Development of an online measurement apparatus for the study of stratified flow in near-horizontal pipes

There is a high industrial interest today in the development of accurate measurement techniques to support the modelling of gas-liquid flow phenomena. When dealing with stratified flow in horizontal or inclined pipes, the main problem is that in the range of medium to large gas velocities there are very few data available for the development or validation of flow models. These data should include the measurement of the pressure gradient, the circumferential liquid film distribution, the liquid hold-up and the fraction of entrained droplets. This work describes the development and experimentation of a measurement set-up for generating these data at flow conditions as close as possible to those of industrial interest, in terms of pipe diameter and physical properties of the fluid. This paper focuses on the measurement technique, which is based on conductivity measurements by arrays of needle-shaped electrodes, and illustrates one practical implementation and its validation.