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Related papers: Convectively driven shear and decreased heat flux

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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

We numerically simulate three-dimensional Rayleigh-B\'enard convection, the flow in a fluid layer heated from below and cooled from above, with inhomogeneous temperature boundary conditions to explore two distinct regimes described in…

Fluid Dynamics · Physics 2020-10-28 Rodolfo Ostilla-Monico , Amit Amritkar

We study numerically the dependence of heat transport on the maximum velocity and shear rate of physical circulating flows, which are prescribed to have the key characteristics of the large-scale mean flow observed in turbulent convection.…

Chaotic Dynamics · Physics 2009-11-07 Emily S. C. Ching , K. M. Pang

In Rayleigh-B\'enard convection, it has been found that the amount of heat passing through the fluid has a power law dependence on the imposed temperature difference. Modifying this dependence, either enhancing or reducing the heat transfer…

Fluid Dynamics · Physics 2022-10-14 Jinzi Mac Huang , Jun Zhang

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…

In this paper we carry out a numerical investigation of forced convection heat transfer from a heated elliptical cylinder in a uniform free stream with angle of inclination $\theta^{\circ}$. Numerical simulations were carried out for $10…

Fluid Dynamics · Physics 2023-08-21 Raghav Singhal , Sailen Dutta , Jiten C. Kalita

Penetrative turbulence, which occurs in a convectively unstable fluid layer and penetrates into an adjacent, originally stably stratified layer, is numerically and theoretically analyzed. We chose the most relevant example, namely thermally…

Fluid Dynamics · Physics 2021-06-30 Qi Wang , Philipp Reiter , Detlef Lohse , Olga Shishkina

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

To understand turbulent convection at very high Rayleigh numbers typical of natural phenomena, computational studies in slender cells are an option if the needed resources have to be optimized within available limits. However, the…

We investigate the onset of convective instability and subsequent transitions near it in Rayleigh-B\'enard convection (RBC) of electrically conducting low Prandtl-number (Pr) fluids in the simultaneous presence of rotation about the…

Fluid Dynamics · Physics 2018-12-18 Manojit Ghosh , Paromita Ghosh , Yada Nandukumar , Pinaki Pal

$SF_6$ in the vicinity of its critical point was used to study turbulent convection up to exceptionally high Rayleigh numbers, $Ra$, (up to $5\cdot 10^{14}$) and to verify for the first time the generalized scaling laws for the heat…

chao-dyn · Physics 2009-10-31 Sh. Ashkenazi , V. Steinberg

We report flow measurements in rotating Rayleigh--B\'enard convection in the rotationally-constrained geostrophic regime. We apply stereoscopic particle image velocimetry to measure the three components of velocity in a horizontal…

The effects of a vertical static magnetic field on the flow structure and global transport properties of momentum and heat in liquid metal Rayleigh-B\'enard convection are investigated. Experiments are conducted in a cylindrical convection…

Fluid Dynamics · Physics 2020-05-13 Till Zürner , Felix Schindler , Tobias Vogt , Sven Eckert , Jörg Schumacher

Rayleigh-B\'{e}nard convection is studied and quantitative comparisons are made, where possible, between theory and experiment by performing numerical simulations of the Boussinesq equations for a variety of experimentally realistic…

Pattern Formation and Solitons · Physics 2009-11-07 M. R. Paul , K. -H. Chiam , M. C. Cross , P. F. Fischer , H. S. Greenside

Rayleigh-B\'enard cells are one of the simplest systems to explore the laws of natural convection in the highly turbulent limit. However, at very high Rayleigh numbers (Ra > 1E12) and for Prandtl numbers of order one, experiments fall into…

Fluid Dynamics · Physics 2012-02-14 Philippe-E. Roche , Frédéric Gauthier , Robert Kaiser , Julien Salort

Rayleigh-B\'enard convection is numerically simulated in two- and three-dimensions using a recently developed two-component lattice Boltzmann equation (LBE) method. The density field of the second component, which evolves according to the…

comp-gas · Physics 2016-08-31 Xiaowen Shan

It has been previously shown (Phys. Rev. E 66, 066305, 2002) that a non-rotating turbulent convection with nonuniform large-scale flows contributes to the turbulent heat flux. As a result, the turbulent heat flux depends explicitly not only…

Fluid Dynamics · Physics 2024-04-19 G. Orian , A. Asulin , E. Tkachenko , N. Kleeorin , A. Levy , I. Rogachevskii

The coarsening and wavenumber selection of striped states growing from random initial conditions are studied in a non-relaxational, spatially extended, and far-from-equilibrium system by performing large-scale numerical simulations of…

Pattern Formation and Solitons · Physics 2009-11-10 M. R. Paul , K-H. Chiam , M. C. Cross , P. F. Fischer

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 studied the transport and deposition behaviour of point particles in Rayleigh-B\'enard convection cells subjected to Couette-type wall shear. Direct numerical simulations (DNSs) are performed for Rayleigh number ($Ra$) in the range $10^7…

Fluid Dynamics · Physics 2024-11-20 Ao Xu , Ben-Rui Xu , Heng-Dong Xi