Theoretical and Numerical Analysis of U-Tube Coriolis Mass Flowmeter with Liquid Hydrogen

Owing to its high accuracy,simple structure,and small flow resistance,the Coriolis mass flowmeter (CMF)is widely used in fluid measurement. In this study,the fluid-structure interaction vibration characteristics of a U-tube CMF with liquid hydrogen were investigated based on the coupling of computational fluid and computational structural dynamics and a flow-induced vibration model was established. The developed model and fluid-structure interaction framework were first validated based on a test rig for water. The standard mass flow rate in the experiment was obtained using a weighing method,and the phase difference between the two arms of the measuring tube was calculated using a designed control circuit. The comparison results revealed that the numerical simulation has a better prediction performance than the theoretical calculation based on the Euler beam model,in which the deviation of the numerical and theoretical results is -2.51% and -12.89%,respectively. Based on the verified numerical and Euler beam models,the influences of the mass flow rate and sensor positions on the time lag and vibration amplitude of a single U-tube CMF with liquid hydrogen were revealed. In addition,the effects of water and liquid hydrogen on the modal characteristics of the measuring tube were compared. Results showed that the additional mass of the fluid considerably influenced the modal characteristics of the measuring tube. Owing to the low density of liquid hydrogen, driving the tube with a dry mode frequency could achieve high driving efficiency,and the vibration amplitude of the measuring tube was about 17.75 times that of using water as the working fluid. However,the low-density and cryogenic characteristics of liquid hydrogen reduced the time lag,which was unfavorable for the high-precision measurement of the mass flow rate. In addition,the comparison of the theoretical and numerical results revealed that the effect of sensor position on time lag was affected by the mass flow rate. The findings of this study provide significant guidance for the optimal design of CMF with liquid hydrogen as the working fluid. © 2024 Tianjin University. All rights reserved.