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We discuss two aspects of turbulent Rayleigh-B\'{e}nard convection (RBC) on the basis of high-resolution direct numerical simulations in a unique setting; a closed cylindrical cell of aspect ratio of one. First, we present a comprehensive…

Fluid Dynamics · Physics 2017-11-29 Janet D. Scheel , Jörg Schumacher

Direct numerical simulations have been performed for turbulent thermal convection between horizontal no-slip, permeable walls with a distance $H$ and a constant temperature difference $\Delta T$ at the Rayleigh number…

Fluid Dynamics · Physics 2020-04-21 Koki Kawano , Shingo Motoki , Masaki Shimizu , Genta Kawahara

Rotation, which stabilizes flow, can enhance the heat transfer in Rayleigh-B\'enard convection (RBC) through Ekman pumping. In this Letter, we present the results of our direct numerical simulations of rotating RBC, providing a…

Fluid Dynamics · Physics 2024-01-18 Mohammad Anas , Pranav Joshi

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 $0.1 \leq \Gamma \leq 60$.…

Fluid Dynamics · Physics 2026-05-06 Krishan Chand , Michael Quan , Haoxiang Luo

The phenomenon of irregular cessation and subsequent reversal of the large-scale circulation in turbulent Rayleigh-B\'enard convection is theoretically analysed. The force and thermal balance on a single plume detached from the thermal…

Chaotic Dynamics · Physics 2009-11-10 Francisco Fontenele Araujo , S. Grossmann , D. Lohse

Recent investigations show that steady solutions share many features with turbulent Rayleigh--B\'enard convection (RBC) and form the state space skeleton of turbulent dynamics. Previous computations of steady roll solutions in…

Fluid Dynamics · Physics 2022-12-13 Alexander Takla , Baole Wen

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

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…

Fluid Dynamics · Physics 2019-12-12 Ao Xu , Le Shi , Heng-Dong Xi

We present observations of oscillations in the shape of the temperature profile of the large-scale circulation (LSC) of turbulent Rayleigh-B{\'e}nard convection. Temperature measurements are broken down into Fourier moments as a function of…

Fluid Dynamics · Physics 2020-06-22 Dandan Ji , Eric Brown

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 present a numerical study of the reversals and reorientations of the large scale circulation (LSC) of convective fluid in a cylindrical container of aspect ratio one. We take Prandtl number to be 0.7 and Rayleigh numbers in the range…

Fluid Dynamics · Physics 2011-02-14 Pankaj Kumar Mishra , Arnab De , Mahendra K. Verma , V. Eswaran

The progress in our understanding of several aspects of turbulent Rayleigh-Benard convection is reviewed. The focus is on the question of how the Nusselt number and the Reynolds number depend on the Rayleigh number Ra and the Prandtl number…

Fluid Dynamics · Physics 2015-05-13 Guenter Ahlers , Siegfried Grossmann , Detlef Lohse

We present a direct numerical simulation to investigate the dynamics and statistics of reorientations of large-scale circulation (LSC) in turbulent rotating Rayleigh-B\'{e}nard convection (RRBC) for air ($Pr=0.7$) contained in a cylindrical…

Fluid Dynamics · Physics 2019-06-26 Venugopal T Vishnu , Arnab Kumar De , Pankaj Kumar Mishra

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…

Fluid Dynamics · Physics 2022-05-24 Hao-Ran Liu , Kai Leong Chong , Rui Yang , Roberto Verzicco , Detlef Lohse

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…

Fluid Dynamics · Physics 2018-08-15 Dominik Krug , Xiaojue Zhu , Daniel Chung , Ivan Marusic , Roberto Verzicco , Detlef Lohse

A detailed study of the Rayleigh-B\'enard convection in two-dimensions with free-slip boundaries is presented. Pseudo-spectral method has been used to numerically solve the system for Rayleigh number up to $3.3 \times 10^7$. The system…

Fluid Dynamics · Physics 2009-04-21 Supriyo Paul , Pankaj K. Mishra , Mahendra K. Verma , Krishna Kumar

In thermal convection, roughness is often used as a means to enhance heat transport, expressed in Nusselt number. Yet there is no consensus on whether the Nusselt vs. Rayleigh number scaling exponent ($\mathrm{Nu} \sim \mathrm{Ra}^\beta$)…

Fluid Dynamics · Physics 2017-10-18 Xiaojue Zhu , Richard J. A. M. Stevens , Roberto Verzicco , Detlef Lohse

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

We study the effects of Prandtl number $Pr$ and Rayleigh number $Ra$ in two-dimensional Rayleigh-B\'enard convection without boundaries, i.e. with periodic boundary conditions. In the limits of $Pr \to 0$ and $\infty$, we find that the…

Fluid Dynamics · Physics 2023-12-27 Philip Winchester , Vassilios Dallas , Peter D. Howell

We have found a multi-scale steady solution of the Boussinesq equations for Rayleigh-B\'enard convection in a three-dimensional periodic domain between horizontal plates with a constant temperature difference by using a homotopy from the…

Fluid Dynamics · Physics 2020-04-16 Shingo Motoki , Genta Kawahara , Masaki Shimizu