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相关论文: Aspect ratio dependence of heat transport by turbu…

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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

We numerically investigate turbulent Rayleigh-B\'enard convection within two immiscible fluid layers, aiming to understand how the layer thickness and fluid properties affect the heat transfer (characterized by the Nusselt number $Nu$) in…

流体动力学 · 物理学 2022-05-24 Hao-Ran Liu , Kai Leong Chong , Rui Yang , Roberto Verzicco , Detlef Lohse

Measurements of heat transport, as expressed by the Nusselt number $Nu$, are reported for turbulent Rayleigh-B\'enard convection of water containing up to 120 ppm by weight of poly-[ethylene oxide] with a molecular weight of $4\times10^6$…

流体动力学 · 物理学 2015-05-14 Guenter Ahlers , Alexei Nikolaenko

We use highly resolved numerical simulations to study turbulent Rayleigh-B\'enard convection in a cell with sinusoidally rough upper and lower surfaces in two dimensions for $Pr = 1$ and $Ra = \left[4 \times 10^6, 3 \times 10^9\right]$. By…

流体动力学 · 物理学 2017-03-08 Srikanth Toppaladoddi , Sauro Succi , John S. Wettlaufer

Steady two-dimensional Rayleigh--B\'enard convection between stress-free isothermal boundaries is studied via numerical computations. We explore properties of steady convective rolls with aspect ratios $\pi/5\le\Gamma\le4\pi$, where…

流体动力学 · 物理学 2021-06-30 Baole Wen , David Goluskin , Matthew LeDuc , Gregory P. Chini , Charles R. Doering

Temperature and velocity oscillations have been found in a rectangular Rayleigh-B\'{e}nard convection cell, in which one large scale convection roll exists. At $Ra=8.9 \times 10^{11}$ and $Pr=4$, temperature oscillation can be observed in…

流体动力学 · 物理学 2009-11-13 Sheng-Qi Zhou , Chao Sun , Ke-Qing Xia

We present an experimental study of Rayleigh-B\'enard convection using liquid metal alloy gallium-indium-tin as the working fluid with a Prandtl number of $Pr=0.029$. The flow state and the heat transport were measured in a Rayleigh number…

流体动力学 · 物理学 2023-08-01 Lei Ren , Xin Tao , Lu Zhang , Ming-Jiu Ni , Ke-Qing Xia , Yi-Chao Xie

We numerically investigate the radial dependence of the velocity and temperature fluctuations and of the time-averaged heat flux $\bar{j}(r)$ in a cylindrical Rayleigh-B\'enard cell with aspect ratio \Gamma=1 for Rayleigh numbers Ra between…

We perform a numerical study of the heat transfer and flow structure of Rayleigh-B\'enard (RB) convection in (in most cases regular) porous media, which are comprised of circular, solid obstacles located on a square lattice. This study is…

We report measurements of properties of turbulent thermal convection of a fluid with a Prandtl number $\Pra=4.38$ in a cylindrical cell with an aspect ratio $\Gamma=0.50$. The rotational symmetry was broken by a small tilt of the sample…

流体动力学 · 物理学 2015-06-05 Stephan Weiss , Guenter Ahlers

The Rayleigh number $Ra$ dependence of the Nusselt number $Nu$ in turbulent Rayleigh--B\'enard convection is numerically investigated for a moderate and low Prandtl number, $Pr=0.7$ and $0.021$, respectively. Here we specifically address…

流体动力学 · 物理学 2019-06-18 Marten Klein , Heiko Schmidt

In turbulent Rayleigh-B\'{e}nard (RB) convection, a transition to the so-called ultimate regime, in which the boundary layers (BL) are of turbulent type, has been postulated. Indeed, at very large Rayleigh number $Ra \approx…

流体动力学 · 物理学 2018-08-15 Dominik Krug , Xiaojue Zhu , Daniel Chung , Ivan Marusic , Roberto Verzicco , Detlef Lohse

Flows at planetary scales are generally driven by buoyancy and influenced by rotation. Rotating Rayleigh-B\'enard convection (RRBC) is a practical and simple model that can be used to describe these systems. In RRBC, thermally induced…

流体动力学 · 物理学 2025-12-01 Hannah M. Clercx , Rudie P. J. Kunnen

We investigate states of rapidly rotating Rayleigh-B\'enard convection in a cylindrical cell over a range of Rayleigh number $3\times10^5\leq Ra \leq 5\times10^{9}$ and Ekman number $10^{-6} \leq Ek \leq 10^{-4}$ for Prandtl number $Pr =…

流体动力学 · 物理学 2024-04-16 Xuan Zhang , Philipp Reiter , Olga Shishkina , Robert E. Ecke

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…

流体动力学 · 物理学 2019-07-05 Michael MacDonald , Nicholas Hutchins , Detlef Lohse , Daniel Chung

We report on direct numerical simulations of two-dimensional, horizontally periodic Rayleigh-B\'enard convection, focusing on its ability to drive large-scale horizontal flow that is vertically sheared. For the Prandtl numbers ($Pr$)…

流体动力学 · 物理学 2015-11-20 David Goluskin , Hans Johnston , Glenn R. Flierl , Edward A. Spiegel

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

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 perform direct numerical simulations of natural convection in a differentially heated cavity over Rayleigh number $Ra=10^6$--$10^8$ at Prandtl number $Pr=0.7$, systematically varying the aspect ratio over $0.1 \leq \Gamma \leq 60$.…

流体动力学 · 物理学 2026-05-06 Krishan Chand , Michael Quan , Haoxiang Luo

We present a theory to describe the Nusselt number ($Nu$), corresponding to the heat or mass flux, as a function of the Rayleigh--Darcy number ($Ra$), the ratio of buoyant driving force over diffusive dissipation, in convective porous media…

流体动力学 · 物理学 2024-11-20 Xiaojue Zhu , Yifeng Fu , Marco De Paoli