Supergravitational turbulent thermal convection

TL;DR

This paper introduces a novel method to enhance thermal convection at high Rayleigh numbers by using centrifugal acceleration in a rapidly rotating cylindrical annulus, revealing new flow dynamics and heat transfer insights.

Contribution

It demonstrates a new experimental approach to achieve high effective gravity, exploring turbulent convection under strong rotational effects and revealing altered scaling laws.

Findings

Scaling exponent of Nusselt number exceeds one-third at high Rayleigh numbers

Convective rolls exhibit prograde revolution indicating zonal flow emergence

Method enables exploration of turbulent convection at unprecedented Rayleigh numbers

Abstract

High-Rayleigh number convective turbulence is ubiquitous in many natural phenomena and in industries, such as atmospheric circulations, oceanic flows, flows in the fluid core of planets, and energy generations. In this work, we present a novel approach to boost the Rayleigh number in thermal convection by exploiting centrifugal acceleration and rapidly rotating a cylindrical annulus to reach an effective gravity of 60 times Earth's gravity. We show that in the regime where the Coriolis effect is strong, the scaling exponent of Nusselt number versus Rayleigh number exceeds one-third once the Rayleigh number is large enough. The convective rolls revolve in prograde direction, signifying the emergence of zonal flow. The present findings open a new avenue on the exploration of high-Rayleigh number turbulent thermal convection and will improve the understanding of the flow dynamics and heat transfer processes in geophysical and astrophysical flows and other strongly rotating systems.