Two regimes of flux scaling in axially homogeneous turbulent convection in vertical tube

Pawar, Shashikant S and Arakeri, Jaywant H (2016) Two regimes of flux scaling in axially homogeneous turbulent convection in vertical tube. In: PHYSICAL REVIEW FLUIDS, 1 (4).

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Abstract

From experiments of axially homogeneous turbulent convection in a vertical tube using heat (Prandtl number Pr 6 ) and brine (Pr 600 ) we show that at sufficiently high Rayleigh numbers (Ra-g), the Nusselt number Nu(g) similar to (RagPr)(1/2), which corresponds to the so-called ultimate regime scaling. In heat experiments below certain Rag,however,there is transition to a new regime, Nu(g) similar to (RagPr)(0.3). This transition also seems to exist in earlier reported data for Pr = 1 and Pr 600 , at different Ra-g. However, the transition occurs at a single Grashof number, Gr(gc) 1.6 x10(5) , and unified flux scalings for Pr >= 1 , Nug/Pr similar to Gr(g)(0.3), and Nu(g)/Pr similar to Gr(g)(1/2) can be given for the two regimes.

Item Type:	Journal Article
Publication:	PHYSICAL REVIEW FLUIDS
Additional Information:	Copy right for this article belongs to the AMER PHYSICAL SOC, ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	31 Jan 2017 05:00
Last Modified:	31 Jan 2017 05:00
URI:	http://eprints.iisc.ac.in/id/eprint/55983

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