计算力学学报2019，Vol.36Issue(1)：83-89,7.DOI:10.7511/jslx20171111001
四螺杆扰动下粘性流体混沌动力学特性研究
Study on the chaotic dynamic properties of viscous fluid in four-screw extruders
摘要
Abstract
Under the periodic disturbance of the screws, the fluid motion of viscous polymer melt in the screw extruder has the characteristics of chaos.Different from the traditional Euler method, in this paper, the Lagrangian method was used to investigate the fluid transport properties in the four-screw extruders.Based on the finite time invariant manifold theory, the finite time Lyapunov exponent (FTLE) and Lagrangian coherent structures (LCS) of the four-screw extruders were calculated considering the different initial time.The LCS as a boundary separated three regions with different mixing characteristics in the screw extruders, in which the local regions with poor or good mixing performances were also identified.The accuracy of LCS patterns was verified by comparing with Poincaré section.The results show that the center region of the co-rotating four-screw extruder is surrounded by a closed LCS under the periodic disturbance of the co-rotating four screws.Therefore, the center region is a dead region of fluid transportation.By changing the rotating direction of the four screws, the closed LCS surrounding the center region is eliminated.This results in the increase of material exchange and mixing efficiency in the counter-rotating four-screw extruder.关键词
四螺杆挤出机/有限时间Lyapunov指数/拉格朗日拟序结构/Poincaré截面Key words
four-screw extruder/numerical simulation/Lagrangian coherent structures/Poincaré section分类
数理科学引用本文复制引用
朱向哲,佟莹,高鹤..四螺杆扰动下粘性流体混沌动力学特性研究[J].计算力学学报,2019,36(1):83-89,7.基金项目
国家自然科学基金 (51473073 （）
50903042) （）
辽宁省高校创新人才支持计划 (LR2016022) 资助项目. （LR2016022）
