Uncertainty analysis of flow rate measurement for multiphase flow using CFD

• Published in: Acta mechanica Sinica Vol. 31; no. 5; pp. 698 - 707
• Main Authors: Kim, Joon-Hyung, Jung, Uk-Hee, Kim, Sung, Yoon, Joon-Yong, Choi, Young-Seok
• Format: Journal Article
• Language: English
• Published: Beijing The Chinese Society of Theoretical and Applied Mechanics; Institute of Mechanics, Chinese Academy of Sciences 25.09.2015
• Subjects: Classical and Continuum Physics; Computational Intelligence; Engineering; Engineering Fluid Dynamics; Research Paper; Theoretical and Applied Mechanics; 不均匀性; 不确定度分析; 多相流模型; 文丘里流量计; 文丘里管; 流动分析; 流量测量; 测量不确定度; Measurement; Uncertainty; Numerical analysis; Multiphase flow; Grace model; Multiphase flow model; Venturi meter; Gas volume fraction (GVF)
• ISSN: 0567-7718; 1614-3116
• DOI: 10.1007/s10409-015-0493-7

The venturi meter has an advantage in its use,because it can measure flow without being much affected by the type of the measured fluid or flow conditions.Hence,it has excellent versatility and is being widely applied in many industries.The flow of a liquid containing air is a representative example of a multiphase flow and exhibits complex flow characteristics.In particular,the greater the gas volume fraction（GVF）,the more inhomogeneous the flow becomes.As a result,using a venturi meter to measure the rate of a flow that has a high GVF generates an error.In this study,the cause of the error occurred in measuring the flow rate for the multiphase flow when using the venturi meter for analysis by CFD.To ensure the reliability of this study,the accuracy of the multiphase flow models for numerical analysis was verified through comparison between the calculated results of numerical analysis and the experimental data.As a result,the Grace model,which is a multiphase flow model established by an experiment with water and air,was confirmed to have the highest reliability.Finally,the characteristics of the internal flow Held about the multiphase flow analysis result generated by applying the Grace model were analyzed to find the cause of the uncertainty occurring when measuring the flow rate of the multiphase flow using the venturi meter.A phase separation phenomenon occurred due to a density difference of water and air inside the venturi,and flow inhomogeneity happened according to the flow velocity difference of each phase.It was confirmed that this flow inhomogeneity increased as the GVF increased due to the uncertainty of the flow measurement.