A Study on the Characterization of Air-water Two-phase Vertical Flow by Using Electrical Resistance Imaging

Y Wu1, H Li1, M Wang2 and R A Williams2

1 Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100080, P.R. China, yxwu@imech.ac.cn

2 Institute of Particle Science and Engineering, University of Leeds, LS2 9JT, UK, m.wang@leeds.ac.uk

ABSTRACT

The characterization of air-water two-phase vertical flow in a 12 m flow loop with 1.5 m of vertical section is studied by using an impedance image based method of electrical resistance tomography (ERT). The flow patterns of bubbly flow, slug flow and churn flow and their transitions of the vertical flow exit a jet pump in a short distance are imaged by ERT technique. The mixing process, especially the turbulent blending process, of gas and liquid phases is observed and analyzed. By applying a fast data collection to a dual-plane ERT sensor and an iterative image reconstruction algorithm, relevant information is gathered for implementation of flow characteristics, particularly for flow regime recognition. Cross-correlation method is also used to interpret the velocity distribution of the gas phase on the cross section. The paper demonstrates that ERT can now be deployed routinely for velocity measurements and this capability will increase as faster measurement systems evolve.

Keywords ERT, gas-liquid two-phase flow, vertical flow, velocity measurement