ISSN: 1546-962X
CODEN: JAIOAD
Published Online: 6 March 2009
Page Count: 9

Severity of Quenching and Kinetics of Wetting of Nanofluids and Vegetable Oils

Jagannath, Vaishali
National Institute of Technology Karnataka, Mangalore, Karnataka State

Prabhu, K. Narayan
National Institute of Technology Karnataka, Mangalore, Karnataka State


(Received 15 April 2008; accepted 4 February 2009)

Abstract

In the present work, the suitability of vegetable oil blends with mineral oil and alumina based nanofluids as quench media for industrial heat treatment was investigated. Sunflower oil, palm oil, and mineral oil were used for preparing the blends. Alumina based nanofluids of varying concentrations ranging from 0.01–4 % were used. The size of alumina particles was about 50 nm. The severity of quenching and heat transfer coefficients were estimated during quenching of copper probes. Heat transfer coefficients were estimated using a lumped heat capacitance model. The static contact angle was measured on copper substrates having a surface texture similar to the probes used for estimation of heat transfer coefficients. A dynamic contact angle analyzer was used for this purpose. The measured contact angles of nanofluids on copper were high compared to oils, indicating poor wetting by quench media that are polar in nature. Wetting characteristics had a significant effect on heat transfer coefficients estimated during quenching.

Keywords:
quenching, nanofluids, vegetable oils, wetting, heat transfer coefficient

Paper ID: JAI101800
DOI: 10.1520/JAI101800
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