摘要
借鉴传统流体Cross_Law宏观黏度模型,引入基于分子链段长度的尺寸修正因子,建立反映微尺度流动特性的微观黏度模型.通过对比厚度为70和80μm薄板注塑填充率的实验与数值仿真结果,验证所建模型的准确性,分析微观黏度对微流动的影响规律.结果表明,随流道特征尺寸减小,微观黏度值减小,但维持相同流动速度的注射压力增大,流体剪切速率增大,而流道中心流速基本不变,熔体黏度最大值位置逐渐偏离流道中心.
According to the traditional Cross_Law model, a new micro-scale viscosity model reflecting the micro flow characteristics was established by introducing the dimension correction factor based on the molecular chain length. The model was verified by comparing the simulation filling ratio with micro injection experimental filling ratio of the 80 μm and 70 μm thick sheets. The research of the influence of micro-scale viscosity on melt flow was carried out by analyzing the change of viscosity distribution, injection pressure and flow velocity. The results show that along with the decrease of feature size of injection mold, the micro-scale viscosity becomes smaller and the injection pressure has to increase to maintain the same flow velocity. In addition, the shear rate increases and the position of max melt viscosity gradually deviates from the flow center because of the micro channel.
出处
《深圳大学学报（理工版）》
EI
CAS
北大核心
2013年第6期629-635,共7页
Journal of Shenzhen University(Science and Engineering)
基金
国家自然科学基金资助项目(51175348)
深圳市科技计划资助项目(JCYJ20120917163755066)~~
关键词
精密制造
微观黏度模型
微注塑
填充率
分子链段长度
流动行为
precision manufacturing
micro-scale viscosity model
micro injection molding
filling ratio
molecularchain length
flow behavior
