Universal Gas-Liquid Flow Pattern Map and Its Use on Closure Relationship Selection

Abstract

Mechanistic modelling is a common approach to predict design parameters such as flow pattern, pressure drop, or liquid holdup in gas-liquid flow in pipes. This approach starts with the application of continuity and momentum balance and required supplementary relationships to close the system of the equations. These additional equations are also called closure relationships which are developed with experimental results for given conditions. These relationships evolved with time as researchers acquired experimental data under different conditions. Unfortunately, new closures are developed for the new conditions rather than universal relationships that can cover a wider set of conditions. This situation generates the need for a methodology that allows the inclusion of newly develop closures to increase the accuracy of the unified mechanistic models. This paper starts with a description of all the available two-dimension maps that can facilitate the visualization of the data. This allows the determination of regions where a particular set of closures minimize the discrepancy between calculated and measured parameters. This paper proposes a simplification of a modern solution to provide a simpler way to visualize the regions corresponding to a set of equations. The final proposed solution reveals a substantial reduction of the average discrepancy of the unified mechanistic model by selecting the most appropriate closures.