磁流体角速度传感器的固液接触电阻特性研究

针对基于磁流体动力学(MHD)的角速度传感器中源级输出电阻波动的抑制问题，主要分析了MHD角速度传感器金属电极与镓合金的接触电阻特性，以及随着应力改变和接触面粗糙度的变化规律。通过理论推导建立了传感器中固-液接触电阻的理论模型，并据此使用COMSOL仿真了不同接触应力下接触电阻的变化情况；使用接触角测量仪分析了电极粗糙度对接触电阻的影响，电极材料为铝或铁时，粗糙度由1.6增加到3.2时，接触角增加4°~10°。仿真表明，MHD角速度传感器的接触电阻随着接触应力的增加而减小，在1kPa应力变化范围内，固-液接触电阻急剧变化。接触角测试表明，随着粗糙度的增加，接触角增加，浸润性变差。

Research on Solid Liquid Contact Resistance Characteristics of Magnetohydrodynamic Angular Velocity Sensor

This paper mainly analyzes the contact resistance characteristics between metal electrode and gallium alloy with the change of stress and contact surface roughness, regarding the problems of suppression of the output resistance fluctuation in magnetohydrodynamic (MHD) angular velocity sensor. The theory of solid-liquid contact resistance in the MHD sensor is established and then COMSOL is used to simulate the change of contact resistance under different contact stresses. The influence of electrode roughness on contact resistance is analyzed using a contact angle measuring instrument. When the roughness increases from 1.6 to 3.2, the contact angle generally increases by 4°~10°. The simulation shows that the contact resistance of the MHD angular velocity sensor decreases with the increase of the contact stress. The solid-liquid contact resistance changes sharply in the range of 1kPa stress. The contact angle test shows that the contact angle increases and the wettability gets worse as the roughness increases.