Rotating rayleighbenard convection technische universiteit. Dynamics of plumes in turbulent rayleighbenard convection. The main objective of this article is part of a research program to link the dynamics of fluid flows with the structure of these fluid flows in physical space and the transitions of this structure. We identify the coherent structures plumes present in numerical solutions of turbulent rayleighbenard convection, a canonical example. Hot red fluid rises from the hot bottom plate while cold blue fluid falls down. It becomes fully turbulent in the areas where the largescale circulation impinge or leave the bottom plate. An overview of emergent order in farfromequilibrium. Rayleighbenard convection was investigated using experiments and numerical simulations for rayleigh numbers in the range of 1. We use a conditional sampling compositing technique to extract the typical. The computed critical rayleigh number for these finiteaspectratio cavities is well above the value 1708, which is appropriate for infinite. Heat transfer and large scale dynamics in turbulent. Some general properties of the critical rayleigh number, rc, with respect to change of boundary conditions or system size are derived.
Linear and nonlinear pattern selection in rayleighbenard. Earlier studies suggested that velocity superstructures were smaller than their thermal. This allows for an absolute comparison of pdfs because the. The book describes the basic methods of investigating convection patterns, and the types of two and threedimensional flows, pattern defects, and sequences of convection regime changes. Here we complement previous studies by concentrating on higherre turbulent rotating rayleigh benard convection, providing a detailed examination of the influence of vertical boundary conditions on the dynamics of the statistically steady turbulent. The following matlab project contains the source code and matlab examples used for rayleigh benard convection. Boundary layer structure in turbulent rayleighbenard convection. Structures and dynamics advanced series in nonlinear dynamics by alexander v getling author 5. Heat transport in rayleighbenard convection and angular. Free convection and the rayleigh number arunn narasimhan. There are four distinct flow structures in this regime, namely. Rayleighbenard convection is a type of natural convection, occurring in a plane horizontal layer of fluid heated from below, in which the fluid develops a regular pattern of convection cells known as benard cells. Appearance of 3d structures on quasi2d convection rolls.
Radial boundary layer structure and nusselt number in rayleighbenard convection. Experimental techniques for turbulent taylorcouette flow and. Dec 19, 2018 lagrangian characterization of rotating rayleighbenard convection citation for published version apa. Here we investigate the morphological properties of plumes in rotating rb convection using threedimensional direct numerical simulations dns and. The source code and files included in this project are listed in the project files section, please make sure whether the listed source code meet your. This model of thermal convection is a paradigm for nonlinear and chaotic dynamics, pattern formation and fully developed turbulence kadano. Large scale spatial structures and temporal chaos in. Structures and dynamics in russian, editorial urss, moscow 1999. Rayleigh benard convection is studied and the effect of change of aspect ratio and change of initial condition is investigated through numerical simulation by the use of a commercial computational fluid. Applications of these pdf formulae to study the fluctuations in turbulent rayleighbenard convection are then discussed. Structures and dynamics advanced series in nonlinear dynamics on. Heat transfer and large scale dynamics in turbulent rayleigh. Our analysis of both boundary layers shows that the nearwall dynamics combines elements of forced blasiustype and natural convection. Rotating rayleighbenard convection rrbc is studied as a paradigmatic example of pattern formation and spatiotemporal chaos.
Apr 23, 2012 boundary layer structure in turbulent rayleighbenard convection article pdf available in journal of fluid mechanics 706 april 2012 with 281 reads how we measure reads. The author pays special attention to the question of how various factors mainly reducible to initial and boundary conditions determine the shapes and sizes of. The system is a fluid heated from below and cooled from above with periodic sidewalls and impermeable horizontal plates. Cessation and reversals of largescale structures in square rayleigh. Boundary layer structure in turbulent rayleighbenard convection article pdf available in journal of fluid mechanics 706 april 2012 with 281 reads how we measure reads.
In this thesis classical rayleighbenard convection rbc is subjected to. Investigation on instability of rayleighbenard convection. Rotating turbulent rayleighbenard convection subject to. Stevens, 1alexander blass, xiaojue zhu, roberto verzicco,1,2 and detlef lohse1,3 1physics of fluids group, max planck center twente for complex fluid dynamics, j. If this is the first time you use this feature, you will be asked to authorise cambridge core to connect with your account. Measurement lines arranged parallel to the magnetic field effectively represent 3d structures on the convection rolls.
Various sequences captured at selected positions of the heating plate show that the boundary layer is a very transient flow region characterized by coherent structures that permanently evolve. The navierstokes equations are solved by the pressure projection method on a staggered grid. Kunnenb a multiscale modeling and simulation, faculty eemcs, university of twente, enschede, the netherlands. Our aim is to explore the geometrical characterization of. Rayleighb enard convection, thirty years of experimental, theoretical, and modeling work paul manneville laboratoire dhydrodynamique, ecole polytechnique f91128 palaiseau cedex, france email. We identify the coherent structures plumes present in numerical solutions of turbulent rayleighbenard convection, a canonical example of a turbulent plume ensemble. Introduction turbulent rayleighbenard convection can be initiated in a. We perform a numerical study of the heat transfer and flow structure of rayleighbenard rb convection in in most cases regular porous media, which are comprised of circular, solid obstacles located on a square lattice.
The hyperbolic flux terms are discretized explicitly cd, maccormack and richtmyer while the diffusive terms are dealt with both explicitly and implicitly. This draft was prepared using the latex style file belonging to the journal of fluid. Rayleighbenard convection rbc is the buoyancydriven. Jun 18, 2014 numerical simulation of highly turbulent twodimensional rayleigh benard convection. Effects of boundaries on rayleighbenard convection. Rayleighbenard and benardmarangoni convection if you take a horizontal fluid layer and maintain a temperature difference across it by heating from below and cooling from above, you will find that the fluid flows in a pattern of convection cells if the temperature difference exceeds a threshold value. Structures and dynamics, 1998, world scientific publishers. Convection is often studied in the classical rayleighbenard rb. Experiments with rayleighbenard convection springerlink. Bottom wall represents higher temperature, and top wall represents colder temperature. Here we complement previous studies by concentrating on higherre turbulent rotating rayleighbenard convection.
Sep 10, 2012 natural convection due to thermal gradients are simulated in a 2d rectangular domain. Ecke, pattern dynamics and heat transport in rotating rayleighbenard convection, chaos 2, 163 1992. Appearance of 3d structures on quasi2d convection rolls in a. Rayleigh benard convection is studied and the effect of change of aspect ratio and change of initial condition is investigated through numerical simulation by the use of a commercial computational fluid dynamics package fluent. Lagrangian characterization of rotating rayleighbenard.
The phenomenology of the different types of scaling behavior. The effects of boundary conditions on the linear stability of finite cell pure fluid rayleighbenard convection are investigated via a variational formalism and a perturbative approach. Plume dynamics in rotating rayleighbenard convection. Experimental techniques for turbulent taylorcouette flow. For interested readers, more on these experiments can be read from the book by a. This snapshot was taken from a movie based on data from a rayleighbenard convection simulation. In this study, the effects of prandtl number on the primary and secondary instability of the rayleighbenard convection problem has been investigated using the lattice boltzmann method. We study turbulent rayleighbenard convection in air at rayleigh number. Sketch of the splitting of the kinetic a and thermal b dissipation rates on which the gl theory is based. The source code and files included in this project are listed in the project files. Rayleighb enard convection, thirty years of experimental. Hot red fluid rises from the hot bottom plate while cold blue fluid falls. Numerical simulation of highly turbulent twodimensional rayleighbenard convection. Effect of initial condition and influence of aspect ratio.
General temporal evolution and pdf of modal amplitudes. Pattern formation in turbulent rb convection is a complex topic and a full characterization of the coherent fluid structures thermalsplumes, ctcs involved in this dynamics is still missing. Rayleigh benard convection file exchange matlab central. Turbulent thermal superstructures in rayleighbanard convection.
Publishers pdf, also known as version of record includes final page. Rayleighbenard convection with a melting boundary irphe. The main objective of this article is part of a research program to link the dynamics of fluid flows with the structure and its transitions in the physical spaces. A sketch of rayleighbenard convection in a cylindrical cell with unit aspect.
Dynamics of reorientations and reversals of largescale. The angle of directional change of tracer trajectories in rotating rayleighbenard convection is studied as a function of the time increment. Statistics and scaling in turbulent rayleighbenard convection. Perkins in partial ful llment of the requirements for the degree doctor of philosophy in the school of physics georgia institute of technology december 2011. Pdf the main objective of this article is part of a research program to link the dynamics of fluid flows with the structure and its transitions in the. A 2d model of rayleigh benard convection was created. Rayleighbenard convection in a nearcritical fluid in the. A unifying view on turbulent transport enhancement through coherent structure manipulation kai leong chong,1. Mechanisms of instability in rayleighbenard convection a thesis presented to the academic faculty by adam c.
Fluids 26, 054104 2014 where h is the domain height. Mechanisms of instability in rayleigh benard convection a thesis presented to the academic faculty by adam c. Download rayleigh benard convection simulator for free. The dimensionless taylor number is defined as an external file that holds a. Kunnenb a multiscale modeling and simulation, faculty eemcs, university of twente, enschede, the netherlands b faculty of applied physics, fluid dynamics laboratory, eindhoven university of technology, eindhoven, the netherlands published online. We present three topics in fluid dynamics which have recently sparkled the interest of the physics community. Rayleighbenard convection, bifurcated attractor, basin of attraction, structural stability, roll structure. Boundary layer structure in a rough rayleighbenard cell filled with air volume 786 o. Turbulent thermal superstructures in rayleighbenard convection richard j.
We investigate the development of 3d structures on quasi2d convection rolls of rayleighbenard convection in a liquid metal layer with an imposed horizontal magnetic field using uvp. Rayleighbenard convection is a type of natural convection, occurring in a plane horizontal. Pdf rayleighbenard natural convection heat transfer. Benardrayleigh convection is one of the most commonly studied convection phenomena because of its analytical and experimental accessibility. Turbulent convection is ubiquitous in nature and in many engineering applications. Homogeneous rayleighbenard convection scaling, heat transport and structures e. The dynamics of the large scale wind, its azimuthal oscillation, diffusion, reorientation, cessation, and possible 504 ahlers, grossmann, and lohse.
Lagrangian characterization of rotating rayleighbenard convection. Natural convection due to thermal gradients are simulated in a 2d rectangular domain. Rayleigh benard convection in matlab download free open. Dynamics of plumes in turbulent rayleighbenard convection article pdf available in european journal of mechanics bfluids 72 may 2018 with 280 reads how we measure reads. As a prototype of problem and to demonstrate the main ideas, we study the twodimensional rayleigh benard convection. The first instability mode is a single roll creating a vortextype motion for cavities with aspect ratio less than two. Download rayleighbenard convection simulator for free.
Selecting this option will search all publications across the scitation platform selecting this option will search all publications for the publishersociety in context. Steadystate rayleighbenard convection in a medium with parameters close to the. Boussinesq approximation calculation and subtraction of the basic state nondimensionalisation boundary conditions linear stability analysis lorenz model inclusion of nonlinear interactions seek bifurcations. The redshaded areas of the cell show regions with hot. Rapidly rotating turbulent rayleighbenard convection. Recent developments in rayleighbenard convection and. Boundary layer structure in turbulent rayleighbenard. Boundary layers in turbulent rayleighbenard convection in air. To demonstrate the main ideas, we study the twodimensional rayleighbenard convection, which serves as a prototype problem. A common feature of these systems is that the entities that selforganize are coupled to one another in some way, either through local interactions or through a continuous media. Large scale spatial structures and temporal chaos in rayleigh. Perkins in partial ful llment of the requirements for the degree doctor.
Directional change of tracer trajectories in rotating. Introduction fluid motion driven by thermal gradients. Coherence of temperature and velocity superstructures in turbulent. If you have a disability and are having trouble accessing information on this website or need materials in an alternate format, contact web. Cross, chaotic domainstructure in rotating convection, phys. This model of thermal convection is a paradigm for nonlinear and chaotic dynamics. The visible quantity is the temperature of the fluid, where red and blue indicate hot and cold fluid, respectively.