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This study seeks to characterise the breakdown of the steady 2D solution in the flow around a 180-degree sharp bend to infinitesimal 3D disturbances using a linear stability analysis. The stability analysis predicts that 3D transition is…

Fluid Dynamics · Physics 2017-08-30 Azan M. Sapardi , Wisam K. Hussam Alban Pothérat , Gregory J. Sheard

We study two-dimensional Rayleigh-B\'{e}nard convection with Navier-slip, fixed temperature boundary conditions and establish bounds on the Nusselt number. As the slip-length varies with Rayleigh number $\rm{Ra}$, this estimate interpolates…

Analysis of PDEs · Mathematics 2021-09-28 Theodore D. Drivas , Huy Q. Nguyen , Camilla Nobili

We present high-precision experimental and numerical studies of the Nusselt number $Nu$ as functions of the Rayleigh number $Ra$ in geostrophic rotating convection with domain aspect ratio ${\Gamma}$ varying from 0.4 to 3.8 and the Ekman…

Fluid Dynamics · Physics 2021-08-04 Hao-Yuan Lu , Guang-Yu Ding , Jun-Qiang Shi , Ke-Qing Xia , Jin-Qiang Zhong

The divergence-free time-independent velocity vector field has been determined so as to maximise heat transfer between two parallel plates of a constant temperature difference under the constraint of fixed total enstrophy. The present…

Fluid Dynamics · Physics 2018-08-03 Shingo Motoki , Genta Kawahara , Masaki Shimizu

Rayleigh-B\'enard convection (RBC) and Taylor-Couette Flow (TCF) are two paradigmatic fluid dynamical systems frequently discussed together because of their many similarities despite their different geometries and forcing. Often these…

Fluid Dynamics · Physics 2020-10-28 Bruno Eckhardt , Charles R. Doering , Jared P. Whitehead

We report results for the temperature profiles of turbulent Rayleigh-B\'enard convection (RBC) in the interior of a cylindrical sample of aspect ratio $\Gamma \equiv D/L = 0.50$ ($D$ and $L$ are the diameter and height respectively).…

A numerical investigation of an asymptotically reduced model for quasi-geostrophic Rayleigh-B\'enard convection is conducted in which the depth-averaged flows are numerically suppressed by modifying the governing equations. The Reynolds…

Fluid Dynamics · Physics 2023-08-23 Tobias G. Oliver , Adrienne S. Jacobi , Keith Julien , Michael A. Calkins

Combined measurements of velocity components and temperature in a turbulent Rayleigh-B\'enard convection flow at a low Prandtl number of $\mathit{Pr}= 0.029$ and Rayleigh numbers between $10^6 \le \mathit{Ra} \le 6 \times 10^7$ are…

Fluid Dynamics · Physics 2020-02-19 Till Zürner , Felix Schindler , Tobias Vogt , Sven Eckert , Jörg Schumacher

Spatial regions that do not mix effectively with their surroundings and thus contribute less to the heat transport in fully turbulent three-dimensional Rayleigh-B\'{e}nard flows are identified by Lagrangian trajectories that stay together…

We study the dynamics of thermal and momentum boundary regions in three-dimensional direct numerical simulations of Rayleigh-B\'enard convection for the Rayleigh number range $10^5 \le Ra \le 10^{11}$ and $Pr=0.7$. Using a Cartesian slab…

We present mesoscale numerical simulations of Rayleigh-B\'{e}nard convection in a two-dimensional concentrated emulsion, confined between two parallel walls, heated from below and cooled from above, under the effect of buoyancy forces. The…

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

An interesting question in turbulent convection is how the heat transport depends on the strength of thermal forcing in the limit of very large thermal forcing. Kraichnan predicted [Phys. Fluids {\bf 5}, 1374 (1962)] that the heat transport…

Chaotic Dynamics · Physics 2009-11-13 Emily S. C. Ching , T. C. Ko

We report a high-resolution numerical study of two-dimensional (2D) miscible Rayleigh-Taylor (RT) incompressible turbulence with the Boussinesq approximation. An ensemble of 100 independent realizations were performed at small Atwood number…

Fluid Dynamics · Physics 2015-06-16 Quan Zhou

We study turbulent Rayleigh-B\'enard convection over four decades of Rayleigh numbers 4E8 < Ra < 2E12, while harmonically modulating the temperatures of the plates of our cylindrical cell. We probe the flow by temperature sensors placed in…

Fluid Dynamics · Physics 2022-04-13 P. Urban , P. Hanzelka , T. Králík , V. Musilová , L. Skrbek

We consider Rayleigh-B\'enard convection in a layer of fluid between rough no-slip boundaries where the top and bottom boundary heights are functions of the horizontal coordinates with square-integrable gradients. We use the background…

Fluid Dynamics · Physics 2016-10-20 David Goluskin , Charles R. Doering

The horizontal convection within a rectangle tank is numerically simulated. The flow is found to be unsteady at high Rayleigh numbers. There is a Hopf bifurcation of $Ra$ from steady solutions to periodic solutions, and the critical…

Fluid Dynamics · Physics 2009-05-20 Liang Sun , Dong-Jun MA , Wei Zhang , De-Jun Sun

A series of direct numerical simulations of Rayleigh-B\'enard convection, the flow in a fluid layer heated from below and cooled from above, were conducted to investigate the effect of mixed insulating and conducting boundary conditions on…

By tailoring the geometry of the upper boundary in turbulent Rayleigh-B\'enard convection we manipulate the boundary layer -- interior flow interaction, and examine the heat transport using the Lattice Boltzmann method. For fixed amplitude…

Fluid Dynamics · Physics 2015-09-14 Srikanth Toppaladoddi , Sauro Succi , John S. Wettlaufer

We present high-resolution direct numerical simulation studies of turbulent Rayleigh-Benard convection in a closed cylindrical cell with an aspect ratio of one. The focus of our analysis is on the finest scales of convective turbulence, in…

Fluid Dynamics · Physics 2013-12-04 Janet D. Scheel , Mohammad S. Emran , Joerg Schumacher
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