【摘要】 针对传统微机械开关存在信号跳变、触点易磨损等缺点,设计了一种基于MEMS技术的水银微流体惯性开关。为了更准确地反映微通道中水银液滴在惯性力作用下的动态响应历程,基于Bracke、Jiang和Seebergh动态接触角模型编写用户自定义函数(UDF),并根据VOF-CSF多相流数值计算方法,采用FLUENT软件讨论了动态接触角对开关阈值特性和响应时间的影响,模拟了水银液滴在微通道中连续变形的动态过程。仿真结果表明,分别采用Bracke、Jiang和Seebergh模型所得阈值加速度之间的偏差较小,另外与设置静态接触角相比,三种不同模型使得阈值加速度分别增大了4.3%、3.2%和5.4%。更多还原

【Abstract】 A mercury micro-fluidic inertial switch based on MEMS was designed to solve disadvantages of the traditional micro-mechanical switch,such as signal bounce and contact wear. In order to accurately reflect dynamic response process of the mercury droplet in micro-channel under the effect of acceleration,the respective user defined function( UDF) was programmed based on Bracke,Jiang and Seebergh dynamic contact angle model. According to the numerical computation method for multiphase flow of VOF-CSF,the effect of dynamic contact angle on threshold characteristics and response time was discussed using FLUENT,and the dynamic continuous deformation process of the mercury droplet in micro-channel was simulated as well. The simulation results indicate that the deviation among the three threshold acceleration respectively obtained by utilizing Bracke,Jiang and Seebergh dynamic contact angle model is very small. In addition,the three dynamic contact angle models result in the increase of threshold acceleration by 4. 3%,3. 2% and 5. 4% as compared with setting static contact angle.更多还原