Laboratory Exploration of Heat Transfer Regimes in Rapidly Rotating Turbulent Convection

• Published in: arXiv.org 2020-09
• Main Authors: Cheng, Jonathan S, Madonia, Matteo, Aguirre Guzmán, Andrés J, Kunnen, Rudie P J
• Format: Article
• Language: English
• Subjects: Collapse; Computational fluid dynamics; Computer simulation; Fluid flow; Heat transfer; Phenomenology; Robustness (mathematics); Rotation; Temperature gradients; Turbulence
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1911.04537

We report heat transfer and temperature profile measurements in laboratory experiments of rapidly rotating convection in water under intense thermal forcing (Rayleigh number \(Ra\) as high as \(\sim 10^{13}\)) and unprecedentedly strong rotational influence (Ekman numbers \(E\) as low as \(10^{-8}\)). Measurements of the mid-height vertical temperature gradient connect quantitatively to predictions from numerical models of asymptotically rapidly rotating convection, separating various flow phenomenologies. Past the limit of validity of the asymptotically-reduced models, we find novel behaviors in a regime we refer to as rotationally-influenced turbulence, where rotation is important but not as dominant as in the known geostrophic turbulence regime. The temperature gradients collapse to a Rayleigh-number scaling as \(Ra^{-0.2}\) in this new regime. It is bounded from above by a critical convective Rossby number \(Ro^*=0.06\) independent of domain aspect ratio \(\Gamma\), clearly distinguishing it from well-studied rotation-affected convection.