CFD analysis on natural convective heat transfer of Al₂O₃-gear oil nanolubricant used in HEMM

Abstract

Purpose

The present work aims to numerically investigate the natural convective heat transfer performance of aluminium oxide (Al₂O₃)-gear oil nanolubricant used in heavy earth moving machinery (HEMM).

Design/methodology/approach

Viscosity, density and thermal conductivity of nanolubricants have been experimentally determined. The numerical simulation has been performed by using computational fluid dynamics (CFD) for a cylinder cavity which resembles shape of automatic transmission system of HEMM. The left wall temperature has been maintained at 293 to 313 K, and right wall is at a constant temperature of 283 K. Due to absence of any experimental study on natural convective heat transfer performance of Al₂O₃-gear oil nanolubricant, initially CFD model has been tested for accuracy by comparing experimental, and CFD results for Al₂O₃-water nanofluid has been available in open literature.

Findings

It has been observed that Nusselt number increases with increase in Rayleigh number, but it decreases with increasing particle volume fraction. The gear oil-based nanolubricant is expected to have the better thermal performance in HEMM at higher temperature.

Practical implications

The numerical analysis will help to predict the thermal performance of nanolubricant. The outcome may help the designers, researchers and manufacturers of HEMM.

Originality/value

Most of the previous studies have been limited with base fluid as water, ethylene glycol, etc. in the field of nanofluid. CFD study for thermal performance of Al₂O₃-gear oil nanolubricant is essential before the experimental work. This work is the preliminary stage of application of, nanolubricant for heat transfer.

Citation

Kotia, A. and Ghosh, S.K. (2017), "CFD analysis on natural convective heat transfer of Al₂O₃-gear oil nanolubricant used in HEMM", Industrial Lubrication and Tribology, Vol. 69 No. 5, pp. 673-677. https://doi.org/10.1108/ILT-01-2016-0009