Investigations on dielectric characteristics of hybrid nanofluids through time and frequency domain spectroscopic measurement

This paper presents investigation on dielectric characteristics of mineral and vegetable oil based hybrid nanofluids at different temperatures by Time and Frequency Domain Spectroscopy. For this purpose, hybrid nanofluids (concentration of 0.1 g/l) are prepared by dispersing the mixture of non-conducting type nanoparticle Al2O3 (Alumina) and semiconducting type nanoparticle TiO2 (Titania) in a certain ratio on either mineral oil or vegetable oil. The dc conductivity and activation energy of the different prepared nanofluids are evaluated based on time domain spectroscopic measurement. Thereafter, frequency domain spectroscopic measurement is conducted at 25 degrees C, 40 degrees C, 50 degrees C, 60 degrees C, 70 degrees C and 80 degrees C on the test samples. Finally, ac breakdown voltage measurement of the nanofluids are conducted to investigate any improvement of the dielectric characteristics. It is observed that, using hybrid nanoparticles in the mineral oil, breakdown voltage can be improved upto 70 % than mineral oil and improvement of the BDV for the case of vegetable oil can be upto 58 %. Viscosity of the nanofluids can be reduced upto 12 % than single nanoparticle based mineral oil. Again, in the case of vegetable oil, viscosity can be reduced upto 5.15 % using hybrid nanoparticle. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

This paper investigates the dielectric characteristics of mineral and vegetable oil based hybrid nanofluids at different temperatures using Time and Frequency Domain Spectroscopy. The results show that using hybrid nanoparticles can significantly improve the breakdown voltage and reduce the viscosity of the nanofluids in both mineral and vegetable oil.