The Persistent Clock of Turbulent Thermal Convection
Abstract
The large-scale circulation (LSC) of turbulent convection is a prominent feature of its dynamics and forms the basis for descriptive theories. We show, using experimental and numerical results from thermal convection in a cylindrical cell, that the LSC possesses a persistent internal `clock': its pulsating velocity as a function of time is described by a constant value of the parameter U/(lf) where U is the mean velocity, f the pulsation frequency, and l the characteristic length scale. By introducing a narrow sidewall barrier, we can trip the LSC, forming a pair of interconnected rolls stacked above and below the barrier. They independently exhibit the same value for the ratio U/(lf), even for vertically asymmetric pairs, indicating signs of synchrony. Thus, this parameter establishes a direct connection between plume-shedding dynamics and the flow topology.
Cite
@article{arxiv.2512.11669,
title = {The Persistent Clock of Turbulent Thermal Convection},
author = {Lázaro Martínez-Ortíz and Youri H. Lemm and Herman J. H. Clercx and Rudie P. J. Kunnen},
journal= {arXiv preprint arXiv:2512.11669},
year = {2025}
}