Convection Enhancement in Melting by Electromagnetic Fields in a Low-Gravity Environment: Side Wall Heating

Abstract

In this article the application of electromagnetic fields, both oscillating and static, are utilized to enhance the heat transfer (melting) of an electrically conducting phase-change material (gallium) under a low-gravity environment. Both transverse electric and oscillating or static magnetic fields are used to generate an oscillating Lorentz force to enhance convective mechanisms loss when the level of gravity decreases. The problem is formulated in one domain by employing an enthalpy-based transformation of the energy equation, which allows for one set of governing equations to be solved. The governing equations are then discretized using a control-volume-based finite-difference scheme. The results show that the application of either static or oscillating electromagnetic fields can be used to enhance the rate of melting of the phase-change material over the melt rate seen under true low gravity alone. In addition, it is determined that a static electromagnetic field can be used to enhance the melting rate more than with application of an oscillating electromagnetic field. Finally, the strongly three-dimensional and unique flow fields created by the application of either static or oscillating electromagnetic fields are documented.

Financial support for this work was provided by NASA Microgravity and a Raytheon Company “Advanced Study Scholarship.”