Spatio-temporal disruption of thermocline by successive laminar vortex pairs in a single tank thermal energy storage

Tinaikar, Aashay and Advaith, S and Chetia, Utpal Kumar and Manu, K V and Basu, Saptarshi (2016) Spatio-temporal disruption of thermocline by successive laminar vortex pairs in a single tank thermal energy storage. In: APPLIED THERMAL ENGINEERING, 109 (B). pp. 924-935.

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Abstract

The stratification efficiency of single tank thermal energy storage is affected by the internal mixing processes; especially in the thermocline region due to disturbances of different kinds. To study the mixing dynamics at the interface, we have conducted detailed numerical and supporting experimental studies for different Atwood numbers (stratification levels). Numerical experiments were conducted with two successive vortex pairs with three different time-lags (short, medium and long). For the short time-lag case, the preliminary vortex pair merges with the ensuing vortex pair. The merged single vortex pair peels back the thermocline layer causing mixing of the hot and cold fluids. The thermocline thickness increases as a result of the entrainment of the cold fluid into the hot fluid. The peeling process continues until buoyant forces leads to plume like structures that penetrate into the lighter fluid. For the medium and large time-lag cases, such merging of vortices was not observed. The vortex pair interacts separately with the thermocline region. The plume structure created by the first vortex pair interacts with the ensuing vortex pair. The altered interface (thermocline) thickness strongly depends on the nature of the vortex-thermocline interaction mechanisms. The thermocline effectiveness decreases consequent to such interactions and have been quantified in details in the current work. (C) 2016 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	APPLIED THERMAL ENGINEERING
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
Additional Information:	Copy right for this article belongs to the PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	07 Jan 2017 09:52
Last Modified:	07 Jan 2017 09:52
URI:	http://eprints.iisc.ac.in/id/eprint/55877

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