Journal
POWDER TECHNOLOGY
Volume 345, Issue -, Pages 668-675Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.powtec.2019.01.041
Keywords
Colloidal dispersion; Ultrasound vibration; Stability; Thermal conductivity; Viscosity; Heat transfer
Categories
Funding
- High Impact Research MoE (Ministry of Education Malaysia) [UM.C/625/1/HIR/MoE/ENG/40 (D000040-16001)]
Ask authors/readers for more resources
Owing to the improvements in thermophysical properties, nanofluids are considered advantageous over pure fluids in heat transfer applications. However, these improvements may be regarded as meaningful for applications provided that optimum dispersion of nanoparticles is ensured throughout the process, which mostly depend on preparation technique. In this study, alumina (Al2O3)-water nanofluids of 0.5 vol% were prepared using ultrasonication (up to 5 h) and stored at stationary condition until 30 days. We have evaluated stability as temporal volume fraction by measuring density. Further, thermal conductivity and viscosity were measured, and heat transfer performance was analyzed for the case of fully developed laminar flow inside a tube. All the measurements were conducted at 25 degrees C temperature. Results revealed that longer ultrasonication reduces sedimentation of nanoparticles and hence, increases stability of nanofluids. Thermal conductivity increased, while viscosity decreased with increasing sonication time. Moreover, these thermophysical properties decreased with storage periods. It was observed, until 30 days of storage that ultrasonication process for different durations induced significant changes in viscosity, although those in thermal conductivity was not as pronounced. All the prepared samples were determined beneficial as heat transfer fluids over water, even after 30 days from preparation. (C) 2019 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available