可用于微型开关研发的液态金属桥拉伸断裂过程仿真研究  

Simulation Analysis of Stretch Induced Breakup of a Liquid-Metal Bridge for the Development of Micro-Switches

作　　者：朱晓楠 杨飞[2] 张云轩 孙晋茹 荣命哲[2] Zhu Xiaonan;Yang Fei;Zhang Yunxuan;Sun Jinru;Rong Mingzhe(The 705 Research Institute China State Shipbuilding Corporation Limited,Xi’an 710077 China;School of Electrical Engineering Xi’an Jiaotong University,Xi’an 710049 China)

机构地区：[1]中国船舶集团有限公司第705研究所,西安710077 [2]西安交通大学电气工程学院,西安710049

出　　处：《电工技术学报》2024年第17期5508-5520,共13页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(52077172);陕西省三秦创新团队“先进直流电力装备关键技术及其产业化示范创新团队”资助项目。

摘　　要：构建流体仿真模型可以有效地分析液桥拉伸断裂过程中的流体动力学特性,为基于液态金属桥拉伸断裂过程的电弧开断性能调控提供指导。已有的液桥仿真模型基于动网格或其他网格变形方法,无法仿真液桥的大范围拉伸形变和几何断裂。为此,该文提出了一种不依赖网格形变的液桥拉伸断裂有限元仿真方法。该方法对液体设置极大黏度值,以不可流动液体区域对固体进行近似,同时通过极大黏度值界线的移动配合计算域内液体的流出来等效液桥的拉伸,实现了对液桥拉伸断裂过程的仿真。基于该仿真模型探究了液桥体积、拉伸速度等对液桥拉伸断裂过程的影响,获得了全拉伸速度范围内液桥拉伸断裂特性的转变规律。最终,结合实验结果分析了液桥拉伸断裂特性转变对于电弧燃烧模式的影响,给出了全拉伸速度范围内电弧燃烧模式转变相图,为液桥式开关的电弧开断性能调控提供了依据。该文研究内容对微型继电器、接触器等基于液桥断裂原理的微型开关研发具有指导意义。Traditional mechanical switches use a pair of solid-metal sheets as conductive contacts to achieve switch operations.Existence of conductive spots leads to a series of electrical contact stability problems such as the increase of contact resistance,electrodynamic repulsion force between closed contacts and the generation of switching arcs in current breaking,which seriously affect the service life of mechanical switches,especially microswitches like relays and miniature circuit breakers.Stretching a liquid-metal bridge to breakup could realize rapid arc breaking of low-voltage DC ampere-level currents,thereby eliminating the above electrical contact problems caused by solid conductive spots.Constructing a simulation model can effectively analyze the fluid dynamics of a liquid-metal bridge during the stretch induced breakup,providing guidance for the regulation of the liquid-metal bridge’s arc breaking performance.Most existed models for liquid bridge’s breakup simulation are based on moving mesh or other mesh deformation methods,which cannot simulate the wide range deformation or geometric rupture of a liquid bridge.To address the above issue,a finite element simulation method that doesn’t rely on grid deformation for liquid bridge’s breakup is proposed here.This method approximates solids by setting a maximum viscosity for liquids,and simulates the liquid bridge’s stretch process by moving the boundary of the maximum viscosity area cooperating with the liquid mass flowing out of the calculating domain.Fluid variations of the liquid bridge obtained from the model are in good agreement with experimental results,in terms of time scale and geometric shape.The model could be used to accurately track the boundary movement and profile development of a liquid bridge during the whole breakup process.Based on this model,fluid dynamics of a liquid bridge during stretch induced breakup could be accurately predicted.Based on the model,the effects of liquid metal volume and stretching speed on the breakup characteri

关 键 词：电弧和电接触 液态金属桥 机械开关 直流开断 有限元仿真 流体仿真 

分 类 号：TM501[电气工程—电器]