题目：Stability analysis and nonlinear dynamics for liquid thread in presence of surfactant: the effect of surface viscosity and electric field

主讲人：贺冬冬 教授

时间：2026年9月22日（星期二）15：00

地点：#腾讯会议：922-677-7312 

主办单位：国家天元数学西北中心、理学院

主讲人简介：

贺冬冬，香港中文大学（深圳）长聘副教授，校长青年学者，他于2012年取得加拿大约克大学应用数学方向博士学位。从2012年到2013年，他在香港城市大学数学系从事博士后研究。从2013年到2017年，他在同济大学任职助理教授和副教授。贺冬冬于2017年11月加入香港中文大学（深圳）。他的研究兴趣包括：流体力学、计算流体力学、应用渐近分析、偏微分方程数值解等。他已经在Journal of Fluid Mechanics、Journal of Computational Physics、Computer Methods in Applied Mechanics and Engineering、Journal of Scientific Computing、Journal of Non-Newtonian Fluid Mechanics、Communications in Nonlinear Science and Numerical Simulation、Physical Review E等期刊上发表论文五十余篇，其中在Journal of Fluid Mechanics上发表论文八篇。同时他主持国家省市项目多项。

摘要：

In this talk, I will present two recent work on stability analysis and numerical simulation for surfactant-covered liquid threads. Firstly, the linear and nonlinear stability analysis a surfactant-laden nonNewtonian viscoelastic Oldroyd-B/FENE-P thread will be presented, where the marangoni effect and surface rheology property induced by the surfactant are incorporated into the model. A set of longwave equations are obtained by using slender body approximation. Linear stability based on normal analysis was carried out, results show that the surfactant can decrease the unstable growth rate but cannot completely stabilize the system. Furthermore, for nonlinear studies, these longwave equations are solved by using finite difference methods. Results show surfactant can affect the dynamics of the threads greatly, surface viscosity of the surfactant can eliminate the satellite droplets, which has great potential in inkjet printing related applications. The fact that the surfactant can reduce the sizes of satellite droplets for the viscoelastic liquid jet is also preliminary verified by experiments. Secondly, nonlinear dynamics of an ionic surfactant-laden thread in a radial electric field is also studied by using one-dimensional long-wave model, where the interaction of surfactant and electric field is investigated. Results show that both the electric field and surfactants mitigate the breakup of the liquid thread and the formation of satellite droplets. When the applied potential is high, the electric stress has two main effects: the external electric field exerts a normal pressure on the liquid thread surface, suppressing satellite droplet formation, while the internal electric field inhibits liquid drainage.