标题： 电荷粘附射流在气流中的鞭打现象 显示英文标题

标题： Whipping of electrified visco-capillary jets in airflows

摘要： 带电的粘性毛细射流表现出不同的动态行为，例如锥形形成、断裂成液滴、鞭打和卷曲，这取决于所考虑的参数范围。 在之前的论文中，对电纺丝具有基础重要性的鞭打不稳定性是通过稳定性分析来研究的。 在这项工作中，我们提出了一个替代的模型框架，其中不稳定性可以作为渐近柯西杆描述的稳定稳态解直接计算出来。 为此，我们采用了一种由Ribe（Proc. Roy. Soc. Lond. A, 2004）提出的程序，该程序相对于一个以先验未知的鞭打频率旋转的参考系来描述射流动力学，而该频率本身也成为了解的一部分。 该杆模型允许拉伸、弯曲和扭转，考虑了惯性、粘性、表面张力、电场和空气阻力。 对于由此产生的常微分方程的参数边值问题，我们提出了一种延续-配点方法。 在五阶隐式龙格-库塔方案的基础上，我们开发的延续过程使得在高维参数空间中高效且稳健的仿真和导航成为可能。 尽管所采用的电场模型很简单，但数值结果令人信服，鞭打效应得到了很好的定性描述。 显示英文摘要

摘要： An electrified visco-capillary jet shows different dynamic behavior, such as cone forming, breakage into droplets, whipping and coiling, depending on the considered parameter regime. The whipping instability that is of fundamental importance for electrospinning has been approached by means of stability analysis in previous papers. In this work we alternatively propose a model framework in which the instability can be computed straightforwardly as the stable stationary solution of an asymptotic Cosserat rod description. For this purpose, we adopt a procedure by Ribe (Proc. Roy. Soc. Lond. A, 2004) describing the jet dynamics with respect to a frame rotating with the a priori unknown whipping frequency that itself becomes part of the solution. The rod model allows for stretching, bending and torsion, taking into account inertia, viscosity, surface tension, electric field and air drag. For the resulting parametric boundary value problem of ordinary differential equations we present a continuation-collocation method. On top of an implicit Runge-Kutta scheme of fifth order, our developed continuation procedure makes the efficient and robust simulation and navigation through a high-dimensional parameter space possible. Despite the simplicity of the employed electric force model the numerical results are convincing, the whipping effect is qualitatively well characterized.