Effect of natural convection on oscillating flow in a pipe with cryogenic temperature difference across the ends

Ashwin, TR and Narasimham, GSVL and Jacob, Subhash (2012) Effect of natural convection on oscillating flow in a pipe with cryogenic temperature difference across the ends. In: International Journal of Heat and Mass Transfer, 55 (4). pp. 680-694.

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Abstract

The effect of natural convection on the oscillatory flow in an open-ended pipe driven by a timewise sinusoidally varying pressure at one end and subjected to an ambient-to-cryogenic temperature difference across the ends, is numerically studied. Conjugate effects arising out of the interaction of oscillatory flow with heat conduction in the pipe wall are taken into account by considering a finite thickness wall with an insulated exterior surface. Two cases, namely, one with natural convection acting downwards and the other, with natural convection acting upwards, are considered. The full set of compressible flow equations with axissymmetry are solved using a pressure correction algorithm. Parametric studies are conducted with frequencies in the range 5-15 Hz for an end-to-end temperature difference of 200 and 50 K. Results are obtained for the variation of velocity, temperature. Nusselt number and the phase relationship between mass flow rate and temperature. It is found that the Rayleigh number has a minimal effect on the time averaged Nusselt number and phase angle. However, it does influence the local variation of velocity and Nusselt number over one cycle. The natural convection and pressure amplitude have influence on the energy flow through the gas and solid. (C) 2011 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	International Journal of Heat and Mass Transfer
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Natural convection;Oscillating flow;Conjugate conduction
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering Division of Physical & Mathematical Sciences > Centre for Cryogenic Technology
Date Deposited:	04 Apr 2012 09:49
Last Modified:	04 Apr 2012 09:49
URI:	http://eprints.iisc.ac.in/id/eprint/44177

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