FENE dumbbellモデルを用いた希薄高分子溶液の伸長流動特性のブラウン運動学シミュレーション: FENEパラメータおよび緩和時間の分布の影響

概要

論文の詳細を見る
Brownian dynamics (BD) simulations of the steady and transient rheological behaviors of FENE dumbbell model for dilute polymer solutions in uniaxial extensional flow are reported. The simulations include examination of the effects of distributions of maximum allowable extension (FENE parameter b) and of relaxation time parameter α. Stretch-thickening and strain-hardening behaviors, which can be often observed in polymer solutions, are confirmed in the simulations either with or without the distribution of b or α. However, overshoot phenomenon in a start-up extensional flow can never be observed unlike the situation in a start-up shear flow. Curves of transient extensional viscosity vs. strain clearly show that the extensional viscosity is independent of the stretch rate in the regime of αλ0ε>1~2 where polymer solutions exhibit significant strain-hardening. Furthermore, it is found that the distribution of b has little influence on extensional flow properties while the distribution of α can affect both the steady and transient extensional flow properties under the distribution condition used in the simulations. BD simulation can precisely predict the extensional viscosity even in the low stretch rate region.
日本レオロジー学会の論文
1999-06-15