不同运动方式KDP单晶生长流动与物质输运数值分析

针对两种不同运动方式下的KDP单晶生长,进行了流动与物质输运模拟.分析和比较了不同运动方式下,晶面附近溶液流动及晶面过饱和度分布特征.研究了晶体尺寸对晶面过饱和度场的影响.结果表明:二维运动法中,晶面遭受的水动力学条件较为复杂,使得其过饱和度分布不如转晶法规则;二维运动法锥面过饱和度明显高于转晶法;单位周期内,转晶法晶面平均过饱和度存在较大波动,而二维运动法过饱和度随时间变化较小;总体上看,小尺寸晶体时,二维运动法晶面过饱和度梯度小于转晶法;大尺寸晶体时,二维运动法晶面过饱和度梯度大于转晶法.

Numerical Analysis of Flow and Mass Transfer for KDP Crystals Undergoing Two Different Motion Modes During Growth

Numerical simulations were conducted to model the flow and mass transfer involved in KDP crystals growth via two different motion modes.The features of solution flow around the crystal and the corresponding surface supersaturation distribution of two motion modes were compared and discussed.The effects of crystal size on surface supersaturation fields were analyzed.Simulated results indicated that when the 2D motion method (2D MM) was employed,the crystal surface experience complicate hydrodynamic conditions and its distribution of surface supersaturation was not as regular as that in rotating-crystal method.Additionally,its magnitude of pyramidal face was distinctly larger than that in rotating-crystal method.A considerable fluctuation occurred in surface supersaturation for a cycle in rotating-crystal method.By contrast,the variation of surface supersaturation in unit cycle was small as the crystal was grown by 2D MM.The gradient magnitude of surface supersaturation in 2D MM was less than that in rotating-crystal method for the smaller crystal,but it was larger than rotating-crystal method under the larger crystal.