界面润湿性及固相体积分数对颗粒粗化动力学影响的相场法研究  

Phase field modeling of the influence of interfacial wettability and solid volume fraction on the kinetics of coarsening

作　　者：王陶[1] 李俊杰[1] 王锦程[1] 

机构地区：[1]西北工业大学,凝固技术国家重点实验室,西安710072

出　　处：《物理学报》2013年第10期324-332,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51101124;51071128);国家重点基础研究发展计划(批准号:2011CB610401);教育部博士点基金(批准号:20116102120018);凝固技术国家重点实验室基金(批准号:67-QP-2011)资助的课题~~

摘　　要：利用多相场模型模拟了液-固两相体系中固相颗粒的粗化过程,分析了界面润湿性及固相体积分数对粗化指数、粗化速率及颗粒尺寸分布的影响.结果表明,不同固相体积分数下粗化指数基本不变,但粗化速率常数及尺寸分布与固相体积分数及界面润湿性密切相关.在完全润湿条件下,随着固相体积分数的增加,粗化速率常数逐渐增大;而非完全润湿条件下,随着固相体积分数的增加,粗化速率常数增大速度变缓,且当润湿性较低、固相分数较大时,粗化速率常数还将随体积分数的增加而下降.此外,模拟结果表明各种润湿条件下颗粒的尺寸分布均随着固相分数增加而变宽,分布峰值降低,但非完全润湿条件下峰值下降变缓.模拟结果为理解不同实验观测结果之间的分歧提供了依据.Coarsening of solid particles in a solid-liquid two-phase system with high solid volume fraction is studied using the multiphasefield model.The influences of interfacial wettability and solid volume fraction on growth exponent,coarsening rate,and particle size distribution（PSD）are analyzed.It is found that the growth exponent is independent of the volume fraction,while the coarsening rate constant and the PSD are closely related to the interfacial wettability and the solid volume fraction.Under the completely wetting condition the coarsening rate constant increases with volume fraction increasing,but this variation is insignificant under the incompletely wetting condition.Moreover,when the wettability is low and volume fraction is high,the coarsening rate may also decrease with volume fraction increasing.The simulation results also show that with the increase of volume fraction,the peak frequency decreases and the PSD becomes broader,but the fall of the peak frequency under the incompletely wetting condition is slower than under the completely wetting condition.The simulation results provide an insight into the discrepancy between different experimental observations.

关 键 词：粗化 相转变 相场法 润湿性 

分 类 号：O359[理学—流体力学]