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Related papers: Algebraic Bounds on the Rayleigh-B\'enard attracto…

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The previous investigation on Rayleigh-B\'enard convection of a dilute classical gas [T. Kita: J. Phys. Soc. Jpn. {\bf 75} (2006) 124005] is extended to calculate entropy change of the convective transition with the rigid boundaries. We…

Statistical Mechanics · Physics 2009-11-13 Takafumi Kita

We investigate the influence of the thermal properties of the boundaries in turbulent Rayleigh-B\'enard convection on analytical upper bounds on convective heat transport. We model imperfectly conducting bounding plates in two ways: using…

Fluid Dynamics · Physics 2010-08-17 Ralf W. Wittenberg

It is shown that homogeneous Rayleigh-Benard flow, i.e., Rayleigh-Benard turbulence with periodic boundary conditions in all directions and a volume forcing of the temperature field by a mean gradient, has a family of exact, exponentially…

Chaotic Dynamics · Physics 2007-05-23 E. Calzavarini , C. R. Doering , J. D. Gibbon , D. Lohse , A. Tanabe , F. Toschi

A series of numerical simulations of Rayleigh-B{\'e}nard convection in a cubic cavity are conducted in order to examine the structure of the thermal boundary layer in case of mixed boundary conditions. The main goal of the study is the…

Fluid Dynamics · Physics 2020-10-29 Andrei Sukhanovskii , Andrei Vasiliev

We numerically investigate the structures of the near-plate temperature profiles close to the bottom and top plates of turbulent Rayleigh-B\'{e}nard flow in a cylindrical sample at Rayleigh numbers Ra=10^8 to Ra=2\times10^{12} and Prandtl…

We investigate the influence of the thermal properties of the boundaries in turbulent Rayleigh-Benard convection on analytical bounds on convective heat transport. Using the Doering-Constantin background flow method, we systematically…

Fluid Dynamics · Physics 2008-11-20 Ralf W. Wittenberg

Solid state convection can take place in the rocky or icy mantles of planetary objects and these mantles can be surrounded above or below or both by molten layers of similar composition. A flow toward the interface can proceed through it by…

Fluid Dynamics · Physics 2018-05-23 Stéphane Labrosse , Adrien Morison , Renaud Deguen , Thierry Alboussière

Rayleigh-B\'enard convection in the turbulent regime is studied using statistical methods. Exact evolution equations for the probability density function of temperature and velocity are derived from first principles within the framework of…

Fluid Dynamics · Physics 2011-03-04 J. Lülff , M. Wilczek , R. Friedrich

Rayleigh--B\'enard (RB) convection, the flow in a fluid layer heated from below and cooled from above, is used to analyze the transition to the geostrophic regime of thermal convection. In the geostrophic regime, which is of direct…

We consider Rayleigh-B\'enard convection as modeled by the Boussinesq equations, in case of infinite Prandtl number. There is a broad interest in bounds of the upwards heat flux, as given by the Nusselt number ${\rm Nu}$, in terms of the…

Analysis of PDEs · Mathematics 2017-10-11 Camilla Nobili , Felix Otto

A recently developed so-called explicit algebraic Reynolds-stress (EARS) model is applied to a transitioning atmospheric boundary layer (ABL). The simulation describes a diurnal cycle with a deep convective ABL during daytime and an…

Fluid Dynamics · Physics 2021-08-16 Velibor Želi , Stefan Wallin , Arne V. Johansson , Geert Brethouwer

We discuss artificial boundary conditions for stationary Navier-Stokes flows past bodies in the half-plane, for a range of low Reynolds numbers. When truncating the half-plane to a finite domain for numerical purposes, artificial boundaries…

Fluid Dynamics · Physics 2012-08-20 Christoph Boeckle , Peter Wittwer

In this dissertation two-dimensional buoyancy-driven flows are investigated. While usually the Navier-Stokes equations are equipped with no-slip boundary conditions here we focus on the Navier-slip conditions that, depending on the system…

Analysis of PDEs · Mathematics 2024-09-25 Fabian Bleitner

We describe a framework for bounding extreme values of quantities on global attractors of differential dynamical systems. A global attractor is the minimal set that attracts all bounded sets; it contains all forward-time limit points. Our…

Dynamical Systems · Mathematics 2020-09-18 David Goluskin

In most results concerning bounds on the heat transport in the Rayleigh-B\'{e}nard convection problem no-slip boundary conditions for the velocity field are assumed. Nevertheless it is debatable, whether these boundary conditions reflect…

Fluid Dynamics · Physics 2022-01-13 Camilla Nobili

The structure of the boundary layers in turbulent Rayleigh-Benard convection is studied by means of three-dimensional direct numerical simulations. We consider convection in a cylindrical cell at an aspect ratio one for Rayleigh numbers of…

Fluid Dynamics · Physics 2012-09-04 Nan Shi , Mohammad S. Emran , Joerg Schumacher

Boundary layers play an important role in controlling convective heat transfer. Their nature varies considerably between different application areas characterized by different boundary conditions, which hampers a uniform treatment. Here, we…

Fluid Dynamics · Physics 2013-03-20 K. Petschel , S. Stellmach , M. Wilczek , J. Lülff , U. Hansen

A semi-explicit formula of solution to the boundary layer system for thermal layer derived from the compressible Navier-Stokes equations with the non-slip boundary condition when the viscosity coefficients vanish is given, in particular in…

Analysis of PDEs · Mathematics 2016-08-10 Cheng-Jie Liu , Ya-Guang Wang , Tong Yang

Inverse problems in computational mechanics consist of inferring physical fields that are latent in the model describing some observable fields. For instance, an inverse problem of interest is inferring the Reynolds stress field in the…

Computational Physics · Physics 2020-06-24 Carlos A. Michelén Ströfer , Xinlei Zhang , Heng Xiao , Olivier Coutier-Delgosha

The problem of pattern selection in absolutely unstable open flow systems is investigated by considering the example of Rayleigh-B\'{e}nard convection. The spatiotemporal structure of convection rolls propagating downstream in an externally…

patt-sol · Physics 2015-06-26 D. Roth , P. Buechel , M. Luecke , H. W. Mueller , M. Kamps , R. Schmitz