"Nonlinear Stability of Interfacial Fluids in Microchannels" Entwicklung von numerischen und asymptotischen Modellen zur Beschreibung des Stabilitätsverhaltens von Grenzflächenströmungen in Mikrokanälen unter dem Einfluss von elektrischen Feldern.

液膜流动存在于流体力学的许多应用中，包括冷却系统、涂层工艺、燃烧和生物应用。对这类系统的稳定性和非线性状态的基本分析是很有意义的，因为动力学可以提高诸如热量和传质速率之类的量。众所周知，电场可以用来控制重要的物理方面，如界面稳定性的性质和破裂事件中奇点的出现。虽然已经有很多关于微通道中界面流动的线性和非线性稳定性的研究，但关于电场对这些流动的影响的研究很少。最近，NJIT的实验表明，当电场作用于流体时，微通道界面流动中存在一种非线性破碎机制。使用有限的电极，由于电场产生不稳定，因此可以以开关的方式控制流量。到目前为止，还没有对整个问题进行详细的研究。为了加深对带电微流体界面流的非线性稳定性的理解，本研究对技术上具有重要意义的带电微流道流进行了系统的数值模拟。特别关注界面稳定性、行波形成和液滴事件。

Liquid film flows occur in many applications of fluid mechanics including cooling systems, coating processes, combustion, and biological applications. The fundamental analysis of the stability and nonlinear states of such systems is of interest since the dynamics can enhance quantities such as heat and mass transfer rates. It is well known that electric fields can be used to control important physical aspects such as the properties of interfacial stability and the onset of singularities during rupture events. Although there have been numerous studies of the linear and nonlinear stability of interfacial flows in micro channels, research on the effects of electric fields acting on these flows is very rare. Recently, experiments at the NJIT have shown a nonlinear breakup mechanism in microchannel interfacial flow when an electric field acts on the fluids. Using finite electrodes, the flow can be controlled in a switching manner since the field produces instability. Detailed studies of the full problem have not been carried out so far. To improve understanding of the nonlinear stability of electrified microfluidic interfacial flows that cannot be addressed by asymptotic approaches, a full numerical simulation of the technically important electrified Poiseuille microchannel flow in a systematic way is proposed in this research. Special attention is devoted to interfacial stability, traveling wave formation, and droplet events.