Three-Dimensional, Time-Dependent SpectralElement Simulations of a Thermocapillary LiquidBridge with Magnetic Stabilization

[摘要] The spectral element method is used to obtain 3D, time-dependent solutions for athermocapillary driven liquid bridge with magnetic stabilization, which arises from thefloat-zone crystal growth process. The methods and implementation of the general,in-house developed fluid flow and heat transfer spectral element solver are discussedand the code is benchmarked. This work compares three-dimensional, time-dependentresults to perturbations predicted by linear stability theory for the full-zone problemwith Prandtl number of 0.02. Critical points, mode numbers, and azimuthal velocityperturbations are matched for the instabilities. Additionally, the simulations extendthe study beyond the initial bifurcation point to find modal competition between twosteady modes for the zero magnetic field case. Applying an axial magnetic field dampsthe perturbations and delays instabilities, providing a quiescent interior region that isconducive to growing defect free, uniform composition crystals. Weak magnetic fieldsare shown to remove the modal competition that leads to undesirable, time-dependentflow with mode switching.

[发布机构] Rice University

[效力级别] engineering