Investigating the effect of suspensions nanostructure on the thermophysical properties of nanofluids

Waka Tesfai, Pawan K. Singh, Salim J.S. Masharqa, Tewfik Souier, Matteo Chiesa, Youssef Shatilla

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The effect of fractal dimensions and Feret diameter of aggregated nanoparticle on predicting the thermophysical properties of nanofluids is demonstrated. The fractal dimensions and Feret diameter distributions of particle agglomerates are quantified from scanning electron and probe microscope imaging of yttria nanofluids. The results are compared with the fractal dimensions calculated by fitting the rheological properties of yttria nanofluids against the modified Krieger-Dougherty model. Nanofluids of less than 1 vol. % particle loading are found to have fractal dimensions of below 1.8, which is typical for diffusion controlled cluster formation. By contrast, an increase in the particle loading increases the fractal dimension to 2.0-2.2. The fractal dimensions obtained from both methods are employed to predict the thermal conductivity of the nanofluids using the modified Maxwell-Garnet (M-G) model. The prediction from rheology is found inadequate and might lead up to 8% error in thermal conductivity for an improper choice of aspect ratio. Nevertheless, the prediction of the modified M-G model from the imaging is found to agree well with the experimentally observed effective thermal conductivity of the nanofluids. In addition, this study opens a new window on the study of aggregate kinetics, which is critical in tuning the properties of multiphase systems.

Original languageEnglish
Article number114315
JournalJournal of Applied Physics
Volume112
Issue number11
DOIs
Publication statusPublished - Dec 1 2012

Fingerprint

thermophysical properties
fractals
thermal conductivity
garnets
electron probes
predictions
rheology
aspect ratio
electron microscopes
tuning
microscopes
nanoparticles
scanning
kinetics

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Investigating the effect of suspensions nanostructure on the thermophysical properties of nanofluids. / Tesfai, Waka; Singh, Pawan K.; Masharqa, Salim J.S.; Souier, Tewfik; Chiesa, Matteo; Shatilla, Youssef.

In: Journal of Applied Physics, Vol. 112, No. 11, 114315, 01.12.2012.

Research output: Contribution to journalArticle

Tesfai, Waka ; Singh, Pawan K. ; Masharqa, Salim J.S. ; Souier, Tewfik ; Chiesa, Matteo ; Shatilla, Youssef. / Investigating the effect of suspensions nanostructure on the thermophysical properties of nanofluids. In: Journal of Applied Physics. 2012 ; Vol. 112, No. 11.
@article{145d1184b26c4ff685c7672d0f993d38,
title = "Investigating the effect of suspensions nanostructure on the thermophysical properties of nanofluids",
abstract = "The effect of fractal dimensions and Feret diameter of aggregated nanoparticle on predicting the thermophysical properties of nanofluids is demonstrated. The fractal dimensions and Feret diameter distributions of particle agglomerates are quantified from scanning electron and probe microscope imaging of yttria nanofluids. The results are compared with the fractal dimensions calculated by fitting the rheological properties of yttria nanofluids against the modified Krieger-Dougherty model. Nanofluids of less than 1 vol. {\%} particle loading are found to have fractal dimensions of below 1.8, which is typical for diffusion controlled cluster formation. By contrast, an increase in the particle loading increases the fractal dimension to 2.0-2.2. The fractal dimensions obtained from both methods are employed to predict the thermal conductivity of the nanofluids using the modified Maxwell-Garnet (M-G) model. The prediction from rheology is found inadequate and might lead up to 8{\%} error in thermal conductivity for an improper choice of aspect ratio. Nevertheless, the prediction of the modified M-G model from the imaging is found to agree well with the experimentally observed effective thermal conductivity of the nanofluids. In addition, this study opens a new window on the study of aggregate kinetics, which is critical in tuning the properties of multiphase systems.",
author = "Waka Tesfai and Singh, {Pawan K.} and Masharqa, {Salim J.S.} and Tewfik Souier and Matteo Chiesa and Youssef Shatilla",
year = "2012",
month = "12",
day = "1",
doi = "10.1063/1.4768454",
language = "English",
volume = "112",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "American Institute of Physics Publising LLC",
number = "11",

}

TY - JOUR

T1 - Investigating the effect of suspensions nanostructure on the thermophysical properties of nanofluids

AU - Tesfai, Waka

AU - Singh, Pawan K.

AU - Masharqa, Salim J.S.

AU - Souier, Tewfik

AU - Chiesa, Matteo

AU - Shatilla, Youssef

PY - 2012/12/1

Y1 - 2012/12/1

N2 - The effect of fractal dimensions and Feret diameter of aggregated nanoparticle on predicting the thermophysical properties of nanofluids is demonstrated. The fractal dimensions and Feret diameter distributions of particle agglomerates are quantified from scanning electron and probe microscope imaging of yttria nanofluids. The results are compared with the fractal dimensions calculated by fitting the rheological properties of yttria nanofluids against the modified Krieger-Dougherty model. Nanofluids of less than 1 vol. % particle loading are found to have fractal dimensions of below 1.8, which is typical for diffusion controlled cluster formation. By contrast, an increase in the particle loading increases the fractal dimension to 2.0-2.2. The fractal dimensions obtained from both methods are employed to predict the thermal conductivity of the nanofluids using the modified Maxwell-Garnet (M-G) model. The prediction from rheology is found inadequate and might lead up to 8% error in thermal conductivity for an improper choice of aspect ratio. Nevertheless, the prediction of the modified M-G model from the imaging is found to agree well with the experimentally observed effective thermal conductivity of the nanofluids. In addition, this study opens a new window on the study of aggregate kinetics, which is critical in tuning the properties of multiphase systems.

AB - The effect of fractal dimensions and Feret diameter of aggregated nanoparticle on predicting the thermophysical properties of nanofluids is demonstrated. The fractal dimensions and Feret diameter distributions of particle agglomerates are quantified from scanning electron and probe microscope imaging of yttria nanofluids. The results are compared with the fractal dimensions calculated by fitting the rheological properties of yttria nanofluids against the modified Krieger-Dougherty model. Nanofluids of less than 1 vol. % particle loading are found to have fractal dimensions of below 1.8, which is typical for diffusion controlled cluster formation. By contrast, an increase in the particle loading increases the fractal dimension to 2.0-2.2. The fractal dimensions obtained from both methods are employed to predict the thermal conductivity of the nanofluids using the modified Maxwell-Garnet (M-G) model. The prediction from rheology is found inadequate and might lead up to 8% error in thermal conductivity for an improper choice of aspect ratio. Nevertheless, the prediction of the modified M-G model from the imaging is found to agree well with the experimentally observed effective thermal conductivity of the nanofluids. In addition, this study opens a new window on the study of aggregate kinetics, which is critical in tuning the properties of multiphase systems.

UR - http://www.scopus.com/inward/record.url?scp=84871216996&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84871216996&partnerID=8YFLogxK

U2 - 10.1063/1.4768454

DO - 10.1063/1.4768454

M3 - Article

VL - 112

JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

IS - 11

M1 - 114315

ER -