MHD surrogate model for convection in electromagnetically levitated molten metal droplets processed using the ISS-EML facility

Abstract

Electromagnetic levitation experiments in space are an essential tool for thermophysical property measurement and solidification studies. In light of the need for material properties as inputs to industrial process modeling, investigators need new tools for efficient experiment planning. MHD surrogate modeling is a parametric method for prediction of flow conditions during processing using the ISS-EML facility. Flow conditions in model Au, Zr, and Ti 39.5 Zr 39.5 Ni 21 samples are predicted using the surrogate model. For Au, flow is shown be turbulent in nearly all experimental conditions, making property measurement difficult. For Zr, the flow is turbulent with the heater on and laminar with the heater off, allowing for property measurement during free-cooling experiments only. For TiZrNi, the flow is laminar under all experimental conditions, indicating that TiZrNi is an excellent candidate for EML experiments. This surrogate modeling approach can be easily applied to other materials of interest, enabling investigators to choose materials that will perform well in levitation and to tailor experiment parameters to achieve desirable flow conditions. npj Microgravity (2020) 6:9 ; https://doi.

Uncertainty analysis and performance evaluation of thermophysical property measurement of liquid Au in microgravity

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Thermodynamic assessment of evaporation during molten steel testing onboard the International Space Station

“…This powerful containerless technique simultaneously allows researchers to levitate and thermally condition molten metal droplets providing the advantage of processing samples without adverse impacts related to sedimentation, chemical reactions, or heterogeneous nucleation on crucible walls. The extended period of microgravity environment also enables the opportunity to conduct long duration experiments in the undercooled regime under a wide range of controlled flow conditions 17,18,19 . Fig.…”

Electromagnetic levitation containerless processing of metallic materials in microgravity: rapid solidification

“…As shown in Fig. 3a , magnetohydrodynamic modeling is used to evaluate stirring and melt shear as a function of experimental conditions and control convection to desired levels 84 – 87 . Differential evaporation from complex industrial alloys can also be monitored over the test duration to set experimental conditions to minimize the potential for unwanted compositional shifts for volatile components in the melt 88 .…”