Abstract: The flow fields in four kinds of combined screws of the tri-screw extruders were analyzed by using finite element method. The velocity, pressure, maximum shear rate, maximum stretching rate and residence time distribution in four extruders were specially analyzed. The results showed the combined screws of the triscrew extruders could weaken the axial velocity to a certain extent and increased the residence time distribution. Those were beneficial to the full mixing of the material. Moreover, the effects of screw deformation on fluid-structure coupling were further analyzed by ANSYS workbench. By comparison, the design of combined screws four was more reasonable due to the high mixing performance and the small deformation of screws.

Key words: Tri-screw extruders, Combined screws, Flow field analysis, Fluid-structure interaction, Screw deformation

摘要： 采用有限元法对4种三螺杆挤出机组合螺杆流体进行流场分析,重点分析了速度场、压力场、最大剪切速率、最大拉伸速率、停留时间的分布情况。结果表明,组合螺杆在一定程度上能够削弱轴向速度,延长停留时间,有利于物料充分混合。在此基础上,采用ANSYS/workbench软件进一步分析了流固耦合作用对三螺杆挤出机组合螺杆变形的影响。分析结果表明,组合4混合性能较好,耦合场作用下螺杆变形相对较小,设计较为合理。

关键词: 三螺杆挤出机, 组合螺杆, 流场分析, 流固耦合, 螺杆变形