微机械开放式射流陀螺的敏感原理和数值仿真

Research on Sensitive Mechanism and Numerical Simulation of Open Fluidic Gyroscope Based on MEMS

提出了一种基于开放式气流通道的微机械射流陀螺的设计、敏感原理和数值仿真。敏感元件内部气流的运动采用基于流固耦合的三维瞬态数值分析计算,计算和测试结果表明:(1)气流在压电泵的驱动下,由开放式气流通道的两个入口进入并汇聚,由喷口喷出并在射流敏感室形成射流敏感体,在入口和出口之间形成定向流动。(2)射流敏感体在哥氏力的作用下发生偏转,与作为电桥臂的热线发生热量交换,导致电桥输出与输入角速度成正比的不平衡电压。(3)陀螺灵敏度为SFZ=2.0μV/°/s,非线性度优于0.5%。

The design,sensitive mechanism and numerical simulation of an fluidic gyroscope based on MEMS with an open airflow channel are reported. The 3 D transient numerical analysis based on the fluid-structure interaction was used to calculate the movement of airflow in the sensitive element. Calculations and results indicated that：（1）With the drive of piezoelectric pump,the airflow flows into the open airflow channel through two inlets and then gather together. Then,the airflow flows through the nozzle and forms the sensitive jet flow in the fluidic sensing cavity,thus there is a directional flow between inlets and outlet.（2） Sensitive jet flow deflects because of the Coriolis Force and exchanges heat with the hotwires which forms the Wheatstone bridge. Therefore,Wheatstone bridge outputs an unbalanced voltage proportional to the applied angular velocity.（3）The sensitivity of mentioned gyroscope is SFZ= 2.0 μV/°/s,and simultaneously,the nonlinearity is better than 0.5%.