Multifractal nature of plume structure in high Rayleigh number convection

Abstract

The geometrically different plan forms of near wall plume structure in turbulent natural convection, visualised by driving the convection using concentration differences across a membrane, are shown to have a common multifractal spectrum of singularities for Rayleigh numbers in the range $10^{10}-10^{11}$ at Schmidt number of 602. The scaling is seen for a length scale range of $2^5$ and is independent of the Rayleigh number, the flux, the strength and nature of the large scale flow, and the aspect ratio. Similar scaling is observed for the plume structures obtained in the presence of a weak flow across the membrane. This common non trivial spatial scaling is proposed to be due to the same underlying generating process of the near wall plume structures.

arXiv comment11pages, 16 figures Accepted in Journal of Fluid mechanics. Revised version. Added two more figures and related discussion on suggestion of referees

References in corpus (2)

• The multifractal nature of turbulent energy dissipation
• "Clusterization" and intermittency of temperature fluctuations in turbulent convection

Cited by in corpus (5)

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• Statistical and geometrical properties of thermal plumes in turbulent Rayleigh-Bénard convection
• Dynamics of line plumes on horizontal surfaces in turbulent convection
• Scaling and spatial intermittency of thermal dissipation in turbulent convection
• A criterion to detect line plumes from velocity fields in turbulent convection