The effects of thermo-electrically induced convection in alloy solidification
Kao, A., Pericleous, K., Patel, M. and Voller, V. (2008) The effects of thermo-electrically induced convection in alloy solidification. In: Civil-Comp Proceedings. Civil-Comp Press, Stirlingshire, UK. ISBN 978-1-905088-24-9 (Book), 978-1-905088-25-6 (CD-Rom), 978-1-905088-26-3 (Combined Set) ISSN 1759-3433 (doi:10.4203/ccp.89.46)Full text not available from this repository.
The effects of a constant uniform magnetic field on thermoelectric currents during dendritic solidification were investigated using a 2-dimensional enthalpy based numerical model. Using an approximation of the dendrite growing in free space it was found that the resulting Lorentz force generates a circulating flow influencing the solidification pattern. As the magnetic field strength increases it was found that secondary growth on the clockwise side of the primary arm of the dendrite was encouraged, while the anticlockwise side is suppressed due to a reduction in local free energy. The preferred direction of growth rotated in the clockwise sense under an anti-clockwise flow for both the binary alloy and pure material. The tip velociy is significantly increased compared to growth in stagnant flow. This is due to a small recirculation that follows the tip of the dendrite; bringing in colder liquid and lower concentrations of solute. The recirculation being not normally incident on the tip is most likely the cause for the rotation. Grain growth consisting of multiple seeds with the same anisotropy growing in the same plane, gives a competition to release latent heat resulting in stunted growth. The initial growth for each dendrite is very similar to the single seed cases indicating that dendrites must become before the thermoelectric interactions are significant.
|Item Type:||Conference Proceedings|
|Title of Proceedings:||Civil-Comp Proceedings|
|Additional Information:||A summary of this paper is contained in the Proceedings of the Sixth International Conference on Engineering Computational Technology, held in Athens, Greece, 2-5 September 2008. The full length papers are available in electronic format on an accompanying CD-ROM. [ISBN 978-1-905088-24-9 (Book); 978-1-905088-25-6 (CD-Rom); 978-1-905088-26-3 (Combined Set)]|
|Uncontrolled Keywords:||dendritic-growth, MHD, thermoelectricity, enthalpy, undercooling, binary-alloy|
|Subjects:||Q Science > QD Chemistry|
Q Science > QA Mathematics
Q Science > QC Physics
|School / Department / Research Groups:||School of Computing & Mathematical Sciences|
School of Computing & Mathematical Sciences > Department of Computer Systems Technology
School of Computing & Mathematical Sciences > Department of Mathematical Sciences
|Last Modified:||28 Mar 2012 10:50|
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