高分子溶融体のダイ内流動シミュレーションに関する研究―近似手法の適用範囲の検討および三次元流動解析―
A Study on Simulation Method for Flow Analysis of Polymer Melts in Dies-Applicable Range of an Approximate Analysis Method and Three-dimensional Flow Analysis-
榊 一任・桑野善文・梶原稔尚・船津和守
Sakaki, Kazutaka / Kuwano, Yoshifumi / Kajiwara, Toshihisa / Funatsu, Kazumori
We have developed an approximate analysis method of polymer melt flow in dies, in which the velocity field was calculated by a pure-viscous non-Newtonian model and the stress field was obtained by substituting the velocity field in a viscoelastic model. The pure-viscous non-Newtonian model was modified so that the model could represent the strain-thickening effect of elongational viscosity. In order to examine the applicable range of this model to the flow analysis, we compared the velocity field for this model with that obtained from the Giesekus model with the same shear and elongational viscosities in a two dimensional contraction flow with various entry angles and flow rates. It was found that the deviation between the calculated results from both models was under 10 percent up to We=70. Furthermore, the deviation between the stress fields obtained from this method and the mixed method using the Giesekus model was under 30 percent.
A numerical simulation of three-dimensional flow in tapered contraction was also carried out by this approximate analysis method. The calculated results of stress distributions were compared with the experimental values measured by the flow birefringence technique. The stress distributions calculated were in good agreement with the experimental values. It was concluded that this approximate analysis method was applicable to practical flow analysis.
Key words: Polymer melts / Pure-viscous non-Newtonian model / Elongational viscosity / Approximate analysis method / Three-dimensional flow analysis