螺杆分配机头口模出口高度变化对流场的影响

The Influence of the Screw Die Outlet Height Changes on Flow Field

为了研究口模出口高度变化对螺杆分配机头内部流场和挤出均匀性的影响,参数化有限元分析技术贯穿于螺杆分配机头CAE仿真的全过程,采用VISUAL C++和APDL语言开发出专用有限元前处理程序和特殊加载宏,调用ANSYS对螺杆分配机头流道内部流场进行三维有限元模拟与分析。分析结果表明:口模出口高度变小将增加流道内的流动阻力,显著增大狭缝流道内各部分区域过渡截面中间层节点的压力值和口模出口的挤出速度值。当口模出口高度调节较大时,有必要重新调节阻尼块以提高速度分布的均匀性。

In order to study the influence of Screw Die outlet height changes on the flow channel and extrusion uniformity, Parametric FEA technology was used in the whole process of Screw Die CAE simulation, special finite element pre-pro- cessing programs and loaded macros were developed by APDL （ANSYS parametric design language） and VISUAL C＋ ＋ language, which could call ANSYS to simulate and analyze the three-dimensional finite element model of Screw Die flow channel. It is possible to conclude that reduce the height of the die outlet should increase the flow resistance, significantly increase pressure in the slit flow channel and extrusion velocity near the die outlet. When the die outlet height adjustment is large, it is necessary to re-adjust the damping block in order to increase the uniformity of velocity profile.