Rheological and flow characteristics of nanofluids

Influence of electroviscous effects and particle agglomeration

Anoop Baby, S. Kabelac, T. Sundararajan, Sarit K. Das

Research output: Contribution to journalArticle

169 Citations (Scopus)

Abstract

Nanofluids have shown remarkable attraction in heat transfer community due to its reported enhanced thermal properties. One factor which can restrict nanofluids in heat transfer application is the increased viscosity value (compared to classical predictions). Particle aggregation occurring was the major reason for this observation. Even though majority of the aqueous nanofluids prepared in literature were stabilized electrostatically by adjusting the pH, studies on the effect of the electrical double layer thus created and its influence on viscosity increase has not been investigated for these nanofluids so far. Thus, in the present paper, rheological properties of alumina-water nanofluids, which are electrostatically stabilized, are measured and the increase in suspension viscosity due to presence of this electrical double layer causing additional electroviscous effects is brought out. Based on dynamic light scattering studies, particle agglomeration and its subsequent effect in increasing the viscosity of alumina-ethylene glycol nanofluid, where electroviscous effects are absent, are also considered. It is noted that the understanding of electroviscous effect is equally important as understanding the particle agglomeration effect and understanding both the effects is central to revealing the physics of nanofluid rheology. Further, hydrodynamic experiments are made, which show that nanofluids behaves almost like a homogeneous fluids under flow conditions, and by knowing their properties, such as viscosity and density, pressure drop can be predicted.

Original languageEnglish
Article number034909
JournalJournal of Applied Physics
Volume106
Issue number3
DOIs
Publication statusPublished - 2009
Externally publishedYes

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flow characteristics
agglomeration
viscosity
aluminum oxides
heat transfer
pressure drop
rheology
attraction
glycols
ethylene
light scattering
thermodynamic properties
adjusting
hydrodynamics
physics
fluids
predictions
water

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Rheological and flow characteristics of nanofluids : Influence of electroviscous effects and particle agglomeration. / Baby, Anoop; Kabelac, S.; Sundararajan, T.; Das, Sarit K.

In: Journal of Applied Physics, Vol. 106, No. 3, 034909, 2009.

Research output: Contribution to journalArticle

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