论文标题
边缘断裂和剪切带中的相互作用
Interplay of edge fracture and shear banding in complex fluids
论文作者
论文摘要
从理论上讲，我们通过在两个组成型模型中进行详细的仿真研究：Johnson-Segalman模型和Giesekus模型，从理论上探索剪切带和边缘断裂之间的相互作用。我们考虑分别的参数状态，其中基本构曲线是单调的和非单调的，因此散装流（在没有任何边缘效应的情况下）是同质和剪切带的。边缘干扰水平和散装（或准式）剪切条带的相位图作为流体空气界面的表面张力的函数，该界面符合流动池壁的润湿角以及施加的剪切速率。特别是，我们更详细地探讨了Hemingway等人最近宣布的基本结果。 （2018年）：边缘断裂的前体可以诱导准卵形剪切带。我们还评估了分析预测，即剪切带可能会诱导边缘断裂，Skorski和Olmsted（2011）。尽管对非凡的早期见解的研究，但该研究对“基本状态”的性质做出了一些有力的假设，我们使用直接数值模拟检查了该研究。剪切带可能会导致边缘断裂的基本预测仍然有效，但具有定性修改的相边界。
We explore theoretically the interplay between shear banding and edge fracture in complex fluids, by performing a detailed simulation study within two constitutive models: the Johnson-Segalman model and the Giesekus model. We consider separately parameter regimes in which the underlying constitutive curve is monotonic and non-monotonic, such that the bulk flow (in the absence of any edge effects) is respectively homogeneous and shear banded. Phase diagrams of the levels of edge disturbance and of bulk (or quasi-bulk) shear banding are mapped as a function of the surface tension of the fluid-air interface, the wetting angle where this interface meets the walls of the flow cell, and the imposed shear rate. In particular, we explore in more detail the basic result recently announced in Hemingway et al. (2018): that precursors to edge fracture can induce quasi-bulk shear banding. We also appraise analytical predictions that shear banding can induce edge fracture, Skorski and Olmsted (2011). Although a study of remarkable early insight, that study made some strong assumptions about the nature of the "base state", which we examine using direct numerical simulation. The basic prediction that shear banding can cause edge fracture remains valid, but with qualitatively modified phase boundaries.
