科氏质量流量计非线性振动特性研究(英文)

Nonlinear Vibration Characteristics of Coriolis Mass Flowmeter

科氏质量流量计(Coriolis mass flowmeter,CMF)当测量管振动幅度较小时,一般被认为是线性系统,但CMF输出信号频谱中具有倍频成分。结合CMF传感器的数学模型,在适当简化测量管边界条件的情况下,建立了考虑非线性因素和外部激励的直管型CMF测量管运动方程,并运用Galerkin方法对运动方程进行离散处理,由离散后的结果可以看出,系统含有多组非线性影响因素成分。针对测量管的闭环谐振和标准正弦信号受迫振动,分别采用激光测振仪对其振动状态进行测量,测量结果均含有非线性因素成分,证实了非线性分析的准确性;针对测量管的不同振动幅度进行了测量精度实验,验证了测量管振动幅度越大非线性影响越严重。理论分析结果和实验结果对CMF性能的进一步提高具有指导意义。

Coriolis mass flowmeter (CMF) is generally regarded as a linear system when the vibration amplitude of the measuring tube is relatively small, but the spectrum of its output signals still show existence of some multiple frequency components. Taking into consideration the nonlinear factors and external excitation, the motion equations of the CMF straight measuring tube are estab- lished by properly simplifying the boundary conditions of the measuring tube and integrating the mathematical model of the CMF sen...