Journal ArticleDOI
High Rayleigh Number Convection
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TLDR
Turbulent convection exemplifies many of the startling aspects of turbulent flows that have been uncovered in the past two decades, but frequently exhibits a novel twist as discussed by the authors, as in the case of free shear flows, convection can organize into large-scale vortical structures, but these then react back in subtle ways on the boundary layers which ultimately sustain them.Abstract:
Turbulent convection exemplifies many of the startling aspects of turbulent flows that have been uncovered in the past two decades, but frequently exhibits a novel twist. Thus, as in the case of free shear flows, convection can organize into large-scale vortical structures, but these then react back in subtle ways on the boundary layers which ultimately sustain them. Thermal plumes are a coherent mode of heat transport, analogous to boundary layer bursts, yet their overall effect can be surprisingly close to the structureless predictions of mixing length theory. Convection cells are closed, which facilitates their experimental control, but fluctuations never exit and there is a dynamically determined bulk forcing. While the single pass mode characteristic of wind tunnel experiments seems simpler, the convection cell is, in ways to be discussed, more constrained. This review aims to familiarize the turbulence researcher with con vergent lines of investigation in convection and also to remind those working in convection that turbulence is not a new subject. To situate convection within the gamut of other turbulent flows, let us by way of introduction contrast the directions in which convection has developed with research on the turbulent boundary layer. From the onset of convection up to Rayleigh numbers Ra � 1 0 times critical, there is a great wealth of information about flow structures (which can be visualized from above), and their relative stabilities (Busse 198 1 ) . Turbulence, in the sense of many coupled modes, and not just sensitive dependence on initial conditions, can arise for low Ra in large aspect ratioread more
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Journal ArticleDOI
Heat transfer and large scale dynamics in turbulent Rayleigh-Bénard convection
TL;DR: In this article, the Nusselt number and the Reynolds number depend on the Rayleigh number Ra and the Prandtl number Pr, and the thicknesses of the thermal and the kinetic boundary layers scale with Ra and Pr.
Journal ArticleDOI
The phenomenology of small-scale turbulence
TL;DR: In this article, the authors survey the existing work on intermittency, refined similarity hypotheses, anomalous scaling exponents, derivative statistics, and intermittency models, and the structure and kinematics of small-scale structure.
Journal ArticleDOI
Passive Scalars in Turbulent Flows
TL;DR: In this article, the complex morphology of the scalar field is reviewed, and they are related to the intermittency problem and other aspects of passive scalar behavior such as spectrum, probability density function, flux, and variance are also addressed.
Journal ArticleDOI
Scaling in thermal convection: a unifying theory
Siegfried Grossmann,Detlef Lohse +1 more
TL;DR: In this article, a systematic theory for the scaling of the Nusselt number Nu and of the Reynolds number Re in strong Rayleigh-Benard convection is suggested and shown to be compatible with recent experiments.
Journal ArticleDOI
Small-Scale Properties of Turbulent Rayleigh-Bénard Convection
Detlef Lohse,Ke-Qing Xia +1 more
TL;DR: In this article, the properties of the structure functions and other small-scale quantities in turbulent Rayleigh-Benard convection are reviewed from an experimental, theoretical, and numerical point of view.
References
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Journal ArticleDOI
Scaling of hard thermal turbulence in Rayleigh-Bénard convection
Bernard Castaing,Gemunu H. Gunaratne,François Heslot,Leo P. Kadanoff,Albert Libchaber,Stefan Thomae,Xiao-Zhong Wu,Stéphane Zaleski,Gianluigi Zanetti +8 more
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Journal ArticleDOI
Turbulent Thermal Convection at Arbitrary Prandtl Number
TL;DR: The mixing length theory of turbulent thermal convection in a gravitationally unstable fluid is extended to yield the dependence of Nusselt number H/H0 on both Prandtl number σ and Rayleigh number Ra.