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Rayleigh-B\'{e}nard convection in horizontal layers of binary fluid mixtures heated from below with realistic horizontal boundary conditions is studied theoretically using multi-mode Galerkin expansions. For positive separation ratios the…

patt-sol · Physics 2017-05-17 B. Huke , M. Lücke , P. Büchel , Ch. Jung

Here we summarize the results from our direct numerical simulations (DNS) and experimental measurements on rotating Rayleigh-B\'enard (RB) convection. Our experiments and simulations are performed in cylindrical samples with an aspect ratio…

Fluid Dynamics · Physics 2013-06-21 Richard J. A. M. Stevens , Herman Clercx , Detlef Lohse

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

We present the results of direct numerical simulations of flow patterns in a low-Prandtl-number ($Pr = 0.1$) fluid above the onset of oscillatory convection in a Rayleigh-B\'{e}nard system rotating uniformly about a vertical axis.…

Fluid Dynamics · Physics 2014-02-19 Hirdesh K. Pharasi , Krishna Kumar

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

An investigation of the effect of a destabilizing cross-stream temperature gradient on the transient growth phenomenon of plane Poiseuille flow and plane Couette flow is presented. Only the streamwise-uniform and nearly streamwise-uniform…

Fluid Dynamics · Physics 2016-01-29 J. John Soundar Jerome , Jean-Marc Chomaz , Patrick Huerre

If a fluid flow is driven by a weak Gaussian random force, the nonlinearity in the Navier-Stokes equations is negligibly small and the resulting velocity field obeys Gaussian statistics. Nonlinear effects become important as the driving…

Fluid Dynamics · Physics 2018-10-01 Jörg Schumacher , Ambrish Pandey , Victor Yakhot , Katepalli R. Sreenivasan

Rapidly rotating Rayleigh-B\'enard convection admits a class of exact steady single-mode solutions describing high-amplitude convection cells. Using a matched asymptotic analysis in the high-Rayleigh-number limit, we obtain a rigorous…

Fluid Dynamics · Physics 2026-05-08 Gabriel Hadjerci , Shingo Motoki , Genta Kawahara

Natural convection is ubiquitous throughout the physical sciences and engineering, yet many of its important properties remain elusive. To study convection in a novel context, we derive and solve a quasilinear form of the Rayleigh-B\'enard…

Fluid Dynamics · Physics 2024-02-29 Liam O'Connor , Daniel Lecoanet , Evan H. Anders

Turbulent Rayleigh-B\'enard convection displays a large-scale order in the form of rolls and cells on lengths larger than the layer height once the fluctuations of temperature and velocity are removed. These turbulent superstructures are…

Fluid Dynamics · Physics 2018-05-30 Ambrish Pandey , Janet D. Scheel , Jörg Schumacher

Rigorous upper limits on the vertical heat transport in two dimensional Rayleigh-Benard convection between stress-free isothermal boundaries are derived from the Boussinesq approximation of the Navier-Stokes equations. The Nusselt number Nu…

Fluid Dynamics · Physics 2015-05-27 Jared P. Whitehead , Charles R. Doering

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 investigate by direct numerical simulation Rayleigh-B\'enard convection in a rotating rectangular cell with rotation vector and gravity perpendicular to each other. The flow is two dimensional near the onset of convection with convection…

Fluid Dynamics · Physics 2022-05-12 K. Lüdemann , A. Tilgner

Direct numerical simulations are carried out to study flow structure and transport properties in turbulent Rayleigh-B\'{e}nard convection in a cylindrical cell of aspect ratio one with an imposed axial magnetic field. Flows at the Prandtl…

Fluid Dynamics · Physics 2020-06-24 Ruslan Akhmedagaev , Oleg Zikanov , Dmitry Krasnov , Joerg Schumacher

We present the results of direct numerical simulations of Rayleigh-B\'enard convection in the presence of a uniform vertical magnetic field near instability onset. We have done simulations in boxes with square as well as rectangular…

Fluid Dynamics · Physics 2014-09-10 Arnab Basak , Rohit Raveendran , Krishna Kumar

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

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…

Fluid Dynamics · Physics 2019-06-18 Marten Klein , Heiko Schmidt

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

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

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 $Pr\approx0.0093$…