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相关论文: The onset of low Prandtl number thermal convection…

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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

We report a new thermal boundary layer equation for turbulent Rayleigh-Benard convection for Prandtl number Pr>1 that takes into account the effect of turbulent fluctuations. These fluctuations are neglected in existing equations, which are…

流体动力学 · 物理学 2015-06-23 Olga Shishkina , Susanne Horn , Sebastian Wagner , Emily S. C. Ching

Results on the Prandtl-Blasius type kinetic and thermal boundary layer thicknesses in turbulent Rayleigh-B\'enard convection in a broad range of Prandtl numbers are presented. By solving the laminar Prandtl-Blasius boundary layer equations,…

流体动力学 · 物理学 2015-03-19 Olga Shishkina , Richard J. A. M. Stevens , Siegfried Grossmann , Detlef Lohse

Convection is the predominant mechanism by which energy and angular momentum are transported in the outer portion of the Sun. The resulting overturning motions are also the primary energy source for the solar magnetic field. An accurate…

太阳与恒星天体物理 · 物理学 2018-03-26 Ryan J. Orvedahl , Michael A. Calkins , Nicholas A. Featherstone , Bradley W. Hindman

This paper reports on a theoretical analysis of the rich variety of spatio-temporal patterns observed recently in inclined layer convection at medium Prandtl number when varying the inclination angle $\gamma$ and the Rayleigh number $R$.…

Motivated by understanding the dynamics of stellar and planetary interiors, we have performed a set of direct numerical simulations of Boussinesq convection in a rotating full sphere. The domain is internally heated with fixed temperature…

流体动力学 · 物理学 2021-05-05 Yufeng Lin , Andrew Jackson

A Rayleigh-B\'enard cell has been designed to explore the Prandtl (Pr) dependence of turbulent convection in the cross-over range $0.7<Pr<21$ and for the full range of soft and hard turbulences, up to Rayleigh number $Ra\simeq 10^{11}$. The…

凝聚态物理 · 物理学 2009-11-10 P. -E. Roche , B. Castaing , B. Chabaud , B. Hebral

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…

流体动力学 · 物理学 2011-12-05 Richard J. A. M. Stevens , Detlef Lohse , Roberto Verzicco

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…

流体动力学 · 物理学 2023-12-27 Philip Winchester , Vassilios Dallas , Peter D. Howell

We present three results on stability of rolls in Boussinesq convection in a plane horizontal layer with rigid boundaries that is rotating about an inclined axis with the angular velocity $\Omega=(\Omega_1,\Omega_2,\Omega_3)$. i. We call…

流体动力学 · 物理学 2023-12-27 Olga Podvigina

Large-scale patterns, which are well-known from the spiral defect chaos regime of thermal convection at Rayleigh numbers $Ra < 10^4$, continue to exist in three-dimensional numerical simulations of turbulent Rayleigh-B\'{e}nard convection…

流体动力学 · 物理学 2016-12-30 Mohammad S. Emran , Jörg Schumacher

A series of numerical simulations of thermal convection of Boussinesq fluid with infinite Prandtl number, with Rayleigh number $10^7$, and with the strongly temperature- and depth- dependent viscosity in a three-dimensional spherical shell…

地球物理 · 物理学 2015-06-26 Masaki Yoshida , Akira Kageyama

We present the results of an ensemble of SPH simulations that follow the evolution of prestellar cores for $0.2\,{\rm Myr}$. All the cores have the same mass, and start with the same radius, density profile, thermal and turbulent energy.…

太阳与恒星天体物理 · 物理学 2015-06-23 O. Lomax , A. P. Whitworth , D. A. Hubber

We extend the notion of a shell model to stratified systems, and propose one that represents stratified, nonmagnetic, nonrotating convection at low Mach number. Motivated by profiles of background stratification that support convection in…

太阳与恒星天体物理 · 物理学 2022-06-13 Kishore Gopalakrishnan , Nishant K. Singh

Rayleigh-B\'enard convection in rotating spherical shells can be considered as a simplified analogue of many astrophysical and geophysical fluid flows. Here, we use three-dimensional direct numerical simulations to study this physical…

流体动力学 · 物理学 2016-11-23 T. Gastine , J. Wicht , J. Aubert

We report pore-scale statistical properties of temperature and thermal energy dissipation rate in a two-dimensional porous Rayleigh-B\'enard (RB) cell. High-resolution direct numerical simulations were carried out for the fixed Rayleigh…

流体动力学 · 物理学 2023-09-20 Ao Xu , Ben-Rui Xu , Heng-Dong Xi

We study the formation and evolution of a convective layer when a stably-stratified fluid with a composition gradient is cooled from above. We perform a series of 2D simulations using the Bousinessq approximation with Prandtl number ranging…

太阳与恒星天体物理 · 物理学 2023-11-08 J. R. Fuentes , A. Cumming

Inclined turbulent thermal convection by large Rayleigh numbers in extremely small-Prandtl-number fluids is studied based on results of both, measurements and high-resolution numerical simulations. The Prandtl number $Pr\approx0.0093$…

In this manuscript, it is analysed the onset and evolution of natural convection of an incompressible fluid between spherical shells. The shells are kept at a fixed temperature difference and aspect ratio, and the Rayleigh-Benard convection…

流体动力学 · 物理学 2023-09-07 Luca Santelli , Guiquan Wang , Richard J. A. M. Stevens , Roberto Verzicco

We use 123 three dimensional direct numerical simulations to study fingering convection in non-rotating spherical shells. We investigate the scaling behaviour of the flow lengthscale, the non-dimensional heat and compositional fluxes $Nu$…

流体动力学 · 物理学 2024-04-26 T. Tassin , T. Gastine , A. Fournier