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Related papers: Bounds for convection between rough boundaries

200 papers

Unlike solids, the heat transfer in fluids can be greatly enhanced due to the presence of convection. Under gravity, an unevenly distributed temperature field results in differences in buoyancy, driving fluid motion that is seen in…

Fluid Dynamics · Physics 2024-10-04 Jinzi Mac Huang , Jun Zhang

We present experimental heat transport measurements of turbulent Rayleigh-B\'{e}nard convection with rotation about a vertical axis. The fluid, water with Prandtl number ($\sigma$) about 6, was confined in a cell which had a square cross…

Fluid Dynamics · Physics 2015-05-13 Yuanming Liu , Robert E. Ecke

We report the existence of two new limiting turbulent regimes in horizontal convection (HC) using direct numerical simulations at intermediate to low Prandtl numbers. The flow driven by a horizontal gradient along a horizontal surface,…

Fluid Dynamics · Physics 2020-05-01 Pierre-Yves Passaggia , Alberto Scotti , Brian L. White

The heat transfer mechanism in Rayleigh-Benard convection in a liquid with a mean temperature close to its boiling point is studied through numerical simulations with point-like vapor bubbles, which are allowed to grow or shrink through…

Fluid Dynamics · Physics 2015-05-13 Paolo Oresta , Roberto Verzicco , Detlef Lohse , Andrea Prosperetti

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

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

The vertical heat transfer in B\'enard-Marangoni convection of a fluid layer with infinite Prandtl number is studied by means of upper bounds on the Nusselt number $Nu$ as a function of the Marangoni number $Ma$. Using the background method…

Fluid Dynamics · Physics 2018-04-11 Giovanni Fantuzzi , Anton Pershin , Andrew Wynn

We report on experimental determinations of the temperature field in the interior (bulk) of turbulent Rayleigh-Benard convection for a cylindrical sample with aspect ratio (diameter over height) of 0.50, both in the classical and in the…

Fluid Dynamics · Physics 2015-06-19 Guenter Ahlers , Eberhard Bodenschatz , Xiaozhou He

We present a systematic investigation of the effects of roughness geometry on turbulent Rayleigh-B\'enard convection (RBC) over rough plates with pyramid-shaped and periodically distributed roughness elements. Using a parameter $\lambda$…

Fluid Dynamics · Physics 2017-07-26 Yi-Chao Xie , Ke-Qing Xia

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

We perform direct numerical simulations of wall sheared Rayleigh-B\'enard (RB) convection for Rayleigh numbers up to $Ra=10^8$, Prandtl number unity, and wall shear Reynolds numbers up to $Re_w=10000$. Using the Monin-Obukhov length…

Temperature and velocity oscillations have been found in a rectangular Rayleigh-B\'{e}nard convection cell, in which one large scale convection roll exists. At $Ra=8.9 \times 10^{11}$ and $Pr=4$, temperature oscillation can be observed in…

Fluid Dynamics · Physics 2009-11-13 Sheng-Qi Zhou , Chao Sun , Ke-Qing Xia

In turbulent Rayleigh-B\'enard convection one seeks the relationship between the heat transport, captured by the Nusselt number, and the temperature drop across the convecting layer, captured by Rayleigh number. In experiments, one measures…

Chaotic Dynamics · Physics 2018-05-23 Scott Weady , Sahil Agarwal , Larry Wilen , John Wettlaufer

Rayleigh-Benard convection and Taylor-Couette flow are two canonical flows that have many properties in common. We here compare the two flows in detail for parameter values where the Nusselt numbers, i.e. the thermal transport and the…

Fluid Dynamics · Physics 2017-04-12 Hannes Brauckmann , Bruno Eckhardt , Joerg Schumacher

We consider the flow of an upper convected Maxwell fluid in the limit of high Weissenberg and Reynolds number. In this limit, the no-slip condition cannot be imposed on the solutions. We derive equations for the resulting boundary layer and…

Analysis of PDEs · Mathematics 2015-06-04 Michael Renardy , Xiaojun Wang

The basic stationary buoyant flow in a vertical annular porous passage induced by a boundary temperature difference is investigated. The vertical cylindrical boundaries are considered both isothermal and permeable to external fluid…

Fluid Dynamics · Physics 2023-02-03 A. Barletta , M. Celli , D. A. S. Rees

We investigate the influence of the temperature boundary conditions at the sidewall on the heat transport in Rayleigh-B\'enard (RB) convection using direct numerical simulations. For relatively low Rayleigh numbers Ra the heat transport is…

Fluid Dynamics · Physics 2014-12-24 Richard J. A. M. Stevens , Detlef Lohse , Roberto Verzicco

A pure and incompressible material is confined between two plates such that it is heated from below and cooled from above. When its melting temperature is comprised between these two imposed temperatures, an interface separating liquid and…

Fluid Dynamics · Physics 2020-02-11 Jhaswantsing Purseed , Benjamin Favier , Laurent Duchemin , Eric W. Hester

In this numerical study on Rayleigh-B\'enard convection we seek to improve the heat transfer by passive means. To this end we introduce a single tilted conductive barrier centered in an aspect ratio one cell, breaking the symmetry of the…

Fluid Dynamics · Physics 2021-01-04 Shuang Liu , Sander G. Huisman

Atmospheric convection is an essential aspect of atmospheric movement, and it is a source of errors in Climate Models. Being able to generate approximate limit formulas and compare the estimations they produce, could give a way to reduce…

Analysis of PDEs · Mathematics 2018-11-09 C. V. Valencia-Negrete , C. Gay-García , A. A. Carsteanu