Correction of nonlinear measurement errors for non-invasive ultrasonic flowmeters under various operating conditions based on OpenFOAM-Python

Abstract Flow meters are critical in water management, chemical processing, and the civil transportation of water and gas. Ultrasonic flow meters (UFMs), known for their easy installation, high precision, and adaptability to various pipe diameters, are pivotal in velocity measurement applications. However, traditional UFMs that use the time difference method don’t account for the nonlinear effects of fluid velocity profiles, resulting in measurement inaccuracies. This study established an automatic flow-sound coupling non-invasive UFM correction velocity measurement system based on OpenFOAM-Python. The correction model considers comprehensive factors such as path length, propagation time, and angle differences caused by the actual S-shaped path of ultrasonic waves. The study introduces velocity profile generation, ray tracing model construction, and various measurement methods, validating their applicability. The simulation covers different pipeline diameters (DN 40 ~ 100) and Reynolds numbers (Re = 200 ~ 2e6) for both liquid and gas flows, analyzing ultrasonic propagation data. The improved model demonstrates higher accuracy and better handling of nonlinearity. The empirical formula was fitted for measurement nonlinearity within a specific range. These results provide crucial insights for designing precise flow measurement systems, enhancing efficiency in industrial and daily applications.