聚合物挤出成型过程狭缝组合流道出口流动平衡系数解析解  

Analytical Solution of Flow Balance Coefficient at the Outlet of Slit-combined Channel in Polymer Extrusion Process

作　　者：张广冬[1,2] 黄翔 ZHANG Guangdong;HUANG Xiang(School of Mechanical Engineering,Yancheng Institute of Technology,Yancheng 224051;College of Mechanical and Electrical Engineering,Nanjing University of Aeronautics&Astronautics,Nanjing 210016)

机构地区：[1]盐城工学院机械工程学院,盐城224051 [2]南京航空航天大学机电学院,南京210016

出　　处：《机械工程学报》2024年第12期259-267,共9页Journal of Mechanical Engineering

基　　金：江苏省六大人才高峰(RJFW-051);江苏省产学研合作(BY2020356)资助项目。

摘　　要：对于薄壁类塑料异型材挤出制品,其挤出模具成型段流道为狭缝组合流道。在挤出成型过程中,模具出口处的流动平衡状态直接影响着挤出制品的成型质量。狭缝组合流道出口处流动平衡系数通常依赖于数值模拟求解,技术门槛高,求解难度大,应用范围受限。针对上述问题,提出狭缝组合流道出口流动平衡系数的解析模型。首先,对流动平衡系数理论公式进行完全平方公式展开,得到流动平衡系数的速度相关项和无关项。然后,假定幂律流体在狭缝流道中充分发展流动,通过理论推导,得到狭缝流道出口处流动平衡系数的解析式。接着,基于狭缝组合流道的区域划分,根据不同狭缝流道子区域的速度比公式,建立狭缝组合流道出口流动平衡系数的理论模型。最后,针对典型的狭缝组合流道,采用数值模拟方法对流动平衡系数的解析值进行验证。结果表明,在各个子区域的宽高比大于10时,流动平衡系数的解析解和数值解的误差小于5%,满足实际应用需要。For thin-walled plastic profile extrusion products,the channel of the extrusion die forming section is a slit-combined channel.In the extrusion process,the flow balance at the die outlet directly affects the forming quality of extruded products.The flow balance coefficient at the outlet of the slit-combined channel usually depends on numerical simulation,which has high technical threshold,great difficulty in solving,and limited scope of application.In view of the above problems,an analytical model of the flow balance coefficient at the outlet of the slit-combined channel is proposed.Firstly,the theoretical formula of the flow balance coefficient is expanded by the complete square formula,and the velocity dependent and independent term of the flow balance coefficient are obtained.Then,assuming that the power-law fluid is fully developed in the slit channel,the analytical formula of the flow balance coefficient at the outlet of the slit channel is obtained through theoretical derivation.Then,based on the region division of the combined-slit channel and the velocity ratio formula of different sub regions,the theoretical model of the flow balance coefficient at the outlet of the slit-combined channel is established.Finally,the analytical value of the flow balance coefficient is verified by numerical simulation for a typical slit-combined channel.The results show that when the width-height-ratio of each sub region is greater than 10,the error of the analytical solution and numerical solution of the flow balance coefficient is less than 5%,which meets the needs of practical application.

关 键 词：挤出模具 流动平衡 狭缝组合流道 解析解 数值解 

分 类 号：TQ320[化学工程—合成树脂塑料工业]