Heat transfer by using TiO2 nanofluids

This paper reports an experimental study on the heat transfer characteristics of a nanofluid consisting of ZnO/water/ethylene glycol (EG) and TiO2/water/ /ethylene glycol. In this study, the base fluids of ethylene glycol (EG):water (W) with volume fractions of 30:70, 40:60, and 50:50 were prepared, and 0.2 to 1.0 volume fractions of ZnO and TiO2 nanofluids were used as a cold side fluid. The prime objective of this study is to identify the effects of nanofluid concentration and three different hot fluid inlet temperatures viz., 55, 65 and 75?C C on the heat transfer enhancement of cold side fluid. The results are compared with base fluids and the percentage increase of the Nusselt number because of nanoparticle addition is noted both experimentally and theoretically. The results showed that at the hot fluid inlet temperature of 75?C, the increase in the Nusselt number is maximum with volume concentrations of 0.6 and 0.8% for ZnO and TiO2 nanofluids, respectively. The corresponding maximum Nusselt number enhancements are about 11.5 and 21.4%, respectively, for the base fluid volume fraction of 30:70 (EG:W). There is good agreement between the results calculated from experimental values and the correlation.

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Flow boiling heat transfer analysis of Al2O3 and TiO2 nanofluids in horizontal tube using artificial neural network (ANN)

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-019-08674-y ◽

2019 ◽

Vol 139 (5) ◽

pp. 3197-3217 ◽

Cited By ~ 2

Author(s):

Manish Dadhich ◽

Om Shankar Prajapati ◽

Nirupam Rohatgi

Keyword(s):

Neural Network ◽

Heat Transfer ◽

Artificial Neural Network ◽

Boiling Heat Transfer ◽

Flow Boiling ◽

Horizontal Tube ◽

Heat Transfer Analysis ◽

Flow Boiling Heat Transfer ◽

Artificial Neural Network Ann ◽

Tio2 Nanofluids

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Thermal Performance of Hybrid-Inspired Coolant for Radiator Application

Nanomaterials ◽

10.3390/nano10061100 ◽

2020 ◽

Vol 10 (6) ◽

pp. 1100

Author(s):

F. Benedict ◽

Amit Kumar ◽

K. Kadirgama ◽

Hussein A. Mohammed ◽

D. Ramasamy ◽

...

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Heat Capacity ◽

Specific Heat ◽

Specific Heat Capacity ◽

Volume Concentration ◽

The Other ◽

Hybrid Nanofluid ◽

Hybrid Nanofluids ◽

Tio2 Nanofluids

Due to the increasing demand in industrial application, nanofluids have attracted the considerable attention of researchers in recent decades. The addition of nanocellulose (CNC) with water (W) and ethylene glycol (EG) to a coolant for a radiator application exhibits beneficial properties to improve the efficiency of the radiator. The focus of the present work was to investigate the performance of mono or hybrid metal oxide such as Al2O3 and TiO2 with or without plant base-extracted CNC with varying concentrations as a better heat transfer nanofluid in comparison to distilled water as a radiator coolant. The CNC is dispersed in the base fluid of EG and W with a 60:40 ratio. The highest absorption peak was noticed at 0.9% volume concentration of TiO2, Al2O3, CNC, Al2O3/TiO2, and Al2O3/CNC nanofluids which indicates a better stability of the nanofluids’ suspension. Better thermal conductivity improvement was observed for the Al2O3 nanofluids in all mono nanofluids followed by the CNC and TiO2 nanofluids, respectively. The thermal conductivity of the Al2O3/CNC hybrid nanofluids with 0.9% volume concentration was found to be superior than that of the Al2O3/TiO2 hybrid nanofluids. Al2O3/CNC hybrid nanofluid dominates over other mono and hybrid nanofluids in terms of viscosity at all volume concentrations. CNC nanofluids (all volume concentrations) exhibited the highest specific heat capacity than other mono nanofluids. Additionally, in both hybrid nanofluids, Al2O3/CNC showed the lowest specific heat capacity. The optimized volume concentration from the statistical analytical tool was found to be 0.5%. The experimental results show that the heat transfer coefficient, convective heat transfer, Reynolds number and the Nusselt number have a proportional relationship with the volumetric flow rate. Hybrid nanofluids exhibit better thermal conductivity than mono nanofluids. For instance, a better thermal conductivity improvement was shown by the mono Al2O3 nanofluids than the CNC and TiO2 nanofluids. On the other hand, superior thermal conductivity was observed for the Al2O3/CNC hybrid nanofluids compared to the other mono and hybrid ones (Al2O3/TiO2).

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