Hybrid nanofluids preparation, thermal properties, heat transfer and friction factor – A review

The additives of solid nanoparticles to liquids are significant enhancement of heat transfer and hydrodynamic flow. In this study, the thermal properties of three types of nanoparticles (Al2O3, TiO2, and SiO2) dispersed in water as a base fluid were measured experimentally. Forced convection heat transfer turbulent flow inside heated flat tube was numerically simulated. The heat flux around flat tube is 5000 W/m2and Reynolds number is in the range of5×103to50×103. CFD model by finite volume method used commercial software to find hydrodynamic and heat transfer coefficient. Simulation study concluded that the thermal properties measured and Reynolds number as input and friction factor and Nusselt number as output parameters. Data measured showed that thermal conductivity and viscosity increase with increasing the volume concentration of nanofluids with maximum deviation 19% and 6%, respectively. Simulation results concluded that the friction factor and Nusselt number increase with increasing the volume concentration. On the other hand, the flat tube enhances heat transfer and decreases pressure drop by 6% and −4%, respectively, as compared with circular tube. Comparison of numerical analysis with experimental data available showed good agreement with deviation not more than 2%.

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Thermal Efficiency, Heat Transfer, and Friction Factor Analyses of MWCNT + Fe3O4/Water Hybrid Nanofluids in a Solar Flat Plate Collector under Thermosyphon Condition

Processes ◽

10.3390/pr9010180 ◽

2021 ◽

Vol 9 (1) ◽

pp. 180 ◽

Cited By ~ 1

Author(s):

Bahaa Saleh ◽

Lingala Syam Sundar

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Carbon Nanotubes ◽

Friction Factor ◽

Thermal Efficiency ◽

Volume Concentration ◽

Multi Walled Carbon Nanotubes ◽

Hybrid Nanofluids ◽

Flat Plate Collector ◽

Walled Carbon Nanotubes

The heat transfer, friction factor, and collector efficiency are estimated experimentally for multi-walled carbon nanotubes+Fe3O4 hybrid nanofluid flows in a solar flat plate collector under thermosyphon circulation. The combined technique of in-situ growth and chemical coprecipitation was utilized to synthesize the multi-walled carbon nanotubes+Fe3O4 hybrid nanoparticles. The experiments were carried out at volume flow rates from 0.1 to 0.75 L/min and various concentrations from 0.05% to 0.3%. The viscosity and thermal conductivity of the hybrid nanofluids were experimentally measured at different temperatures and concentrations. Due to the improved thermophysical properties of the hybrid nanofluids, the collector achieved better thermal efficiency. Results show that the maximum thermal conductivity and viscosity enhancements are 28.46% and 50.4% at 0.3% volume concentration and 60 °C compared to water data. The Nusselt number, heat transfer coefficient, and friction factor are augmented by 18.68%, 39.22%, and 18.91% at 0.3% volume concentration and 60 °C over water data at the maximum solar radiation. The collector thermal efficiency improved by 28.09% at 0.3 vol. % at 13:00 h daytime and a Reynolds number of 1413 over water data. Empirical correlations were developed for friction factor and Nusselt number.

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Heat transfer and friction factor of nanodiamond-nickel hybrid nanofluids flow in a tube with longitudinal strip inserts

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2017.12.096 ◽

2018 ◽

Vol 121 ◽

pp. 390-401 ◽

Cited By ~ 14

Author(s):

L. Syam Sundar ◽

Manoj K. Singh ◽

Antonio C.M. Sousa

Keyword(s):

Heat Transfer ◽

Friction Factor ◽

Longitudinal Strip ◽

Hybrid Nanofluids

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Numerical Study of Heat Transfer Enhancement for Mono and Hybrid Nanofluids Flow in a Straight Pipe

CFD letters ◽

10.37934/cfdl.13.2.4961 ◽

2021 ◽

Vol 13 (2) ◽

pp. 49-61

Author(s):

Azraf Azman ◽

Mohd Zamri Yusoff ◽

Azfarizal Mukhtar ◽

Prem Gunnasegaran ◽

Nasri A. Hamid ◽

...

Keyword(s):

Heat Transfer ◽

Heat Transfer Enhancement ◽

Friction Factor ◽

Numerical Study ◽

Reynold Number ◽

Inlet Temperature ◽

Hybrid Nanofluid ◽

Transfer Enhancement ◽

Straight Pipe ◽

Hybrid Nanofluids

In recent years, there has been an increasing interest in heat transfer enhancement using nanofluids in channels due to current devices become smaller and more compact and are expected to perform better. Thus, we attempt to introduce hybrid nanofluids flow in a straight pipe using Ansys Fluent software. The simulation was prepared with certain specific parameters such as the hydraulic diameter is set at 10mm, the flow is a continuum, the Reynold number in the range of 5000 to 30000, k-e turbulent model used in this simulation, the inlet temperature 297 K, and the uniform temperature along the pipe at 313 K. This study was carried out on Al2O3+Cu / water hybrid nanofluids to analyse the thermal improvement and friction factor of nanofluids occur in a straight pipe. Then, the numerical results obtained were compared between mono and hybrid nanofluids. It was found that the mono nanofluids at 1% and 4% indicate a significant increase in Nusselt number at 17% and 24% respectively and hybrid nanofluid increase at 2% to 5.6% compared to base fluid. Whereas the friction factor remains similar for all the nanofluids. However, the performance evaluation criterion (PEC) has shown that hybrid nanofluids remain lower than mono nanofluids.

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Phase Change Thermal Diode Using Al2O3-Cu/Water Hybrid Nanofluids for Thermal Rectification Enhancement

ASME 2020 Power Conference ◽

10.1115/power2020-16278 ◽

2020 ◽

Author(s):

M. Y. Wong ◽

C. Y. Tso ◽

T. C. Ho

Keyword(s):

Heat Transfer ◽

Thermal Properties ◽

Phase Change ◽

Storage Systems ◽

Thermal Storage ◽

Solar Thermal ◽

Working Fluid ◽

Hybrid Nanofluid ◽

Thermal Rectification ◽

Hybrid Nanofluids

Abstract A thermal diode, a device to manipulate the heat flow in different directions, is useful in various thermal systems, such as solar thermal storage systems. It is noted that the performance of phase change thermal diodes shows the highest thermal rectification performances in the literature. The performances of the phase change thermal diode can be further improved by utilizing a working fluid with enhanced thermal properties. Since hybrid nanofluids are proven to have better thermal properties than the base fluid (i.e. water), in this study, a thermal diode using Al2O3-Cu/water hybrid nanofluid is fabricated and tested to investigate the feasibility of using hybrid nanofluid to enhance the performance of the thermal diode. The heat transfer and thermal rectification performances of the thermal diode using Al2O3-Cu/water hybrid nanofluid are compared experimentally, to a thermal diode using water. The effect of temperature on the heat transfer and thermal rectification performances of the thermal diode is also examined. The results indicate that the effective thermal conductivity in the forward direction and the diodicity of the thermal diode using Al2O3-Cu/water hybrid nanofluid are improved by 42.4% and 30.8%, respectively, compared to that of the thermal diode using water. The findings not only reveal a new direction for future research in enhancement of the thermal rectification performance of the phase change thermal diode but also provide an alternative research path for improving the performance of existing solar thermal storage systems.

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Heat Transfer Enhancement of Low Volume Concentration of Carbon Nanotube-Fe3O4/Water Hybrid Nanofluids in a Tube With Twisted Tape Inserts Under Turbulent Flow

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4029622 ◽

2015 ◽

Vol 7 (2) ◽

Cited By ~ 30

Author(s):

L. Syam Sundar ◽

Antonio C. M. Sousa ◽

Manoj Kumar Singh

Keyword(s):

Heat Transfer ◽

Reynolds Number ◽

Nusselt Number ◽

Carbon Nanotube ◽

Friction Factor ◽

Base Fluid ◽

Twisted Tape ◽

Distilled Water ◽

Flow Through ◽

Hybrid Nanofluids

In this paper, it is estimated the heat transfer coefficient and friction factor for fully developed turbulent flow of carbon nanotube (CNT)-Fe3O4/water hybrid nanofluids flow through a tube with twisted tape inserts at constant heat flux conditions. The nanocomposite of CNT-Fe3O4 was prepared by in situ method; which contains dispersion of carboxylated-CNTs in distilled water followed by mixing of ferrous chloride and ferric chloride in the molar ratio of 2:1. Sodium hydroxide was used as reducing agent to form CNT-Fe3O4 nanocomposite. The detailed surface morphology and magnetic properties were performed by X-ray diffraction and scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). The stable hybrid nanofluids were prepared by dispersing nanocomposite in distilled water, and the heat transfer and friction factor experiments were conducted for particle volume concentrations of 0.1% and 0.3%. The results indicate that a maximum of 31.10% enhancement in Nusselt number with a penalty of 1.18-times increase of pumping power was observed for particle concentration of 0.3% at a Reynolds number of 22,000 as compared to base fluid data. The Nusselt number is further enhanced to 42.51% for 0.3% nanofluid flow through a tube with twisted tape of H/D = 5 at a Reynolds number of 22,000 compared to base fluid data. The empirical correlations were proposed for the estimation of Nusselt number and friction factor to match well with the experimental data.

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