ARTICLE:

• Convective Heat Transfer Control Using Magnetic and Electric Fields  download article

George S. Dulikravich
Department of Mechanical and Materials Eng., Florida International University, 10555 West Flagler Street, Miami, Florida 33174, USA

Marcelo J. Colaco
Military Institute of Engineering (IME), Mechanical & Materials Engineering Department (DE/4), Praca General Tiburcio 80, Rio de Janeiro, RJ 22290-270, Brazil

ABSTRACT

A practical approach to non-intrusively controlling electrically conducting melt flow-fields and heat transfer could be achieved by using externally applied magnetic and electric fields. Computational methods are needed to enhance our understanding of this phenomena and its potential in practical industrial processes. In addition, numerical simulation can be used together with optimization to determine distributions of magnets and/or electrodes on the walls of a container with an electrically conducting fluid so that the resulting Lorentz forces will affect the flow throughout the domain or in desired regions only, so that desired thermal gradients could be maintained and desired solid/melt interface topology could be created and preserved during unsteady solidification.
Implicit numerical algorithms were developed and used in this research to integrate equations of classical magnet-hydro-dynamics and classical electro-hydro-dynamics. The algorithms utilized finite volume method and a hybrid optimizer with automatic switching among different optimization modules. Both algorithms were used to develop accurate computer codes for prediction and optimization of solidification from a melt under the influence of externally applied magnetic and electric fields. The objective was to find such distributions of intensities of wall-mounted magnets and electrodes that will create desired features of the flow-field or melt/solid interface topology. The computational results indicate significantly different flow-field patterns and thermal fields in the melt and the accrued solid in the cases of externally applied optimized magnetic and electric fields. This clearly suggests the possibility of developing smart manufacturing protocols for creating objects that will have functionally graded physical properties.

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133-144 pages

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