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Related papers: Scaling relations in large-Prandtl-number natural …

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The Rayleigh-Benard theory by Grossmann and Lohse [J. Fluid Mech. 407, 27 (2000)] is extended towards very large Prandtl numbers Pr. The Nusselt number Nu is found here to be independent of Pr. However, for fixed Rayleigh numbers Ra>…

Chaotic Dynamics · Physics 2009-10-31 Siegfried Grossmann , Detlef Lohse

A systematic theory for the scaling of the Nusselt number $Nu$ and of the Reynolds number $Re$ in strong Rayleigh-Benard convection is suggested and shown to be compatible with recent experiments. It assumes a coherent large scale…

chao-dyn · Physics 2017-05-17 Siegfried Grossmann , Detlef Lohse

We study the scaling properties of heat transfer $Nu$ in turbulent thermal convection at large Prandtl number $Pr$ using a quasi-linear theory. We show that two regimes arise, depending on the Reynolds number $Re$. At low Reynolds number,…

Chaotic Dynamics · Physics 2015-05-28 B. Dubrulle

We report on a numerical study of turbulent convection driven by a combination of internal heat sources and sinks. Motivated by a recent experimental realisation (Lepot et al. 2018), we focus on the situation where the cooling is uniform,…

Fluid Dynamics · Physics 2020-10-21 Benjamin Miquel , Vincent Bouillaut , Sebastien Aumaitre , Basile Gallet

The Rayleigh (Ra) and Prandtl (Pr) number scaling of the Nusselt number Nu, the Reynolds number Re, the temperature fluctuations, and the kinetic and thermal dissipation rates is studied for (numerical) homogeneous Rayleigh-Benard…

Chaotic Dynamics · Physics 2007-05-23 Enrico Calzavarini , Detlef Lohse , Federico Toschi , Raffaele Tripiccione

We propose a phenomenological model for thermal convection at high Rayleigh numbers. It hypothesizes existence of a high-Reynolds-number turbulent boundary layer near each horizontal plate, which is shown to be convective. The convective…

Fluid Dynamics · Physics 2024-03-27 Chenning Tong

The unifying theory of scaling in thermal convection (Grossmann & Lohse (2000)) (henceforth the GL theory) suggests that there are no pure power laws for the Nusselt and Reynolds numbers as function of the Rayleigh and Prandtl numbers in…

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 provide scaling relations for the Nusselt number $Nu$ and the friction coefficient $C_{S}$ in sheared Rayleigh-B\'enard convection, i.e., in Rayleigh-B\'enard flow with Couette or Poiseuille type shear forcing, by extending the Grossmann…

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…

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

A solvable turbulent model is used to predict both the structure of the boundary layer and the scaling laws in thermal convection. The transport of heat depends on the interplay between the thermal, viscous and integral scales of…

Fluid Dynamics · Physics 2015-05-28 B. Dubrulle

We report on the transition between two regimes of heat transport in a radiatively driven convection experiment, where a fluid gets heated up within a tunable heating length $\ell$ in the vicinity of the bottom of the tank. The first regime…

Fluid Dynamics · Physics 2020-10-22 V. Bouillaut , S. Lepot , S. Aumaître , B. Gallet

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…

Fluid Dynamics · Physics 2024-11-20 Xiaojue Zhu , Yifeng Fu , Marco De Paoli

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…

Previous numerical studies on homogeneous Rayleigh-B\'enard convection, which is Rayleigh-B\'enard convection (RBC) without walls, and therefore without boundary layers, have revealed a scaling regime that is consistent with theoretical…

Fluid Dynamics · Physics 2018-06-22 Chong Shen Ng , Andrew Ooi , Detlef Lohse , Daniel Chung

Vertical convection is investigated using direct numerical simulations over a wide range of Rayleigh numbers $10^7\le Ra\le10^{14}$ with fixed Prandtl number $Pr=10$, in a two-dimensional convection cell with unit aspect ratio. It is found…

Fluid Dynamics · Physics 2021-05-05 Qi Wang , Hao-Ran Liu , Roberto Verzicco , Olga Shishkina , Detlef Lohse

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 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

Under the limit of infinite Prandtl number, we derive analytical expressions for the large-scale quantities, e.g., P\'{e}clet number Pe, Nusselt number Nu, and rms value of the temperature fluctuations $\theta_\mathrm{rms}$. We complement…

Fluid Dynamics · Physics 2014-02-17 Ambrish Pandey , Mahendra K. Verma , Pankaj K. Mishra
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