SCI和EI收录∣中国化工学会会刊

›› 2011, Vol. 19 ›› Issue (1): 10-17.

• • 上一篇    下一篇

Numerical Simulation of Viscoelastic Extrudate Swell Through Elliptical Ring Die

许星明1,2, 赵国群2, 秦升学3, 王威1   

  1. 1. College of Mechanical and Electrical Engineering, Shandong University of Science and Technology, Tai’an 271019, China;
    2. Engineering Research Center for Mold&Die Technologies, Shandong University, Jinan 250061, China;
    3. College of Mechanical and Electrical Engineering, Shandong University of Science and Technology, Qingdao 266510, China
  • 收稿日期:2009-12-13 修回日期:2010-12-12 出版日期:2011-02-28 发布日期:2011-02-28
  • 通讯作者: ZHAO Guoqun, E-mail: zhaogq@sdu.edu.cn
  • 基金资助:
    Supported by the National Science Foundation for Distinguished Young Scholars of China(50425517);the Shandong Province Natural Science Foundation(Y2007F59)

Numerical Simulation of Viscoelastic Extrudate Swell Through Elliptical Ring Die

XU Xingming1,2, ZHAO Guoqun2, QIN Shengxue3, WANG Wei1   

  1. 1. College of Mechanical and Electrical Engineering, Shandong University of Science and Technology, Tai’an 271019, China;
    2. Engineering Research Center for Mold&Die Technologies, Shandong University, Jinan 250061, China;
    3. College of Mechanical and Electrical Engineering, Shandong University of Science and Technology, Qingdao 266510, China
  • Received:2009-12-13 Revised:2010-12-12 Online:2011-02-28 Published:2011-02-28
  • Supported by:
    Supported by the National Science Foundation for Distinguished Young Scholars of China(50425517);the Shandong Province Natural Science Foundation(Y2007F59)

摘要: The numerical simulation of extrudate swell is significant in extrusion processing.Precise prediction of extrudate swell is propitious to the control of melt flow and the quality of final products.A mathematical model of three-dimensional(3D)viscoelastic flow through elliptical ring die for polymer extrusion was investigated.The penalty function formulation of viscoelastic incompressible fluid was introduced to the finite element model to analyze 3D extrusion problem.The discrete elastic viscous split stress(DEVSS)and streamline-upwind PetrovGalerkin(SUPG)technology were used to obtain stable simulation results.Free surface was updated by updating the streamlines which needs less memory space.According to numerical simulation results,the effect of zero-shear viscosity and elongation parameter on extrudate swell was slight,but with the increase of volumetric flow rate and relax time the extrudate swell ratio increased markedly.Finally,the numerical simulation of extrudate swell flow for low-density polyethylene(LDPE)melts was investigated and the results agreed well with others’work.These conclusions provided quantitative basis for the forecasting extrudate swell ratio and the controlling of extrusion productivity shape.

关键词: viscoelastic fluid, extrudate swell, finite element method, polymer extrusion

Abstract: The numerical simulation of extrudate swell is significant in extrusion processing.Precise prediction of extrudate swell is propitious to the control of melt flow and the quality of final products.A mathematical model of three-dimensional(3D)viscoelastic flow through elliptical ring die for polymer extrusion was investigated.The penalty function formulation of viscoelastic incompressible fluid was introduced to the finite element model to analyze 3D extrusion problem.The discrete elastic viscous split stress(DEVSS)and streamline-upwind PetrovGalerkin(SUPG)technology were used to obtain stable simulation results.Free surface was updated by updating the streamlines which needs less memory space.According to numerical simulation results,the effect of zero-shear viscosity and elongation parameter on extrudate swell was slight,but with the increase of volumetric flow rate and relax time the extrudate swell ratio increased markedly.Finally,the numerical simulation of extrudate swell flow for low-density polyethylene(LDPE)melts was investigated and the results agreed well with others’work.These conclusions provided quantitative basis for the forecasting extrudate swell ratio and the controlling of extrusion productivity shape.

Key words: viscoelastic fluid, extrudate swell, finite element method, polymer extrusion