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The large-scale flow structure and the turbulent transfer of heat and momentum are directly measured in highly turbulent liquid metal convection experiments for Rayleigh numbers varied between $4 \times 10^5$ and $\leq 5 \times 10^9$ and…

Fluid Dynamics · Physics 2022-05-04 Felix Schindler , Sven Eckert , Till Zürner , Jörg Schumacher , Tobias Vogt

Large-scale circulation (LSC) quasi-stably emerges in the turbulent Rayleigh-B\'{e}nard convection, and intermittently reverses its rotational direction in two-dimensional turbulent convection. In this paper, direct numerical simulations of…

Fluid Dynamics · Physics 2025-05-06 Daigaku Katsumi , Masanobu Inubushi , Naoto Yokoyama

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

A removable holder carrying a set of miniature temperature sensors inside our Rayleigh-B\'enard convection cylindrical cell has been developed. The sensors should not disturb the temperature and velocity fields of the buoyancy-driven…

Fluid Dynamics · Physics 2022-04-04 Pavel Hanzelka , Ivan Vlcek , Pavel Urban

We report on the transition between two regimes of heat transport in a radiatively driven convection experiment, where a fluid gets heated up within a tunable heating length $\ell$ in the vicinity of the bottom of the tank. The first regime…

Fluid Dynamics · Physics 2020-10-22 V. Bouillaut , S. Lepot , S. Aumaître , B. Gallet

Thermal convection of fluid is a more efficient way than diffusion to carry heat from hot sources to cold places. Here, we experimentally study the Rayleigh-B\'enard convection of aqueous glycerol solution in a cubic cell with suspensions…

Fluid Dynamics · Physics 2021-09-14 Shi-Yuan Hu , Kai-Zhe Wang , Lai-Bing Jia , Jin-Qiang Zhong , Jun Zhang

We investigate the large-scale circulation (LSC) of turbulent Rayleigh-B\'enard convection in a large box of aspect ratio $\Gamma =32$ for Rayleigh numbers up to $Ra=10^9$ and at a fixed Prandtl number $Pr=1$. A conditional averaging…

We investigate the influence of the temperature boundary conditions at the sidewall on the heat transport in Rayleigh-B\'enard (RB) convection using direct numerical simulations. For relatively low Rayleigh numbers Ra the heat transport is…

Fluid Dynamics · Physics 2014-12-24 Richard J. A. M. Stevens , Detlef Lohse , Roberto Verzicco

Measurements of the Nusselt number $Nu$ and of temperature variations $\Delta T_b$ in the bulk fluid are reported for turbulent Rayleigh-B\'enard convection of a cylindrical sample. They cover the Rayleigh-number range $10^{9} \alt Ra \alt…

Fluid Dynamics · Physics 2009-04-17 Denis Funfschilling , Eberhard Bodenschatz , Guenter Ahlers

A statistical-mechanical investigation is performed on Rayleigh-B\'enard convection of a dilute classical gas starting from the Boltzmann equation. We first present a microscopic derivation of basic hydrodynamic equations and an expression…

Statistical Mechanics · Physics 2007-05-23 Takafumi Kita

This study explores heat and turbulent modulation in three-dimensional multiphase Rayleigh-B\'enard convection using direct numerical simulations. Two immiscible fluids with identical reference density undergo systematic variations in…

Fluid Dynamics · Physics 2024-08-26 Abbas Moradi Bilondi , Nicolò Scapin , Luca Brandt , Parisa Mirbod

If a fluid flow is driven by a weak Gaussian random force, the nonlinearity in the Navier-Stokes equations is negligibly small and the resulting velocity field obeys Gaussian statistics. Nonlinear effects become important as the driving…

Fluid Dynamics · Physics 2018-10-01 Jörg Schumacher , Ambrish Pandey , Victor Yakhot , Katepalli R. Sreenivasan

We present mesoscale numerical simulations of Rayleigh-B\'enard (RB) convection in a two-dimensional model emulsion. The systems under study are constituted of finite-size droplets, whose concentration Phi_0 is systematically varied from…

The boundary layer structure of the velocity and temperature fields in turbulent Rayleigh-Benard flows in closed cylindrical cells of unit aspect ratio is revisited from a transitional and turbulent viscous boundary layer perspective. When…

Fluid Dynamics · Physics 2016-12-30 Jörg Schumacher , Vinodh Bandaru , Ambrish Pandey , Janet D. Scheel

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

We study turbulent Rayleigh-B\'enard convection over four decades of Rayleigh numbers 4E8 < Ra < 2E12, while harmonically modulating the temperatures of the plates of our cylindrical cell. We probe the flow by temperature sensors placed in…

Fluid Dynamics · Physics 2022-04-13 P. Urban , P. Hanzelka , T. Králík , V. Musilová , L. Skrbek

Heat and momentum transfer in wall-bounded turbulent flow, coupled with the effects of wall-roughness, is one of the outstanding questions in turbulence research. In the standard Rayleigh-B\'enard problem for natural thermal convection, it…

Fluid Dynamics · Physics 2019-07-05 Michael MacDonald , Nicholas Hutchins , Detlef Lohse , Daniel Chung

In this paper, we present results from an experimental study into turbulent Rayleigh-Benard convection forced externally by periodically modulated unidirectional rotation rates. We find that the azimuthal rotation velocity $\dot{\theta}$(t)…

Fluid Dynamics · Physics 2016-09-14 Sebastian Sterl , Hui-Min Li , Jin-Qiang Zhong

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 $Pr\approx0.0093$…

The heat transfer behavior of convection-driven dynamos in a rotating plane layer between two parallel plates, heated from below and cooled from the top, is investigated. At a fixed rotation rate (Ekman Number, $E=10^{-6}$) and fluid…

Fluid Dynamics · Physics 2022-06-08 Souvik Naskar , Anikesh Pal