The problem of laminar forced convection flow of nanofluids has been thoroughly investigated for two particular geometrical configurations, namely a uniformly heated tube and a system of parallel, coaxial and heated disks. Numerical results, as obtained for water-γAl 2 O 3 and Ethylene Glycol-γAl 2 O 3 mixtures, have clearly shown that the inclusion of nanoparticles into the base fluids has produced a considerable augmentation of the heat transfer coefficient that clearly increases with an increase of the particle concentration. However, the presence of such particles has also induced drastic effects on the wall shear stress that increases appreciably with the particle loading. Among the mixtures studied, the Ethylene Glycol -γAl 2 O 3 nanofluid appears to offer a better heat transfer enhancement than water- γ/Al 2 O 3 ; it is also the one that has induced more pronounced adverse effects on the wall shear stress. For the case of tube flow, results have also shown that, in general, the heat transfer enhancement also increases considerably with an augmentation of the flow Reynolds number. Correlations have been provided for computing the Nusselt number for the nanofluids considered in terms of the Reynolds and the Prandtl numbers and this for both the thermal boundary conditions considered

Heat transfer enhancement by using nanofluids in forced convection flows

Nanofluids, due to their superior thermal properties, have immense applications in heat transfer process. In view of this, nanofluids, as working fluids in solar thermal systems, have gained importance. This review emphasizes the properties of nanofluids for solar thermal applications as well as typical nanomaterials and analyses experimental and numerical investigations on solar thermal systems utilizing nanofluids along with typical experimental setups and calculation methods used for determination of the performance of nanofluids in the same. The effect of nanoparticles concentration, flowrate, ambient temperature, solar intensity and inlet temperature on the solar thermal system performance utilizing nanofluids is also discussed. Further, challenges occurring during application of nanofluids in solar thermal systems are specified along with recommendations for scaling up of nanofluid-based solar thermal systems.

Performance evaluation of nanofluids in solar thermal and solar photovoltaic systems: A comprehensive review

The fact that some of solid materials with suitable phases possess higher thermal conductivity than liquids gave rise to their utilization in heat transfer processes. Fluids that contain nanopartic...

A Review on Graphene Derivatives-Based Nanofluids: Investigation on Properties and Heat Transfer Characteristics

Nanofluids, due to their superior thermal properties, have immense applications in heat transfer process. In view of this, nanofluids, as working fluids in solar thermal systems, have gained importance. This review emphasizes the properties of nanofluids for solar thermal applications as well as typical nanomaterials and analyses experimental and numerical investigations on solar thermal systems utilizing nanofluids along with typical experimental setups and calculation methods used for determination of the performance of nanofluids in the same. The effect of nanoparticles concentration, flowrate, ambient temperature, solar intensity and inlet temperature on the solar thermal system performance utilizing nanofluids is also discussed. Further, challenges occurring during application of nanofluids in solar thermal systems are specified along with recommendations for scaling up of nanofluid-based solar thermal systems. • Superior thermal and optical properties of nanofluids aid in solar applications. • Nanofluids are applicable in solar collectors, PVT systems and solar stills. • Numerical and experimental investigations prove enhanced performance of nanofluids. • Challenges and recommendations for nanofluid application in solar systems are specified. 

Investigation on preparation of graphene oxide-CuO nanocomposite based nanofluids with the aid of ultrasound assisted method for intensified heat transfer properties

In this study, investigation of convective heat transfer enhancement with the use of CuO–Polyaniline (CuO–PANI) nanocomposite basednanofluid inside vertical helically coiled tube heat exchanger was carried out experimentally. In these experiments, the effects of different parameters such as Reynolds number and volume % of CuO–PANI nanocomposite in nanofluid on the heat transfer coefficient of base fluid have been studied. In order to study the effect of CuO–PANI nanocomposite based nanofluid on heat transfer, CuO nanoparticles loaded in PANI were synthesized in the presence of ultrasound assisted environment at different loading concentration of CuO nanoparticles (1, 3 and 5 wt.%). Then the nanofluids were prepared at different concentrations of CuO–PANI nanocomposite using water as a base fluid. The 1 wt.% CuO–PANI nanocomposite was selected for the heat transfer study for nanofluid concentration in the range of 0.05 to 0.3 volume % and Reynolds number range of was 1080 to 2160 (±5). Around 37 % enhancement in the heat transfer coefficient was observed for 0.2 volume % of 1 wt.% CuO–PANI nanocomposite in the base fluid. In addition, significant enhancement in the heat transfer coefficient was observed with an increase in the Reynolds number and percentage loading of CuO nanoparticle in Polyaniline (PANI).

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Intensified Thermal Conductivity and Convective Heat Transfer of Ultrasonically Prepared CuO-Polyaniline Nanocomposite Based Nanofluids in Helical Coil Heat Exchanger

Abhishek Lanjewar

Papers

Intensified Thermal Conductivity and Convective Heat Transfer of Ultrasonically Prepared CuO-Polyaniline Nanocomposite Based Nanofluids in Helical Coil Heat Exchanger