Simulation Study on the Influence of Contraction Expansion and Bending Pipeline on Gas Flow Measurement Accuracy

Abstract

This paper conducts an analysis of three common types of typical disturbances encountered in industry, obtaining gas flow field distributions under different operating conditions through simulation studies. It further investigates their impact on the measurement errors of clamp-on ultrasonic flow meters. The study reveals that bend disturbances cause more significant distortion to the flow compared to expansion and contraction disturbances, necessitating longer downstream distances from the bend to achieve fully developed flow profiles. Additionally, at higher Reynolds numbers, the recovery rate of flow velocity profiles is slower, making it challenging to attain a fully developed flow state within short distances. Correction methods are required to reduce measurement errors. Correction factors at different distances downstream of the three disturbances are obtained through simulation, enabling higher precision measurements at relatively short distances downstream of disturbances. These findings hold significant implications for engineering practice