微加速度开关中水银微液滴流动特性的研究

Research on Characteristics of Mercury Droplet Flow in Micro Acceleration Switch

为了解决传统微加速度开关接触磨损、信号跳变等问题,增强接触可靠性,采用液态金属取代传统微开关的固-固接触方式。基于液态金属的微加速度开关是通过液态金属水银液滴在加速度作用下实现开关动作,具有无可动部件、低接触电阻、寿命长、允许通过大电流等特点。利用FLUENT软件的VOF-CSF模型对水银微加速度开关进行了数值仿真分析,研究了接触角、水银体积和温度对水银在微加速度开关中流动特性的影响。为能真实反映水银流动特性,更采用FLUENT中的用户自定义程序UDF考虑了动态接触角的情况。仿真结果与理论结果表明接触角和水银微液滴体积对流动特性影响较大,温度对流动特性影响较小。

To solve the contact problems and enhance reliability, such as contact wear and signal bounce, solid-solid contact was replaced by liquid metal （LM） in a micro acceleration switch. A LM-based micro switch used LM droplet to achieve switching with no moving structures, low contact resistance, long life and a large current. Based on the VOF-CSF model of FLUENT, simulations of micro acceleration switch were performed and the effect of contact angle, droplet volume and temperature were discussed. UDF was employed to study the effect of dynamic contact angle to reflect the mercury droplet flow characteristics. The simulation results show that the influences of contact angle and droplet volume on flow characteristics are significant while the influence of temperature is small.