Thermal characterization of a nanofluid comprising nanocrystalline ZrO₂ dispersed in water and ethylene glycol

Abstract

Nanofluids, comprising Y₂O₃-stabilized (partially; 3 mol%) ZrO₂ nanoparticles (up to 2 vol%) dispersed in water and ethylene glycol, were developed. A suitable surfactant and stirring routine ensured uniformity and stability of dispersion. Thermal conductivity ratio of the nanofluids, measured using an indigenously developed thermal comparator device, showed a significant increase of up to 100% with only 1.5 vol% nanoparticles. Furthermore, it was analytically shown that shape factor and aspect ratio significantly influence the effective thermal conductivity ratio of nanofluids with comparable vol% nanoparticles. The study demonstrated that a nanofluid of nano-ZrO₂ dispersed in water and ethylene glycol could be usefully applied in closed-loop single-phase heat transfer conditions, such as in refrigerators or microchannels.

Acknowledgments

MC thanks the All India Council of Technical Education, New Delhi for partial financial support. Similar partial financial support from the Indian Space Research Organisation (ISRO), Bangalore and the Department of Science and Technology, New Delhi (NSTI grant no. SR/S5/NM-04/2005) is also gratefully acknowledged.