Rayleigh-benard convection structures and dynamics pdf

With additional system rotation along an axis parallel to gravity, individual. This barcode number lets you verify that youre getting exactly the right version or edition of a book. Natural convection due to thermal gradients are simulated in a 2d rectangular domain. Rayleighbenard convection of a viscoplastic liquid in a. Our analysis of both boundary layers shows that the nearwall dynamics combines elements of forced blasiustype and natural convection. Heat transfer and large scale dynamics in turbulent rayleigh. Turbulent superstructures in rayleighbenard convection. We conduct direct numerical simulations for turbulent rayleighbenard rb convection, driven simultaneously by two scalar components say, temperature and salt concentration with different molecular diffusivities, and measure the respective fluxes and the reynolds number. The plumes are coherent structures that have a mushroomlike form, when viewed from the side and a sheetlike form when viewed from above.

Numerical simulations are carried out in a twodimensional 2d rectangular cell with aspect ratio 2 using air as the working fluid across four decades of rayleigh number. The dynamical system shows pitchfork, hopf and gluing bifurcations near the onset of rbc of low prandtlnumber. This snapshot was taken from a movie based on data from a rayleighbenard convection simulation. Introduction turbulent rayleighbenard convection can be initiated in a. Benardrayleigh convection is one of the most commonly studied convection phenomena because of its analytical and experimental accessibility. In this paper, we propose an efficient way to quantify plume merging using three accessible statistics. A series of visualization studies, fourier analysis and proper orthogonal decomposition are employed to qualitatively and quantitatively inspect the largescale structures length and time scales, spatial organization, and dynamic properties. Rayleighbenard convection is characterized by three control parameters, namely. Statistics of coherent structures in twodimensional. This option allows users to search by publication, volume and page selecting this option will search the current publication in context.

Dynamics and structure in the physical space article pdf available in communications in mathematical sciences 53 november 2006 with 181 reads how we. Structures and dynamics advanced series in nonlinear dynamics by alexander v getling author 5. Rayleighbenard convection structures and dynamics advanced in nonlinear dynamics by alexander v getling. Coherence of temperature and velocity superstructures in turbulent rayleighbenard flow volume 887 dominik krug, detlef lohse, richard j. It will now serve us to introduce the nonlinear dynamics of dissipative structures, at a phenomenological level. This project is intended to visualize the thermal plumes in a cylindrical turbulent rayleighbenard convection cell by plif planar laser induced fluorescence in absence of rotation or in rotation. Physics of fluids 26, 015112 2014 thermal boundary layer near roughnesses in turbulent rayleighbenard convection. Here we investigate the morphological properties of plumes in rotating rb convection using threedimensional direct numerical simulations dns and. This invaluable book presents a concise but systematic account of the formation of spatial flow structures in a horizontal fluid layer heated from below. Structure of thermal boundary layers in turbulent rayleigh. May 29, 2018 turbulent rayleighbenard convection displays a largescale order in the form of rolls and cells on lengths larger than the layer height once the fluctuations of temperature and velocity are removed. 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. Here we investigate the morphological properties of plumes in rotating rbconvection using threedimensional direct numerical simulations dns and. Aug 03, 2016 rayleigh benard thermal convection 3d simulation with lbm.

Stephan weiss is the group leader of the convection group at the laboratory for fluids, pattern formation and biocomplexity. Note that t w is the di erence in temperature between the wall and the ambient or core. Busse 1972 pointed out that it would be surprising if the dynamics of convection lacked the. The rayleigh benard convection is a threedimensional flow in a rectangular box, bounded by rigid impermeable walls and heated from below. Radial boundary layer structure and nusselt number in rayleighbenard convection. Introduction rayleighbenard rb convectionthe buoyancy driven.

Selecting this option will search all publications across the scitation platform selecting this option will search all publications for the publishersociety in context. Model statement the geometry of the rectangular cavity and the coordinate system are shown in. Rayleighbenard convection rbc is the buoyancydriven. Rayleighb enard convection, thirty years of experimental, theoretical, and modeling work paul manneville laboratoire dhydrodynamique, ecole polytechnique f91128 palaiseau cedex, france email. Benard convection an overview sciencedirect topics. Pdf plume dynamics in rotating rayleighbenard convection. Turbulent rayleighbenard convection is characterized by the presence of intense coherent structures called plumes. 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.

For historical reasons, the thermal instability of a fluid layer heated from below is called rayleighbenard convection. In all previous studies of the rayleighbenard problem using the modal approach, a particular solution of the continuity equation \1. To demonstrate the main ideas, we study the twodimensional rayleighbenard convection, which serves as a prototype problem. This model of thermal convection is a paradigm for nonlinear and chaotic dynamics, pattern formation and fully developed turbulence kadano.

Rayleighbenard convection as a model of a nonlinear system. Nonoberbeckboussinesq effects and the dynamics of the large scale convection roll are addressed as well. Large and smallscale dynamics in turbulent rayleigh. Mechanisms of instability in rayleigh benard convection a thesis presented to the academic faculty by adam c. In all previous studies of the rayleigh benard problem using the modal approach, a particular solution of the continuity equation \1. Thermal boundary layer near roughnesses in turbulent. 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. Vertical walls are adiabatic, while horizontal surfaces are assumed to be isothermal and held at different temperatures. Identification, decomposition and analysis of dynamic large. Mechanisms of extensive spatiotemporal chaos in rayleigh. If this is the first time you use this feature, you will be asked to authorise cambridge core to connect with your account. Rayleigh benard thermal convection 3d simulation with lbm.

The following matlab project contains the source code and matlab examples used for rayleigh benard convection. This nonequilibrium crystallography was and still is a rich source of inspiration, as i show. Rayleigh benard convection in matlab download free open. For ra rac, but not too large, a regular structure of convection rolls forms. As a prototype of problem and to demonstrate the main ideas, we study the twodimensional rayleigh benard convection. Heat transfer and large scale dynamics in turbulent. Dynamics and structure in the physical space article pdf available in communications in mathematical sciences 53 november 2006 with 181 reads how we measure reads. 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. A rayleigh benard convective instability study using energy. Identification, decomposition and analysis of dynamic. Mathematik, freie universitat berlin, arnimallee 6, d14195 berlin, germany 2 max planck institute f. 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. Numerical simulation of highly turbulent twodimensional rayleighbenard convection.

Rayleighbenard convection is a type of natural convection where fluid motion is driven by vertical thermal gradients, i. Rayleighbenard convection physics courses uc san diego. Coherence of temperature and velocity superstructures in. Transition from convection rolls to largescale cellular structures in turbulent. The impact of benard s discovery on 20th century physics is crucial to any modern research area such as fluid dynamics, nonlinear dynamics, and nonequilibrium thermodynamics, just to name a few. Mechanisms of instability in rayleighbenard convection a thesis presented to the academic faculty by adam c. Examples of spatiotemporal chaos are examined because this. It is a model system with simple boundary conditions to study a range of interesting problems of turbulence, such as turbulent heat transport, boundary layer dynamics, largescale flow structures and. Structure in the physical space tian ma and shouhong wang abstract. Rayleighb enard convection, thirty years of experimental. 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.

Effect of sidewall on heat transfer and flow structure in rayleighbenard convection volume 881 zhenhua wan, ping wei, roberto verzicco, detlef lohse, guenter ahlers, richard j. In the case of the pure rayleighbenard convection, the field of investigation is so. Homogeneous rayleighbenard convection scaling, heat transport and structures e. The e ect of thermal noise on the bifurcation to convection is discussed because experimental work on this is quite recent and as yet incomplete. Busse 1972 pointed out that it would be surprising if. The impact of benards discovery on 20th century physics is crucial to any modern research area such as fluid dynamics, nonlinear dynamics, and nonequilibrium thermodynamics, just to name a few. Transition from convection rolls to largescale cellular. The main objective of this article is part of a research program to link the dynamics of. Rayleighbenard convection has been widely studied both experimentally and theoretically 8 9 10. Title transition from convection rolls to largescale cellular structures in turbulent rayleighbenard convection in a liquid metal layer authors akashi, megumi.

Large eddy simulation on rayleighbenard convection of cold. Plume dynamics in rotating rayleighbenard convection. Rayleighbenard problem is a classic problem of fluid dynamics. Paul manneville, in dissipative structures and weak turbulence, 1990. This problem has been studied by many researchers during the past several decades owing to their wide applications in a number of industrial processes, such as heat exchangers, electronic cooling. Thermal boundary layer near roughnesses in turbulent rayleigh. With an overdrive account, you can save your favorite libraries for ataglance information about availability. In reading about this type of convection see rayleighbenard convection. Effect of sidewall on heat transfer and flow structure in.

Rayleighbenard convection by alexander v getling overdrive. Issues for future research 530 acknowledgments 531 references 531 i. We report bursting dynamics in a parametrically driven rayleighbenard convection rbc model of low prandtlnumber fluids with freeslip boundary conditions. Rayleighbenard convection, bifurcated attractor, basin of attraction, structural stability, roll structure. Structure of plumes in turbulent rayleigh benard convection. Flows of this type, known as rayleighbenard convection, show important features of behaviour inherent not only in various hydrodynamicinstability phenomena but also in nonlinear pattern.

Rayleighbenard convection, thirty years of experimental. Rayleighbenard convection advanced series in nonlinear. In these lectures we derive mostly the equations of viscous fluid dynamics. Dynamics of spatiotemporal cellular structures henri. Basic types of convectiveflow structures rayleighbenard. A model for nearwall dynamics in turbulent rayleighbenard. Nonlinear bifurcations to timedependent rayleighbenard. The visible quantity is the temperature of the fluid, where red and blue indicate hot and cold fluid, respectively.

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 study exclusively focuses on the structures that from when the rbc geometry is a cylinder. Diffusion maps embedding and transition matrix analysis of. Benard convectionthe problem of a fluid heated from below. Flows of this type, known as rayleighb nard convection, show important features of behaviour inherent not only in various hydrodynamicinstability phenomena but also in nonlinear patternforming processes in other contexts. Rbc plays an important role in a large range of phenomena in geophysics. Horizontal structures of velocity and temperature boundary layers in twodimensional numerical turbulent rayleighbenard convection phys. A model for nearwall dynamics in turbulent rayleigh. 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.

To account for the results, we generalize the grossmannlohse theory for traditional rb convections grossmann and lohse. Hot red fluid rises from the hot bottom plate while cold blue fluid falls down. Dynamics and selforganisation, am fassberg 17, d37077 gottingen, germany 3 max planckuniversity twente center for complex fluid dynamics, gottingen, germany. Jun 18, 2014 numerical simulation of highly turbulent twodimensional rayleigh benard convection. Getling i formed the impression that the primary topic really was rayleighbenard convection itself. If the address matches an existing account you will receive an email with instructions to reset your password. Building on this we solve the equations governing the dynamics of the nonlinear system using a pseudospectral numerical method.

187 1269 1474 579 1317 577 1546 969 842 1195 822 603 1397 1145 1532 708 949 1133 400 487 272 1429 468 904 1620 176 1211 684 1243 232 1553 551 489 852 395 1481 793 558 80 1304 571 823