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Related papers: Optimal heat transport in rotating Rayleigh-B\'{e}…

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Rapidly rotating Rayleigh-B\'enard convection is studied by combining results from direct numerical simulations (DNS), laboratory experiments and asymptotic modeling. The asymptotic theory is shown to provide a good description of the bulk…

Fluid Dynamics · Physics 2015-06-23 S. Stellmach , M. Lischper , K. Julien , G. Vasil , J. S. Cheng , A. Ribeiro , E. M. King , J. M. Aurnou

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

Turbulent thermal convection is characterized by the formation of large-scale structures and strong spatial inhomogeneity. This work addresses the relative heat transport contributions of the large-scale plume ejecting versus plume…

Fluid Dynamics · Physics 2021-04-09 Philipp Reiter , Olga Shishkina , Detlef Lohse , Dominik Krug

We investigate the influence of the thermal properties of the boundaries in turbulent Rayleigh-B\'enard convection on analytical upper bounds on convective heat transport. We model imperfectly conducting bounding plates in two ways: using…

Fluid Dynamics · Physics 2010-08-17 Ralf W. Wittenberg

We present a numerical study of vorticity production and transport in the two-dimensional Rayleigh-B\'enard (RB) convection. Direct numerical simulations are carried out in the Rayleigh number ($Ra$) range $10^{5}\le Ra \le 10^{6}$, the…

Fluid Dynamics · Physics 2022-01-20 Ao Xu , Ben-Rui Xu , Li-Sheng Jiang , Heng-Dong Xi

Penetrative turbulent Rayleigh-B\'enard convection which depends on the density maximum of water near $4^\circ\rm{C}$ is studied using two-dimensional (2D) and three-dimensional (3D) direct numerical simulations (DNS). The working fluid is…

Fluid Dynamics · Physics 2019-06-26 Qi Wang , Quan Zhou , Zhen-Hua Wan , De-Jun Sun

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…

Fluid Dynamics · Physics 2020-11-25 Srikanth Toppaladoddi , Andrew J. Wells , Charles R. Doering , John S. Wettlaufer

The dynamics of heat transfer in a model system of Rayleigh-B\'enard (RB) convection reduced to its essential, here dubbed Burgers-Rayleigh-B\'enard (BRB), is studied. The system is spatially one-dimensional, the flow field is compressible…

Fluid Dynamics · Physics 2023-07-04 Enrico Calzavarini , Silvia C. Hirata

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 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 study numerically the melting of a horizontal layer of a pure solid above a convecting layer of its fluid rotating about the vertical axis. In the rotating regime studied here, with Rayleigh numbers of order $10^7$, convection takes the…

Fluid Dynamics · Physics 2021-04-13 S. Ravichandran , J. S. Wettlaufer

Recently, in Zhang et al. (2020), it was found that in rapidly rotating turbulent Rayleigh-B\'enard convection (RBC) in slender cylindrical containers (with diameter-to-height aspect ratio $\Gamma=1/2$) filled with a small-Prandtl-number…

Fluid Dynamics · Physics 2021-07-01 Xuan Zhang , Robert E. Ecke , Olga Shishkina

Steady but generally unstable solutions of the 2D Boussinesq equations are obtained for no-slip boundary conditions and Prandtl number 7. The primary solution that bifurcates from the conduction state at Rayleigh number $Ra \approx 1708$…

Fluid Dynamics · Physics 2015-06-11 Fabian Waleffe , Anakewit Boonkasame , Leslie M. Smith

Bounds on heat transfer have been the subject of previous studies concerning convection in the Boussinesq approximation: in the Rayleigh-B\'enard configuration, the first result obtained by \cite{howard63} states that $Nu < (3/64 \…

Fluid Dynamics · Physics 2024-03-08 T. Alboussière , Y. Ricard , S. Labrosse

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

Boiling is an extremely effective way to promote heat transfer from a hot surface to a liquid due to several mechanisms many of which are not understood in quantitative detail. An important component of the overall process is that the…

We present high-resolution numerical investigations of heat transport by two-dimensional (2D) turbulent Rayleigh-B\'{e}nard (RB) convection over the Rayleigh number range $10^8 \leqslant Ra\leqslant 10^{10}$ and the Prandtl number range…

Fluid Dynamics · Physics 2015-06-17 Yong-Xiang Huang , Quan Zhou

Direct Numerical Simulations of turbulent convection in a large aspect-ratio box are carried out in the range of Rayleigh number $7 \times 10^4 \le Ra \le 2 \times 10^6$ at Prandtl number Pr=0.71. A strong correlation between the vertical…

Fluid Dynamics · Physics 2017-08-09 Arnab K. De , Vinayak Eswaran , Pankaj K. Mishra

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)].…

We report measurements of turbulent heat-transport in samples of ethane (C$_2$H$_6$) heated from below while the applied temperature difference $\Delta T$ straddled the liquid-vapor co-existance curve $T_\phi(P)$. When the sample top…

Fluid Dynamics · Physics 2009-11-13 Jin-Qiang Zhong , Denis Funfschilling , Guenter Ahlers