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力学与实践 ›› 2004, Vol. 26 ›› Issue (2): 0-0.doi: 10.6052/1000-0879-2003-027

• 应用研究 •    

用KBKZ型本构方程表征Boger流体黏弹性

黄树新 鲁传敏   

  1. 上海交通大学工程力学系 上海交通大学工程力学系 200030
  • 收稿日期:2003-01-21 修回日期:2003-07-01 出版日期:2004-04-10 发布日期:2004-04-10

DESCRIPTION OF VISCOELASTIC PROPERTIES FOR A BOGER FLUID BY USING KBKZ-TYPE CONSTITUTIVE EQUATIONS

  • Received:2003-01-21 Revised:2003-07-01 Online:2004-04-10 Published:2004-04-10

摘要: 用4个KBKZ积分型本构方程(Wagner模型、PSM模型、2e模型以及3r模型)描述了一种Boger 流体的黏弹性. 采用最小二乘法拟合$G'$ 和$G''$获得材料的松弛时间谱,采用非线性规划方法拟合$N_{1}$得到各模型的衰减函数参 数. 结果表明,4个模型都可以准确地表征该Boger流体的流变特性. 由于Wagner模型、PSM 模型较简单,选择这两个模型表征Boger流体的黏弹性是合适的.

关键词: Boger流体,黏弹性,KBKZ积分型本构方程

Abstract: Four KBKZ integral-type constitutive equations, including Wagner model, PSM model, 2e model and 3r model proposed by the authors, were used in the paper to describe the viscoelastic characteristics of a Boger fluid. The least square approximation was adopted to fit $G'$ and $G''$ to obtain the relaxation spectrum of the fluid, and the nonlinear programming method was employed to fit $N_{1}$ to obtain the parameter values in the damping function of the four models. The results show that the four models can characterize the rheological properties of the Boger fluid precisely. Either Wagner model or PSM model is a good choice for characterizing the viscoelastic properties of Boger fluid, due to its simplicity.

Key words: Boger fluid, viscoelastic properties, integral-type KBKZ