直管式科氏质量流量计对脉动流响应的研究

弹性测量管的振动特性决定了科氏质量流量计的测量精度.以直管科氏质量流量计为例,初步分析研究了流体脉动对其测量管振动特性的影响.建立了被测流体脉动时测量管振动的数学模型;采用Galerkin法对模型进行了处理,将模型转化为受外激励和参数激励联合作用的有耦合多自由度振动问题;用多尺度法对其进行了分析,给出了脉动流作用下科氏质量流量计测量管振动的主要频率成分,揭示了脉动流作用的机理.所得到的大部分结论与有关文献的实验结果吻合.

Analysis on Response of Straight Tube Coriolis Mass-Flow Meter under Pulsating Flow

The measurement error of Coriolis mass flow meter is based on the vibration characteristics of the elastic tube of flow meter. In this paper, the influence of pulsating flow on performance of Coriolis mass flow meter is analyzed, with the straight tube Coriolis mass flow meter as the investigated object. The mathematical model of vibration of straight tube Coriolis mass flow meter under pulsating flow is established. By making use of Galerkin method, the model is converted into a coupled multi degree system under combined parametric and forcing excitation. Multiscale method is used to analyze qualitatively the discrete multi degree system, the main vibrational components of the tube under pulsating flow are given, and thus the mechanism of action of pulsating flow to Coriolis mass flow meter is shown clearly. Most of conclusions obtained here have been testified by experiments that were reported in the published papers. The conclusions are helpful to further investigation and application of Coriolis mass flow meter.