磁性液体传感器一阶悬浮力的理论计算和仿真分析

一阶悬浮力是磁性液体传感器的设计关键。利用任意多物理场直接耦合分析软件COMSOL multiphysics仿真分析了磁性液体一阶悬浮力,一阶悬浮力在最大偏心距纵坐标为-2.5mm,横坐标在-20~25mm的范围内呈周期分布,其平均值为38.43N。同时对没考虑磁场和流场耦合情况下的一阶悬浮力进行了理论计算,仿真和理论计算均表明一阶悬浮力与偏心距离间存在非线性关系,一阶悬浮力的理论计算结果大于仿真分析结果,偏心距越大,理论计算与仿真分析的结果相差越大。磁性液体传感器的设计应该考虑磁场和流场的耦合作用。

Theoretical calculation and simulation analysis of the first order levitation force in ferrofluid sensor

The first order levitation force is the key factor in designing ferrofluid sensor. The first order levitation force is simulated by COMSOL multiphysics soft in this paper. The result shows that the first order levitation force exhibit periodic distribution in horizontal coordinate from -20mm to 25mm at maximum eccentricity, vertical coordinates -2.5mm, with average value of 38.43N of the first order levitation force. Meanwhile, the first order levitation force was theoretically calculated without considering the coupling between magnetic field and flow field, and nonlinear relationship between the first order levitation force and eccentric distance is confirmed by both simulation and theoretical calculation. The theoretical calculation result is higher than simulated analysis, and more eccentric distance results in larger diference. The coupling of magnetic field and flow field should be considered in design of ferrofluid sensor.