Experimental investigation of thermal conductivity and dynamic viscosity on nanoparticle mixture ratios of TiO2-SiO2 nanofluids. (January 2018)

• Record Type: Journal Article
• Authors: Hamid, K. Abdul; Azmi, W.H.; Nabil, M.F.; Mamat, Rizalman; Sharma, K.V.
• Is Part Of: International journal of heat and mass transfer. Volume 116(2018)
• Page Start: 1143
• Page End: 1152
• Publication Date: 2018-01
• Subjects: Thermal conductivity -- Dynamic viscosity -- TiO2-SiO2 nanofluids -- Water-ethylene glycol mixture -- Mixture ratio; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2017.09.087
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: Measurement of thermal conductivity and viscosity for TiO2 -SiO2 nanofluids. Measurement are undertaken for different TiO2 -SiO2 nanoparticle mixture ratios. The maximum enhancement of thermal conductivity was 16% for 20:80 mixture ratio. Dynamic viscosity for all mixture ratios is always lower than 50:50 mixture ratio. The TiO2 -SiO2 nanofluids behaved better properties compared to single nanofluids. Abstract: In recent years, research is focused on enhancing the thermo-physical properties of single component nanofluids. Hence, the hybrid or composite nanofluids are developed to enhance the heat transfer performance. The thermo-physical properties of TiO2 -SiO2 nanoparticles suspended in a base fluid of water (W) and ethylene glycol (EG) mixture with 60:40 vol ratio are investigated. The experiments were conducted for 1.0% volume concentration of TiO2 -SiO2 nanofluids with different mixture ratios of 20:80, 40:60, 50:50, 60:40 and 80:20. The measurements of thermal conductivity and dynamic viscosity were performed in the temperature range of 30–80 °C by using KD2 Pro Thermal Properties Analyzer and Brookfield LVDV III Ultra Rheometer respectively. The highest thermal conductivity for TiO2 -SiO2 nanofluid was obtained with a ratio of 20:80 and the maximum enhancement exceeded up to 16% higher than the base fluids. The nanofluids with a ratio of 50:50 provided the lowest effective thermal conductivity. Meanwhile, the dynamic viscosity variation for all mixture ratios is always lower than the ones with a ratio of 50:50. The properties enhancement ratio suggests that TiO2 -SiO2 nanofluid with 1.0% volume concentration will aid the heat transfer for all mixture ratios except for the ratio of 50:50. As a conclusion, the optimum mixture ratios for TiO2 -SiO2 nanofluids are attained with 40:60 and 80:20 ratios where the combination of enhancement in thermal conductivity and dynamic viscosity had more advantages to heat transfer as compared to other ratios.