Water-based suspensions of Al2O3 nanoparticles and MEPCM particles on convection effectiveness in a circular tube

The thermal performance of shell and tube heat exchangers has been enhanced with the use of different techniques. Air bubble injection is one such promising and inexpensive technique that enhances the heat transfer characteristics inside shell and tube heat exchanger by creating turbulence in the flowing fluid. In this paper, experimental study on heat transfer characteristics of shell and tube heat exchanger was done with the injection of air bubbles at the tube inlet and throughout the tube with water based Al2O3 nanofluids i.e. (0.1%v/v and 0.2%v/v). The outcomes obtained for both the concentrations at two distinct injection points were compared with the case when air bubbles were not injected. The outcomes revealed that the heat transfer characteristics enhanced with nanoparticles volumetric concentration and the air bubble injection. The case where air bubbles were injected throughout the tube gave maximum enhancement followed by the cases of injection of air bubbles at the tube inlet and no air bubble injection. Besides this, water based Al2O3 nanofluid with 0.2%v/v of Al2O3 nanoparticles gave more enhancement than Al2O3nanofluid with 0.1%v/v of Al2O3 nanoparticles as the enhancement in the heat transfer characteristics is directly proportional to the volumetric concentration of nanoparticles in the base fluid. The heat transfer rate showed an enhancement of about 25-40% and dimensionless exergy loss showed an enhancement of about 33-43% when air bubbles were injected throughout the tube. Moreover, increment in the heat transfer characteristics was also found due to increase in the temperature of the hot fluid keeping the flow rate of both the heat transfer fluids constant.

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Corrigendum: A comprehensive study of the electrically conducting water based CuO and Al2O3 nanoparticles over coupled nanofluid-sheet interface (2016 J. Phys. D: Appl. Phys. 49 045006)

Journal of Physics D Applied Physics ◽

10.1088/1361-6463/ab16bb ◽

2019 ◽

Vol 52 (26) ◽

pp. 269501

Author(s):

R Ahmad

Keyword(s):

Al2o3 Nanoparticles ◽

Electrically Conducting ◽

Water Based ◽

Comprehensive Study

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Flow and Convective Heat Transfer Characteristics of Nanofluids With Various Shapes of Alumina Nanoparticles

ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer, Volume 1 ◽

10.1115/mnhmt2009-18173 ◽

2009 ◽

Cited By ~ 1

Author(s):

Kyo Sik Hwang ◽

Hyo Jun Ha ◽

Seung Hyun Lee ◽

Hyun Jin Kim ◽

Seok Pil Jang ◽

...

Keyword(s):

Heat Transfer ◽

Laminar Flow ◽

Convective Heat Transfer ◽

Flow Regime ◽

Convective Heat ◽

Circular Tube ◽

Al2o3 Nanoparticles ◽

Heat Transfer Characteristics ◽

Laminar Flow Regime ◽

Transfer Characteristics

This paper is to investigate flow and convective heat transfer characteristics of nanofluids with various shapes of Al2O3 nanoparticles flowing through a uniformly heated circular tube under fully developed laminar flow regime. For the purpose, Al2O3 nanofluids of 0.3 Vol.% with sphere, rod, platelet, blade and brick shapes are manufactured by a two-step method. Zeta potential as well as TEM image is experimentally obtained to examine suspension and dispersion characteristics of Al2O3 nanofluids with various shapes. To investigate flow characteristics, the pressure drop of Al2O3 nanofluids with various shapes are measured. In order to investigate convective heat transfer characteristics, the effective thermal conductivities of Al2O3 nanofluids with various shapes, the temperature distribution at the tube surface and the mean temperature of nanofluids at the inlet are measured, respectively. Based on the experimental results, the convective heat transfer coefficient of Al2O3 nanofluids with various shapes is compared with that of pure water and the thermal conductivity of Al2O3 nanofluids with various shapes. Thus, the effect of nanoparticles shape on the flow and convective heat transfer characteristics flowing through a uniformly heated circular tube under fully developed laminar flow regime is experimentally investigated.

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