Data from: Reconstruction of velocity fields in electromagnetic flow tomography

Electromagnetic flow meters (EMFMs) are the gold standard in measuring flow velocity in process industry. The flow meters can measure the mean flow velocity of conductive liquids and slurries. A drawback of this approach is that the velocity field cannot be determined. Asymmetric axial flows, often encountered in multiphase flows, pipe elbows and T-junctions, are problematic and can lead to serious systematic errors. Recently, electromagnetic flow tomography (EMFT) has been proposed for measuring velocity fields using several coils and a set of electrodes attached to the surface of the pipe. In this work, a velocity field reconstruction method for EMFT is proposed. The method uses a previously developed finite-element-based computational forward model for computing boundary voltages and a Bayesian framework for inverse problems. In the approach, the vz-component of the velocity field along the longitudinal axis of the pipe is estimated on the pipe cross section. Different asymmetric velocity fields encountered near pipe elbows, solids-in-water flows in inclined pipes and in stratified or multiphase flows are tested. The results suggest that the proposed reconstruction method could be used to estimate velocity fields in complicated pipe flows in which the conventional EMFMs have limited accuracy.电磁流量计（Electromagnetic flow meters, EMFMs）是过程工业中测量流体流速的金标准。这类流量计可测量导电液体与浆体的平均流速，但该方法存在固有缺陷：无法获取完整的速度场分布。在多相流、管道弯头及T型接头场景中常见的不对称轴向流会引发严重系统误差，严重影响测量精度。近年来，研究人员提出了电磁流量层析成像（Electromagnetic flow tomography, EMFT）技术，通过安装于管道表面的多组线圈与电极阵列来重建流速场。本研究提出了一种面向EMFT的速度场重建方法：该方法依托此前开发的基于有限元的计算正演模型求解边界电压，并采用贝叶斯框架处理逆问题。本方法针对管道横截面，估算沿管道纵轴的速度场z向分量（vz）。研究测试了多种典型非对称速度场场景，包括管道弯头附近流场、倾斜管道内的固水两相流以及分层流或多相流工况。实验结果表明，所提重建方法可用于估算常规EMFMs精度受限的复杂管道流场速度分布。