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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…

流体动力学 · 物理学 2012-09-04 Nan Shi , Mohammad S. Emran , Joerg Schumacher

Results on the Prandtl-Blasius type kinetic and thermal boundary layer thicknesses in turbulent Rayleigh-B\'enard convection in a broad range of Prandtl numbers are presented. By solving the laminar Prandtl-Blasius boundary layer equations,…

流体动力学 · 物理学 2015-03-19 Olga Shishkina , Richard J. A. M. Stevens , Siegfried Grossmann , 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…

流体动力学 · 物理学 2011-12-05 Richard J. A. M. Stevens , Detlef Lohse , Roberto Verzicco

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 $10^9$.…

流体动力学 · 物理学 2021-01-11 Ambrish Pandey

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…

流体动力学 · 物理学 2015-10-28 T. Gastine , J. Wicht , J. M. Aurnou

We present three-dimensional direct numerical simulations of turbulent Rayleigh-B\'enard convection in a closed rectangular box whose width $L_y$ and length $L_x$ are 0.8 and 2.4 times the height $H$, respectively. The Rayleigh number $Ra$…

流体动力学 · 物理学 2026-05-05 Ambrish Pandey , Jörg Schumacher , Matteo Parsani , Katepalli R. Sreenivasan

We prove the first rigorous bound on the heat transfer for three-dimensional Rayleigh-B\'enard convection of finite-Prandtl-number fluids between free-slip boundaries with an imposed heat flux. Using the auxiliary functional method with a…

流体动力学 · 物理学 2018-04-11 Giovanni Fantuzzi

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 =…

流体动力学 · 物理学 2023-09-15 Theo Käufer , Philipp P. Vieweg , Jörg Schumacher , Christian Cierpka

Rigorous upper limits on the vertical heat transport in two dimensional Rayleigh-Benard convection between stress-free isothermal boundaries are derived from the Boussinesq approximation of the Navier-Stokes equations. The Nusselt number Nu…

流体动力学 · 物理学 2015-05-27 Jared P. Whitehead , Charles R. Doering

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 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 use well resolved numerical simulations with the Lattice Boltzmann Method to study Rayleigh-B\'enard convection in cells with a fractal boundary in two dimensions for $Pr = 1$ and $Ra \in \left[10^7, 10^{10}\right]$. The fractal…

流体动力学 · 物理学 2020-11-25 Srikanth Toppaladoddi , Andrew J. Wells , Charles R. Doering , John S. Wettlaufer

The possible transition to the so-called ultimate regime, wherein both the bulk and the boundary layers are turbulent, has been an outstanding issue in thermal convection, since the seminal work by Kraichnan [Phys. Fluids 5, 1374 (1962)].…

流体动力学 · 物理学 2018-04-12 Xiaojue Zhu , Varghese Mathai , Richard J. A. M. Stevens , Roberto Verzicco , Detlef Lohse

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…

流体动力学 · 物理学 2019-01-15 Benjamin Favier , Jhaswantsing Purseed , Laurent Duchemin

We report a numerical study of horizontal convection (HC) at Prandtl number $Pr = 1$, with both no-slip and free-slip boundary conditions. We obtain 2D and 3D solutions and determine the relation between the Rayleigh number $Ra$ and the…

流体动力学 · 物理学 2023-06-09 Navid C. Constantinou , Cesar B. Rocha , Stefan G. Llewellyn Smith , William R. Young

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…

流体动力学 · 物理学 2016-12-30 Jörg Schumacher , Vinodh Bandaru , Ambrish Pandey , Janet D. Scheel

We study penetrative convection of a fluid confined between two horizontal plates, the temperatures of which are such that a temperature of maximum density lies between them. The range of Rayleigh numbers studied is $Ra = \left[10^6, 10^8…

流体动力学 · 物理学 2019-09-10 Srikanth Toppaladoddi , J. S. Wettlaufer

We report the statistical properties of temperature and thermal energy dissipation rate in low-Prandtl number turbulent Rayleigh-B\'enard convection. High resolution two-dimensional direct numerical simulations were carried out for the…

流体动力学 · 物理学 2019-12-12 Ao Xu , Le Shi , Heng-Dong Xi

We are concerned with infinite Prandtl number Rayleigh--B\'enard convection with Navier-slip boundary conditions. The goal of this work is to estimate the average upward heat flux measured by the nondimensional Nusselt number $Nu$ in terms…

偏微分方程分析 · 数学 2026-03-24 Christian Seis

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…

流体动力学 · 物理学 2012-09-28 Ronald du Puits , Johannes Rilk , Christian Resagk , André Thess
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