Three-Dimensional Gravity-Jitter Induced Melt Flow and Solidification in Magnetic Fields

A full three-dimensional transient numerical model is presented for gravity- ( g-) jitter induced melt e ow and solidie cationphenomenawithandwithoutexternallyappliedmagnetice eldsduringthemeltgrowthofSn-dopedBi singlecrystalsin microgravity.Themodel isdeveloped basedonaEulerian‐ Lagrangian e niteelementformulation, coupled with a mesh-deforming algorithm to track the solidie cation front. Extensive numerical simulations are carriedout,andthestudiedparametersincludesoluteconcentration-dependentmeltingtemperature,solidie cation interface morphology, magnetic e eld direction and magnitude, idealized microgravity condition, and synthesized and real g-jitter data conditions. Computed results show that g-jitter induced melt e ow is time dependent and exhibits a complex three-dimensional structure and that the e ow can have detrimental effects on solute concentration distribution. The g-jitter induced melt e ow and its deleterious effects on solidie cation can be suppressed by externally applied magnetic e elds. The three-dimensional numerical simulations suggest that a two-dimensional model is useful in providing some essential features of g-jitter induced e ow and solidie cation behavior with and without externally applied magnetic e elds and that a three-dimensional model is required to resolve fully the complex spatial e ow structure when all g-jitter components are operative during a realistic space e ight.

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