U型振动管流体密度计的设计与实现

Fluid densimeter design and implimentation based on U-type tabe vibration modet

从力学角度对欧拉-伯努利梁的简谐振动进行分析,推导出梁的横向振动方程;在考虑边界条件的情况下推导出两端固定梁的频率方程和主振型函数;建立主振型频率与相应密度的关系解析式,求解得到目标流体密度.以此为基础,提出了一种基于振荡管的新型流体密度测量方法(系统).实验表明,相对于目前外业常用流体密度计,该流体密度计具有误差小于0.2%的高测量精度,且具有较好的抗恶劣环境的性能.

Harmonic oscillation of Bernoulli-Euler beam was analyzed in sense of mechanics to deduce its horizontal vibration function. The frequency function was developed with the principle vibrating function when its 2 terminals were fixed and the boundary condition was concerned. The target fluid density was ultimately solved from the density function of principle vibrating frequency. By means of the method mentioned above, a novel fluid densimeter was designed. The experiments showed that, compared with the currently applied outdoor devices, it had a higher measuring accuracy with the lower 0.2% relative error, as well it had well performance of bad-environment resistance.