对“关于黏弹性流体库埃特流启动的注记”的评论 [Phys. Fluids 35, 113108 (2023)]
Comment on "Note on the start-up of Couette flow for viscoelastic fluids" [Phys. Fluids 35, 113108 (2023)]
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中文总结 AI 辅助
指出Balan论文初始条件与延迟时间不相容，实际求解为斜坡启动而非脉冲启动，其数值结果符合斜坡解，壁面应力异常为网格伪影，并提供开源代码验证。
中文摘要 AI 辅助
我证明了Balan [Phys. Fluids 35, 113108 (2023)] 施加的初始条件与非零延迟时间不相容，因此所求解的问题并非脉冲启动，而是（如我精确证明的）在延迟时间尺度λ2（一个材料参数，而非流变仪中的设置）上，平板以1 - e^{-t/λ2}形式斜坡启动。从该论文黏弹性图中数字化得到的数值落在斜坡平板解上，而非Tanner的启动解上。对共旋模型报告的大负壁面法向应力是由于初始数据中的相同错误导致的网格依赖伪影。一个开源代码仓库提供了带注释的笔记本，可重现本评论中的每个图形和数值。
英文摘要
I show that the initial conditions imposed by Balan [Phys. Fluids 35, 113108 (2023)] are incompatible with a nonzero retardation time, so that the problem solved is not impulsive start-up, but, as I prove exactly, the start-up of a plate ramped as $1 - \mathrm{e}^{-t/λ_2}$ on the retardation timescale $λ_2$ (a material parameter, not a setting in a rheometer). Values digitized from that paper's viscoelastic figures fall on the ramped-plate solution, not on Tanner's start-up solution. The large negative wall normal stress reported for the corotational model is a grid-dependent artifact due to the same error in the initial data. An open-source code repository provides annotated notebooks reproducing every figure and number in this Comment.
发表机构
- School of Mechanical Engineering, Purdue University（普渡大学机械工程学院）
机构由 AI 辅助整理，请以论文原文为准。
