Sedimentation of heavy crystal particles under microgravity conditions

Abstract

Crystals grown from specially prepared liquid solutions have important industrial applications such as in biochemical processes, refining etc. The efficiency of these crystals is usually a function of their size. Therefore, it is important to optimize the crystal size, and be able to control the defect location and concentration. For this reason, crystals have been grown in space in order to take advantage of the reduced gravity. However, due to the complexity of the microscopic chemical and macroscopic thermo-fluid phenomena, understanding of the growth of these crystals is still in its infancy. In this paper we present a high resolution finite element model describing the macroscopic dynamics of the fluid and the crystals under various microgravity conditions. The process is modelled by a set of coupled two-phase fluid dynamic equations and solved using a Finite Element segregated solution procedure. The numerical solutions were stabilized using concepts from flux corrected transport (FCT) scheme. Results are shown for the sedimentation rate and the complex velocity field induced by the motion of the heavy particles. © 1988 by the authors. Published by the American Institute of Aeronautics and Astronautics, Inc.