双管型科氏质量流量传感器非线性影响抑制研究

Research on non-linear suppression of dual-tube Coriolis mass flowmeter

双管型科氏质量流量传感器输出信号中存在以倍频信号为主的非线性现象,已从数值分析角度进行溯源,本文借助ANSYS有限元分析软件构建全参数化模型,通过仿真实验进一步验证数值模型的可靠性;并通过分析耦合系统中测量管质量、定距板厚度、激励力大小对非线性振动的影响,证明测量管刚度和约束刚度对非线性的抑制有重要影响;进而采用附加质量法改善耦合系统局部刚度来抑制非线性倍频现象,结果显示改善局部刚度可以有效抑制和消除非线性现象;并且开展非线性抑制实验,结果符合仿真分析,验证了理论研究的正确性。为进一步细化非线性抑制方案、开展非线性抑制实验提供了理论支撑和技术指导,并可结合具体测量环境和测量需求,针对性的抑制或消除非线性现象,作为下一步CMF优化设计依据。

There is the nonlinear phenomenon in the output signal of double-tube Coriolis mass flowmeter,which is mainly the frequency doubling signal.The source has been traced from the perspective of numerical analysis.In this article,the full parametric model built by ANSYS finite element analysis software is used to further evaluate the reliability of the numerical model through simulation experiments.By analyzing the influence of the excitation force on the nonlinear vibration of the measuring tube mass and the thickness of the measuring tube spacing plate,it proves that the measuring tube stiffness and the constraint stiffness have important effects on suppressing the nonlinear vibration.Then,the additional mass method is used to improve the local stiffness of the coupling system to suppress the nonlinear frequency doubling phenomenon.Results show that the improved local stiffness can effectively suppress and eliminate the nonlinear phenomenon.The nonlinear suppression experiments are carried out,and the results accord with the simulation analysis,which verifies the correctness of the theoretical research.This part of work provides theoretical support and technical guidance for further refining nonlinear suppression scheme and carrying out nonlinear suppression experiments.Combined with the specific measurement environment and measurement requirements,the nonlinear phenomenon can be suppressed or eliminated,as the next step of CMF optimization design basis.