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The structure of the boundary layers in turbulent Rayleigh-Benard convection is studied by means of three-dimensional direct numerical simulations. We consider convection in a cylindrical cell at an aspect ratio one for Rayleigh numbers of…

Fluid Dynamics · Physics 2012-09-04 Nan Shi , Mohammad S. Emran , Joerg Schumacher

We report a new thermal boundary layer equation for turbulent Rayleigh-Benard convection for Prandtl number Pr>1 that takes into account the effect of turbulent fluctuations. These fluctuations are neglected in existing equations, which are…

Fluid Dynamics · Physics 2015-06-23 Olga Shishkina , Susanne Horn , Sebastian Wagner , Emily S. C. Ching

We study the structure of the thermal boundary layer (BL) in Rayleigh-B\'enard convection for Prandtl number ($Pr$) 0.021 by conducting direct numerical simulations in a two-dimensional square box for Rayleigh numbers ($Ra$) up to $10^9$.…

Fluid Dynamics · Physics 2021-01-11 Ambrish Pandey

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…

Results from direct numerical simulations for three dimensional Rayleigh-Benard convection in a cylindrical cell of aspect ratio 1/2 and Pr=0.7 are presented. They span five decades of Ra from $2\times 10^6$ to $2 \times10^{11}$. Good…

Fluid Dynamics · Physics 2011-12-05 Richard J. A. M. Stevens , Roberto Verzicco , Detlef Lohse

Results from direct numerical simulation for three-dimensional Rayleigh-B\'enard convection in samples of aspect ratio $\Gamma=0.23$ and $\Gamma=0.5$ up to Rayleigh number $Ra=2\times10^{12}$ are presented. The broad range of Prandtl…

Fluid Dynamics · Physics 2011-12-05 Richard J. A. M. Stevens , Detlef Lohse , Roberto Verzicco

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…

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 of the properties of the velocity boundary layer in turbulent Rayleigh-B\'{e}nard convection in a cylindrical cell. The measurements were made at Rayleigh numbers $Ra$ in the range…

Fluid Dynamics · Physics 2015-06-11 Ping Wei , Ke-Qing Xia

Statistical properties of turbulent Rayleigh-Benard convection at low Prandtl numbers (Pr), which are typical for liquid metals such as mercury, gallium or liquid sodium, are investigated in high-resolution three-dimensional spectral…

Fluid Dynamics · Physics 2016-09-13 Janet D. Scheel , Joerg Schumacher

Dependence of boundary layer thickness on layer height in laminar and transient regimes is studied for convection from localised heat source with an open surface. The measurements of Nusselt number and characteristic frequency of thermal…

Fluid Dynamics · Physics 2020-08-03 Andrei Sukhanovskii , Anna Evgrafova

Many environmental flows arise due to natural convection at a vertical surface, from flows in buildings to dissolving ice faces at marine-terminating glaciers. We use three-dimensional direct numerical simulations of a vertical channel with…

Fluid Dynamics · Physics 2023-06-22 Christopher J. Howland , Chong Shen Ng , Roberto Verzicco , Detlef Lohse

We simulate numerically Boussinesq convection in non-rotating spherical shells for a fluid with a unity Prandtl number and Rayleigh numbers up to $10^9$. In this geometry, curvature and radial variations of the gravitationnal acceleration…

Fluid Dynamics · Physics 2015-10-28 T. Gastine , J. Wicht , J. M. Aurnou

In turbulent wall sheared thermal convection, there are three different flow regimes, depending on the relative relevance of thermal forcing and wall shear. In this paper we report the results of direct numerical simulations of such sheared…

The logarithmic law of mean temperature profile has been observed in different regions in Rayleigh-B\'enard turbulence. However, how thermal plumes correlate to the log law of temperature and how the velocity profile changes with pressure…

Fluid Dynamics · Physics 2019-10-08 Hong-Yue Zou , Wen-Feng Zhou , Xi Chen , Yun Bao , Jun Chen , Zhen-Su She

The effect of the wind of Rayleigh-Benard convection on the boundary layers is studied by direct numerical simulation of an L/H=4 aspect-ratio domain with periodic side boundary conditions for Ra={10^5, 10^6, 10^7} and Pr=1. It is shown…

Fluid Dynamics · Physics 2008-05-23 Maarten van Reeuwijk , Harm J. J. Jonker , Kemo Hanjalic

We compute fully local boundary layer scales in three-dimensional turbulent Rayleigh-Benard convection. These scales are directly connected to the highly intermittent fluctuations of the fluxes of momentum and heat at the isothermal top and…

Fluid Dynamics · Physics 2014-11-04 Janet D. Scheel , Joerg Schumacher

We perform direct numerical simulations of rotating Rayleigh--B\'enard convection of fluids with low ($Pr=0.1$) and high ($Pr=5$) Prandtl numbers in a horizontally periodic layer with no-slip top and bottom boundaries. At both Prandtl…

We numerically investigate the structures of the near-plate temperature profiles close to the bottom and top plates of turbulent Rayleigh-B\'{e}nard flow in a cylindrical sample at Rayleigh numbers Ra=10^8 to Ra=2\times10^{12} and Prandtl…

The objective of the present study is to provide a numerical database of thermal boundary layers and to contribute to the understanding of the dynamics of passive scalars at different Prandtl numbers. In this regard, a direct numerical…

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