利用涡旋原理减小流体黏性对浮子流量传感器测量影响的研究

Application of eddy field in the design of floating element for decreasing the effect of viscosity

为了减小黏性流体对浮子流量传感器测量的影响,本文采用优化浮子结构的方法来设计黏性不敏感浮子传感器,运用计算流体力学(CFD)的方法对测量黏性介质的浮子流量传感器进行了数值仿真,在仿真分析的基础上,发现流体在边界层分离产生的涡旋流场可以减小黏性对浮子流量传感器测量的影响,研究分析了利用涡旋场减小流体黏性影响的机理与减黏浮子结构的特征;同时设计制造了利用涡旋效应实现减黏的浮子流量传感器,利用黏性物理实验对减黏浮子的减黏效果进行了验证,具有减黏效果的浮子流量传感器在1-495 mPa.s的黏性范围内,介质黏性所引起的测量误差可控制在2.9%以内。

The paper presents the method optimizing the structure of the floating-element flow sensor in design of rotameter for reducing the viscous effect of fluid on the measured results. The floating-element flow sensor of rotameter is numerically simulated by CFD method. Based on the analysis from simulation, it is found that the vortex field generated by the flow separation can weaken the viscous effect on the measured results. The mechanism of visbreaking by vortices and the structure of vis- breaking sensor have been investigated in details. Meanwhile, the new type of sensor has been created and manufactured according to the principle of visbreaking. The visbreaking effect of the sensor, examined with experiment, shows that the new type sensor provides significant visbreaking function, which makes the maximum error of measurements less than 2.9% in the fluid with viscosity from 1 to 495 mPa·s.