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.