螺杆中销钉混合功能的计算机模拟

从理论上研究了销钉对流体的混合作用,分析了流体在销钉间的运动状态及变形情况.以及流体的绕流及剪切变形对混合的影响.用计算机对流体在销钉间的运动状态进行模拟,采用有限元法分别计算出当销钉的直径、间距、排布形式及螺杆的转动速度发生变化时,流场中流体的速度分布、压力分布及变形情况.在此基础上用加权平均总应变作为评定指标,对各种情况下的混合效果进行了对比分析.结果表明,在销钉的作用下,粘性流体既发生剪切变形,又发生拉伸变形,正是这两种变形情况的同时存在,强化了混合效果.螺杆的转速、销钉的直径、销钉间距离以及销钉的排列形式都对流体的混合状况有明显的作用.

The Computer Simulation to the Function of the Screw With a Pin Mixing Section

Theoretical study of the mixing of fluid due to pins is presented by analyzing the movement and distortion of the fluid around the pins. This paper used a computer to simulate the condition of fluid flow around the pins and calculated the velocity and pressure distribution in the flow field by The Finite Element Method when the diameter, space, shape, arranged manner of pins and rotation velocity of the screw changed. According to the calculated result, the weighted average total strain has been chosen as a mixing index to evaluate mixing effectiveness for each condition. The result shows that under the actions of pins viscous fluid produced both shearing and tensile distortion. It is for the existence of the two distortions the mixing is intensified. The diameter, space, shape, arranged manner of pins and rotation velocity of the screw all have obvious functions to the mixing.