微量摩阻天平旋转加载校准装置研制

Fabrication of rotary loading calibration device for skin friction micro-balance

为实现对微量摩阻天平/MEMS摩阻传感器进行静态校准研究,并且需要能够模拟高超声速风洞试验环境压力,建立微量摩阻天平旋转加载校准装置,对该校准装置的总体方案、旋转加载台体系统、真空系统和测控系统等进行研究。首先,提出基于离心力等效原理和真空箱体内单轴旋转加载方法的校准装置研制方案,开展旋转加载校准原理和校准装置总体方案研究。然后,分别对单轴旋转加载台体系统、模拟不同风洞试验环境压力的真空系统、旋转加载台体和真空箱体的磁流体动态密封以及专用的测控系统等方案进行详细设计。最后,完成校准装置研制,对该校准装置进行技术指标检测,并对研制的MEMS摩阻传感器样机开展校准应用。结果表明:微量摩阻旋转加载校准装置的速率范围在0.01～3 600°/s连续可调,速率精度优于0.01°/s,真空度20～5 000 Pa精密可测可控;静校的MEMS摩阻传感器样机输出稳定、回零好,测量范围均为0～100 Pa,分辨率为0.1 Pa,重复性精度和线性度优于1%。该校准装置速率精度高、稳定性好,校准过程中真空箱体的真空度可在30 min内达到20 Pa并得到很好保持,满足微量摩阻天平/MEMS摩阻传感器静态校准需求。

In order to realize static calibration for skin friction micro-balances or MEMS skin friction sensor and simulate different environmental pressures in hypersonic wind tunnel running,a rotary loading calibration device for micro skin friction measurement is established,and its general scheme,rotary loading platform system,vacuum system,and measuring and control system are investigated.First,fabrication scheme for calibration device basing on centrifugal force equivalent principle and rotary loading method in vacuum chamber is presented,and rotary loading calibration method and calibration device general scheme are researched.Then,the implementation of single-spindle rotary loading platform system,vacuum system,and measuring and control system are designed in details.On these bases,calibration device is developed,its indexes are detected,and the device is applied to calibrate MEMS skin friction sensor prototypes self-developed.Results indicate that rotary loading calibration device owns rate range in 0.01-3 600°/s area,rate accuracy better than 0.01°/s,and the vacuum that can be precisely measured and controlled in 20-5 000 Pa area;sensor prototypes calibrated own better stability and return-zero,skin friction measuring ranges are in 0-100 Pa area,their resolutions are 0.1 Pa,their repeatability accuracy and linearity are better than 1%.Calibration device developed owns higher rate accuracy and better stability,its vacuum can quickly achieve 20 Pa in 30 minutes and keep good condition;thus,it can satisfy the requirements of micro skin friction static calibration.