Convective heat transfer control using magnetic and electric fields

A practical approach to non-intrusive control of electrically conducting melt flow-fields and heat transfer could be achieved by using externally applied magnetic and electric fields. This approach can also be used to enhance the convective heat transfer. Computational methods are needed to give us better 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 could 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 magneto-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.