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Related papers: Bounds for Turbulent Transport

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An important question in turbulent Rayleigh-B\'{e}nard convection (RBC) is the effectiveness of convective heat transport, which is conveniently described via the scaling of the Nusselt number (${\rm{Nu}}$) with the Rayleigh (${\rm{Ra}}$)…

Fluid Dynamics · Physics 2020-04-29 P. Urban , T. Králík , P. Hanzelka , V. Musilová , T. Věžník , D. Schmoranzer , L. Skrbek

We prove the first rigorous bound on the heat transfer for three-dimensional Rayleigh-B\'enard convection of finite-Prandtl-number fluids between free-slip boundaries with an imposed heat flux. Using the auxiliary functional method with a…

Fluid Dynamics · Physics 2018-04-11 Giovanni Fantuzzi

We establish a theoretical framework for predicting friction and heat transfer coefficients in variable-properties forced air convection. Drawing from concepts in high-speed wall turbulence, which also involves significant temperature,…

Fluid Dynamics · Physics 2024-12-18 Davide Modesti , Sergio Pirozzoli

We consider front propagation in a reactive Boussinesq system in an infinite vertical strip. We establish nonlinear stability of planar fronts for narrow domains when the Rayleigh number is not too large. Planar fronts are shown to be…

Chaotic Dynamics · Physics 2007-05-23 Peter Constantin , Alexander Kiselev , Lenya Ryzhik

In this study we report numerical results of turbulent transport of heat $Nu$ and angular momentum $\nu_{t}/\nu$ in Taylor-Couette (TC) flows subjected to a radial temperature gradient. Direct numerical simulations are performed in a TC…

Fluid Dynamics · Physics 2021-11-25 X. -Y. Leng , J. -Q. Zhong

Boiling is an extremely effective way to promote heat transfer from a hot surface to a liquid due to several mechanisms many of which are not understood in quantitative detail. An important component of the overall process is that the…

Lagrangian studies of the local temperature mixing and heat transport in turbulent Rayleigh-Benard convection are presented, based on three-dimensional direct numerical simulations. Contrary to vertical pair distances, the temporal growth…

Fluid Dynamics · Physics 2008-04-09 Joerg Schumacher

We study thermal fluctuation corrections to charge and heat conductivity in systems with locally conserved energy and charge, but without locally conserved momentum. Thermal fluctuations may naturally lead to a lower bound on diffusion…

Statistical Mechanics · Physics 2015-07-22 Pavel Kovtun

We present numerical simulations, using two complementary setups, of rotating Boussinesq thermal convection in a three-dimensional Cartesian geometry with misaligned gravity and rotation vectors. This model represents a small region at a…

Solar and Stellar Astrophysics · Physics 2020-02-19 Laura K. Currie , Adrian J. Barker , Yoram Lithwick , Matthew K. Browning

The dynamics of Rayleigh-Taylor turbulence convection in presence of an alternating, time periodic acceleration is studied by means of extensive direct numerical simulations of the Boussinesq equations. Within this framework, we discover a…

Fluid Dynamics · Physics 2019-03-27 G. Boffetta , M. Magnani , S. Musacchio

Laboratory experiments were conducted to study heat transport characteristics in a nonhomogeneously heated fluid annulus subjected to rotation along the vertical axis (z). The nonhomogeneous heating was obtained by imposing radial and…

We prove new bounds on the heat flux out of the bottom boundary, $\mathcal{F}_B$, for a fluid at infinite Prandtl number, heated internally between isothermal parallel plates under two kinematic boundary conditions. In uniform internally…

Fluid Dynamics · Physics 2024-03-22 Ali Arslan , Ruben E. Rojas

In this paper, the boundary flex control problem of non stationary equation governing the coupled mass and heat flow of a viscous incompressible fluid in a generalized Boussinesq approximation by assuming that viscosity and heat…

Optimization and Control · Mathematics 2012-07-18 Gol Kim , Gennady Valentinovich Alekseev

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

We consider the reactive Boussinesq equations in a slanted cylinder, with zero stress boundary conditions and arbitrary Rayleigh number. We show that the equations have non-planar traveling front solutions that propagate at a constant…

Analysis of PDEs · Mathematics 2007-05-23 H. Berestycki , P. Constantin , L. Ryzhik

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 turbulent Rayleigh-B\'enard convection within two immiscible fluid layers, aiming to understand how the layer thickness and fluid properties affect the heat transfer (characterized by the Nusselt number $Nu$) in…

Fluid Dynamics · Physics 2022-05-24 Hao-Ran Liu , Kai Leong Chong , Rui Yang , Roberto Verzicco , Detlef Lohse

Turbulent thermal convection is characterized by the formation of large-scale structures and strong spatial inhomogeneity. This work addresses the relative heat transport contributions of the large-scale plume ejecting versus plume…

Fluid Dynamics · Physics 2021-04-09 Philipp Reiter , Olga Shishkina , Detlef Lohse , Dominik Krug

Thermal convection of fluid is a more efficient way than diffusion to carry heat from hot sources to cold places. Here, we experimentally study the Rayleigh-B\'enard convection of aqueous glycerol solution in a cubic cell with suspensions…

Fluid Dynamics · Physics 2021-09-14 Shi-Yuan Hu , Kai-Zhe Wang , Lai-Bing Jia , Jin-Qiang Zhong , Jun Zhang

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
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