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

Evan B Baker; Jannatun Nawer; Xiao Xiao; Douglas M Matson

doi:10.1038/s41526-020-0099-7

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

NPJ Microgravity. 2020 Mar 16:6:9. doi: 10.1038/s41526-020-0099-7. eCollection 2020.

Authors

Evan B Baker¹, Jannatun Nawer¹, Xiao Xiao², Douglas M Matson¹

Affiliations

¹ 1Department of Mechanical Engineering, Tufts University, Medford, MA 02155 USA.
² 2Institut für Materialphysik im Weltraum, German Aerospace Center (DLR), Linder Höhe, D-51147 Köln, Germany.

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_39.5Zr_39.5Ni₂₁ 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.

Keywords: Aerospace engineering; Techniques and instrumentation.