Measuring tube structure optimization of coriolis mass flowmeter with liquid hydrogen

Abstract

To improve the sensitivity of the Coriolis mass flowmeter (CMF) when measuring the mass flow rate of liquid hydrogen (LH2), this study investigates and compares the performance of measuring tubes with various shapes but identical lengths. The aim is to elucidate the mechanisms how the tube shapes affect the sensitivity of the CMF. An iterative fluid-structure interaction (FSI) calculation framework is developed on the ANSYS 2021R1 platform and validated using experimental results of water on a dual U-tube CMF. By employing the orthogonal test method in conjunction with numerical analysis, the tube structure is optimized. The variables considered for optimization include the length of the vertical and horizontal tubes, as well as the radius of the curved tube. Modal characteristics are analyzed, and their influence on the measurement performance of CMF is summarized. Additionally, the Coriolis force acting along the measuring tube, which is the primary factor causing the phase difference, is extracted to explore its impact. The results demonstrate that optimizing the measuring tube structure significantly increases measurement sensitivity, resulting in a larger phase difference. Furthermore, a dimensionless parameter is identified, exhibiting a strong correlation with measurement sensitivity. This parameter can serve as an approximation method for preliminary optimization of the measuring tube, effectively reducing the complexity of fluid-structure coupling calculations. More interestingly, the results of this research also indicated that the structural optimization results of the CMF with water and LH2 as the working fluids are the same.