Annals of the Assembly for International Heat Transfer Conference 13

ISBN 1-56700-225-0 / CD 1-56700-226-9

Year 2006

W. J. J. Vorster
University of Oxford, Oxford, Oxfordshire, UK

A. M. Korsunsky
University of Oxford, Oxford, Oxfordshire, UK

This study forms a substantial part of the research project being conducted in the field of spray quenching. High heat fluxes obtainable during spray quenching/cooling are widely used in manufacturing, and could be of significant benefit for many other area that range widely from cooling of electronics to nuclear safety to laser dermatological surgery, to name but a few. This article is focused on spray operations used in metals manufacturing processes.
The aims of this study were to conduct experimental spatially and time-resolved measurements of temperature fields in quenched samples, and to deduce and visualise the spatio-temporal variation of the heat flux and heat transfer coefficient in vertical plates of aluminium alloy HS30 (AA6082) subjected to spray quenching with water. The plates were heated to just above 500 °C and then sprayed with pressurised water at room temperature. Infra red (IR) transient thermographs of the specimen surface temperature were collected during experiments and applied as boundary conditions to a 2D inverse numerical model to establish the surface heat flux responsible for the observed temperature distribution. Therefore, transient 2D maps of the heat transfer coefficient distribution on the plate surface were constructed. This is crucial information needed as input into process simulations in order to model and predict accurately material deformation and phase transformations that occur during quench spray processing of metallic components.
Complex interactions between hot metallic surface and spray particles, and the boiling regimes that arise on the plate specimen surface can be studied by analysing the results presented in this paper. Such results provide the basis for more accurate predictions of material properties and residual stress field distribution that arise as a consequence of processing. The new approach provides a substantial improvement over the conventional approach whereby the metallurgical properties of quenched components are estimated by the application of average quench rates to the entire component.

JET-23 pages DOI: 10.1615/IHTC13.p16.220 Download article

Article price - $35.00

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