悬浮式磁流体惯性传感黏阻与量程可控机理

Analysis of the viscous damping controllable principle of the suspend inertial sensors based on magnetic fluid

实现悬浮式磁流体惯性传感的量程控制关键在于分析基于经典黏性流体力学理论的动态黏度特性和流固系统运动特性.在质量块作简谐运动下,建立惯性传感结构中间隙的流动模型并对理论方程进行求解.在不同动力黏度下,对作简谐运动的传感运动块进行流阻力进行数值计算,结果表明:质量块所受黏阻力主要是两侧压力差,压力差随时间呈现简谐特性,幅值与磁流体动力黏度有较好的线性关系;在选定实验参数后研究结果为压差相位超前22°～40°,剪切应力超前在15°以内,且随着动力黏度增大而减少,当运动黏度达到75pma.s时,相位超前量变化趋缓.

In order to realize the expanded measurement range of the suspend inertial sensors based on magnetic fluid, it is the key to analysis the characteristic of dynamic viscosity and the movement of the fluid-structure interaction based on the classical theory of viscous fluid. In the situation of the mass body with simple harmonic motion, the mathematic model of the clearance flow in the sensors is established and the theory equation is analyzed. For the magnetic fluid with different viscosity, numeric analysis researches are done on the viscous damp of the mass body with simple harmonic motion. Numerical calculation indicates that the main part of the viscous damp which mass body suffers is the difference of the pressure in the two side of the mass body. The difference presents the harmonic character and its amplitude have the linearity relationship whit the viscosity of the magnetic fluid. When the parameters of the experiment are confirmed, the result indicates the phase of the difference of the pressure advances 22° -40°, and the phase advance of the cut stress is less than 15°. As the viscosity of the magnetic fluid increases, the phase advance decreases. Specially, when viscosity of the magnetic fluid is over 75 pma · s, the change of the phase advance is very small.