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We numerically investigate turbulent Rayleigh-B\'enard convection with gas bubbles attached to the hot plate, mimicking a core feature in electrolysis, catalysis, or boiling. The existence of bubbles on the plate reduces the global heat…

Fluid Dynamics · Physics 2022-08-17 Hao-Ran Liu , Kai Leong Chong , Rui Yang , Roberto Verzicco , Detlef Lohse

We offer a unifying theory for turbulent purely internally heated convection, generalizing the unifying theories of Grossmann and Lohse (2000, 2001) for Rayleigh--B\'enard turbulence and of Shishkina, Grossmann and Lohse (2016) for…

Fluid Dynamics · Physics 2021-03-10 Qi Wang , Detlef Lohse , Olga Shishkina

We report an experimental study aiming to clarify the role of boundary conditions (BC) in high Rayleigh number $10^8 < {\rm{Ra}} < 3 \times 10^{12}$ turbulent thermal convection of cryogenic helium gas. We switch between BC closer to…

Fluid Dynamics · Physics 2021-08-11 P. Urban , T. Králík , M. Macek , P. Hanzelka , T. Věžník \and L. Skrbek

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 turbulent Rayleigh-B\'enard convection through direct numerical simulations in a three-dimensional plane layer of aspect ratio 4 for Rayleigh numbers $10^5 \leq Ra \leq 10^{11}$ and Prandtl number $Pr=0.7$. We summarize the…

Fluid Dynamics · Physics 2025-12-30 Roshan J. Samuel , Jörg Schumacher

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

Rayleigh-B{\'e}nard convection is investigated with sulfur hexafluoride (SF$_6$) in the vicinity of its critical point. In the supercritical domain, direct measurements of the heat flux $Q$ as a function of the temperature difference…

Fluid Dynamics · Physics 2025-03-12 Valentin Mouet , Guillaume Michel , François Pétrélis , Stephan Fauve

A series of numerical simulations of Rayleigh-B{\'e}nard convection in a cubic cavity are conducted in order to examine the structure of the thermal boundary layer in case of mixed boundary conditions. The main goal of the study is the…

Fluid Dynamics · Physics 2020-10-29 Andrei Sukhanovskii , Andrei Vasiliev

The effect of various velocity boundary condition is studied in two-dimensional Rayleigh-B\'enard convection. Combinations of no-slip, stress-free and periodic boundary conditions are used on both the sidewalls and the horizontal plates.…

Fluid Dynamics · Physics 2015-01-09 Erwin P. van der Poel , Rodolfo Ostilla Mónico , Roberto Verzicco , Detlef Lohse

In Rayleigh-B\'enard convection, it has been found that the amount of heat passing through the fluid has a power law dependence on the imposed temperature difference. Modifying this dependence, either enhancing or reducing the heat transfer…

Fluid Dynamics · Physics 2022-10-14 Jinzi Mac Huang , Jun Zhang

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…

Recent X-ray observations have revealed a universal temperature profile of the intracluster gas of non-cooling flow clusters which is flat for r \le 0.2 r_{180}. Numerical simulations, however, obtain a steeper temperature profile in the…

Astrophysics · Physics 2009-11-07 Biman B. Nath

We study the influence of thermal boundary conditions on large aspect ratio Rayleigh-B\'enard convection by a joint analysis of experimental and numerical data sets for a Prandl number $\mathrm{Pr = 7}$ and Rayleigh numbers $\mathrm{Ra =…

Fluid Dynamics · Physics 2023-09-15 Theo Käufer , Philipp P. Vieweg , Jörg Schumacher , Christian Cierpka

We investigate the structures of the near-plate velocity and temperature profiles at different horizontal positions along the conducting bottom (and top) plate of a Rayleigh-B\'{e}nard convection cell, using two-dimensional (2D) numerical…

Motivated by nuclear safety issues, we study the heat transfers in a thin cylindrical fluid layer with imposed fluxes at the bottom and top surfaces (not necessarily equal) and a fixed temperature on the sides. We combine direct numerical…

Fluid Dynamics · Physics 2024-01-17 Florian Rein , Laure Carénini , Florian Fichot , Benjamin Favier , Michael Le Bars

We present a numerical study of convection in a horizontal layer comprising a fluid-saturated porous bed overlain by an unconfined fluid layer. Convection is driven by a vertical, destabilising temperature difference applied across the…

Fluid Dynamics · Physics 2021-07-07 Thomas Le Reun , Duncan R. Hewitt

Inclined turbulent thermal convection by large Rayleigh numbers in extremely small-Prandtl-number fluids is studied based on results of both, measurements and high-resolution numerical simulations. The Prandtl number $Pr\approx0.0093$…

We report pore-scale statistical properties of temperature and thermal energy dissipation rate in a two-dimensional porous Rayleigh-B\'enard (RB) cell. High-resolution direct numerical simulations were carried out for the fixed Rayleigh…

Fluid Dynamics · Physics 2023-09-20 Ao Xu , Ben-Rui Xu , Heng-Dong Xi

We present an investigation of the root-mean-square (rms) temperature $\sigma_T$ and the rms velocity $\sigma_w$ in the bulk of Rayleigh-B\'enard turbulence, using new experimental data from the current study and experimental and numerical…

Fluid Dynamics · Physics 2019-09-18 Yi-Chao Xie , Bu-Ying-Chao Cheng , Yun-Bing Hu , Ke-Qing Xia

The aim of this paper is to contribute to the understanding and to model the processes controlling the amplitude of the wind of Rayleigh-Benard convection. We analyze results from direct simulation of an L/H = 4 aspect-ratio domain with…

Fluid Dynamics · Physics 2009-09-29 Maarten van Reeuwijk , Harm J. J. Jonker , Kemo Hanjalic