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Two-dimensional simulations of Rayleigh-B\'enard convection at $Ra = 5\times10^{10}$ show that vertical logarithmic mean temperature profiles can be observed in regions of the boundary layer where thermal plumes are emitted. The profile is…

To understand turbulent convection at very high Rayleigh numbers typical of natural phenomena, computational studies in slender cells are an option if the needed resources have to be optimized within available limits. However, the…

Rayleigh-B\'enard convection in the turbulent regime is studied using statistical methods. Exact evolution equations for the probability density function of temperature and velocity are derived from first principles within the framework of…

Fluid Dynamics · Physics 2011-03-04 J. Lülff , M. Wilczek , R. Friedrich

Turbulent motions due to flux-driven thermal convection is investigated by numerical simulations and stochastic modelling. Tilting of convection cells leads to the formation of sheared flows and quasi-periodic relaxation oscillations for…

Fluid Dynamics · Physics 2020-08-26 G. Decristoforo , A. Theodorsen , O. E. Garcia

A coupled map lattice for convection is proposed, which consists of Eulerian and Lagrangian procedures. Simulations of the model not only reproduce a wide-range of phenomena in Rayleigh-B\'{e}nard convection experiments but also lead to…

chao-dyn · Physics 2015-06-24 Tatsuo Yanagita , Kunihiko Kaneko

Turbulent thermal convection is characterized by the formation of large-scale structures and strong spatial inhomogeneity. This work addresses the relative heat transport contributions of the large-scale plume ejecting versus plume…

Fluid Dynamics · Physics 2021-04-09 Philipp Reiter , Olga Shishkina , Detlef Lohse , Dominik Krug

We study the fine-scale statistics of temperature and its derivatives in turbulent Rayleigh-Benard convection. Direct numerical simulations are carried out in a cylindrical cell with unit aspect ratio filled with a fluid with Prandtl number…

Fluid Dynamics · Physics 2015-05-13 M. S. Emran , J. Schumacher

The dynamics in the thin boundary layers of temperature and velocity is the key to a deeper understanding of turbulent transport of heat and momentum in thermal convection. The velocity gradient at the hot and cold plates of a…

We study the connection between extreme events of thermal and kinetic energy dissipation rates in the bulk of three-dimensional Rayleigh-B\'{e}nard convection and the wall shear stress patterns at the top and the bottom planes that enclose…

Fluid Dynamics · Physics 2022-06-15 Valentina Valori , Joerg Schumacher

Turbulent Rayleigh-B\'enard convection displays a large-scale order in the form of rolls and cells on lengths larger than the layer height once the fluctuations of temperature and velocity are removed. These turbulent superstructures are…

Fluid Dynamics · Physics 2018-05-30 Ambrish Pandey , Janet D. Scheel , Jörg Schumacher

For rapidly rotating turbulent Rayleigh--B\'enard convection in a slender cylindrical cell, experiments and direct numerical simulations reveal a boundary zonal flow (BZF) that replaces the classical large-scale circulation. The BZF is…

Recent studies of rotating Rayleigh-B\'enard convection at high rotation rates and strong thermal forcing have shown a significant discrepancy in total heat transport between experiments on a confined cylindrical domain on the one hand and…

We study the evolution of a melting front between the solid and liquid phases of a pure incompressible material where fluid motions are driven by unstable temperature gradients. In a plane layer geometry, this can be seen as classical…

Fluid Dynamics · Physics 2019-01-15 Benjamin Favier , Jhaswantsing Purseed , Laurent Duchemin

We investigate by direct numerical simulation Rayleigh-B\'enard convection in a rotating rectangular cell with rotation vector and gravity perpendicular to each other. The flow is two dimensional near the onset of convection with convection…

Fluid Dynamics · Physics 2022-05-12 K. Lüdemann , A. Tilgner

Horizontally extended turbulent convection, termed mesoscale convection in natural systems, remains a challenge to investigate in both experiments and simulations. This is particularly so for very low molecular Prandtl numbers as in stellar…

Fluid Dynamics · Physics 2022-09-09 Ambrish Pandey , Dmitry Krasnov , Katepalli R. Sreenivasan , Jörg Schumacher

The shape of velocity and temperature profiles near the horizontal conducting plates in turbulent Rayleigh-B\'{e}nard convection are studied numerically and experimentally over the Rayleigh number range $10^8\lesssim…

We investigate convection in a thin cylindrical gas layer with an imposed flux at the bottom and a fixed temperature along the side, using a combination of direct numerical simulations and laboratory experiments. The experimental approach…

Fluid Dynamics · Physics 2025-03-13 Florian Rein , Laure Carénini , Florian Fichot , Benjamin Favier , Michael Le Bars

A fluid between two spheres, concentric or not, at different temperatures will flow in the presence of a constant gravitational force. Although there is no possible hydrostatic state, energy transport is dominated by diffusion if…

Fluid Dynamics · Physics 2015-09-22 A. D. Gallegos , C. Malaga

We report the results of high resolution direct numerical simulations of two-dimensional Rayleigh-B\'enard convection for Rayleigh numbers up to $\Ra=10^{10}$ in order to study the influence of temperature boundary conditions on turbulent…

Fluid Dynamics · Physics 2009-11-13 Hans Johnston , Charles R. Doering

The boundary layer flow in a Rayleigh-B\'enard convection cell of rectangular shape has been visualized in this fluid dynamics video. The experiment has been undertaken in air at a Rayleigh number $Ra=1.3\times 10^{10}$ and a Prandtl number…

Fluid Dynamics · Physics 2012-09-28 Ronald du Puits , Johannes Rilk , Christian Resagk , André Thess