分割型有限要素法による粘弾性流体のダイスウェル流動解析
A Decoupled Finite Element Analysis of Die-swell Flow of Viscoelastic Fluids
岩田修一・新垣 勉・森 秀樹・秦 裕作・石川敏志・岩渕欽也
Iwata, Shuichi / Aragaki, Tsutomu / Mori, Hideki / Shin, Yusaku / Ishikawa, Satoshi / Iwabuchi, Kinya
A new decoupled finite element method has been applied to solving the extrudate flow of viscoelastic (single mode Giesekus) fluids, where non-consistent streamline upwinding and a 2x2 subelement were adopted for the constitutive equation. The elements were chosen to be 9-node quadrilaterals with biquadratic and bilinear interpolation functions for velocity components and pressures, respectively, while bilinear in each subelement for stress components. Additional subjects we examined in this study were : (1) substituting method of stress in momentum equation and (2) consistent interpolation of variables between constitutive and momentum equations. It turned out that the convergence behavior is greatly affected by a change in each treatment of the above subjects ; and a recommended scheme has been identified for improving the convergence behavior of decoupled method, which is able to predict the flow of viscoelastic fluids up to a Weissenberg number of 63.
Key words: Viscoelastic fluids / Giesekus model / Die-swell / Finite element / Decoupled method