ISSN: 1546-962X
CODEN: JAIOAD
Published Online: 16 May 2007
Page Count: 11

Effect of Geometry on the Melting Rates of Iron Rods Burning in High Pressure Oxygen

Suvorovs, Terese
Postgraduate Students and Senior LecturerFaculty of Built Envinronment and Engineering, School of Engineering Systems, Queensland University of Technology, Gardens Point, QLD

Ward, Nicholas R.
Postgraduate Students and Senior LecturerFaculty of Built Envinronment and Engineering, School of Engineering Systems, Queensland University of Technology, Gardens Point, QLD

Steinberg, Theodore A.
Postgraduate Students and Senior LecturerFaculty of Built Envinronment and Engineering, School of Engineering Systems, Queensland University of Technology, Gardens Point, QLD

Wilson, Richard
Senior Lecturer, School of Mathematics, The University of Queensland, St. Lucia, QLD

(Received 17 January 2007; accepted 28 March 2007)

Abstract

The effect of sample geometry on the melting rates of burning iron rods was assessed. Promoted-ignition tests were conducted with rods having cylindrical, rectangular, and triangular cross-sectional shapes over a range of cross-sectional areas. The regression rate of the melting interface (RRMI) was assessed using a statistical approach which enabled the quantification of confidence levels for the observed differences in RRMI. Statistically significant differences in RRMI were observed for rods with the same cross-sectional area but different cross-sectional shape. The magnitude of the proportional difference in RRMI increased with the cross-sectional area. Triangular rods had the highest RRMI, followed by rectangular rods, and then cylindrical rods. The dependence of RRMI on rod shape is shown to relate to the action of molten metal at corners. The corners of the rectangular and triangular rods melted faster than the faces due to their locally higher surface area to volume ratios. This phenomenon altered the attachment geometry between liquid and solid phases, increasing the surface area available for heat transfer, causing faster melting. Findings relating to the application of standard flammability test results in industrial situations are also presented.

Keywords:
geometry, statistical method, promoted-ignition, oxygen, mild steel, standard test

Paper ID: JAI101004
DOI: 10.1520/JAI101004
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