Wire mesh sensor studies in a vertical pipe

A Wire Mesh Sensor system has been employed on a vertical 67 mm diameter pipe up which air and water mixtures flow. This enables an examination of the flow to be carried out at several levels of complexity. The measuring system provides time and cross-sectionally resolved information about the spatial distribution of the phases. The information can be used to obtain space and time averaged void fractions, radial profiles of time averaged void fraction and cross-sectional averaged time series of void fraction. This last yields Probability Density Function information as well as other statistical information. It also yields data of the frequency of periodic structures within the flow. More powerfully, the fully resolved data can give deep insights into the structure of the gas/liquid interface. A hitherto unreported structure has been seen in churn flow which could be linked to the wisps in wispy-annular flow.