable to different boundary conditions.

Findings

Transition occurs at the same parameter value for heat transport across boundary types.

Helicity-based transition criterion differs from heat transport-based one.

Flow regimes can be characterized by a specific combination of Reynolds, Prandtl, and Ekman numbers.

Abstract

Numerical simulations of rotating Rayleigh-B\'enard convection are presented for both no slip and free slip boundaries. The goal is to find a criterion distinguishing convective flows dominated by the Coriolis force from those nearly unaffected by rotation. If one uses heat transport as an indicator of which regime the flow is in, one finds that the transition between the flow regimes always occurs at the same value of a certain combination of Reynolds, Prandtl and Ekman numbers for both boundary conditions. If on the other hand one uses the helicity of the velocity field to identify flows nearly independent of rotation, one finds the transition at a different location in parameter space.