Numerical Heat Transfer and Pressure Drop Studies of Turbulent Al₂O₃ - Ethylene Glycol/Water Nanofluid Flow in an Automotive Radiator Tube

Abstract:

Automotive radiators use flattened tubes within which Ethylene Glycol (EG) and Water (W) based nanofluids flow to enhance the heat transfer. Computations were carried out to understand the flow and thermal characteristics of the Aluminium oxide based nanofluids, with EG:W ratio of 60:40 as the base fluid, flowing inside a flattened tube. The flow was maintained in the turbulent regime with the Reynolds number (Re) ranging from 5,000 to 14,000.Investigations were carried out for nano particle concentrations (φ) varying from 1% to 5% of the base fluid by volume. Computations were also carried out for a circular tube to study the influence of tube shape. The nanofluid with φ = 5% increased the Nusselt number values by 40% for the flattened tubes compared to the base fluid at Re =14,000. These estimates are done at constant flow Reynolds number in-line with literature, which necessitated increased inlet velocity, which meant increased pumping power. Pumping power increased with increase in φ and Re. For a constant pumping power per unit length (P_p) of 5W/m the values of average heat transfer coefficient () decreases with increase in φ. The values of for the 2% and 5% nano fluid were lower than the base fluid by 6% and 23.8% respectively. Nanofluid with φ = 1% alone showed a 1.2% higher value than the base fluid indicating the need of further exploration of φ in a closer range.

• Periodical: Applied Mechanics and Materials (Volume 787)
• Pages: 152-156
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.787.152
• Online since: August 2015
• Authors: N. Mohanrajhu*, K. Purushothaman, N. Kulasekharan
• Keywords: CFD, Flattened Tube, Heat Transfer, Nanofluid, Radiator, Turbulent Flow

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