A Review of Drag Coefficient Models in Gas‐Liquid Two‐Phase Flow

Abstract Although great efforts have been made in modeling the drag force in gas‐liquid two‐phase flow, the research about that in both theory and method is at the stage of development due to its diversity and complexity, and previous summary work about drag is usually based on a certain aspect. In this review, a unified framework that guides the drag coefficient model in gas‐liquid two‐phase flow is provided. From simple to complex, this paper introduces the drag coefficient of solid particles, single bubbles, bubble swarms, and bubbles in turbulence moving in liquid in turn. The variables affecting the drag coefficient in each of the above situations and the relationship between the drag coefficient and these variables are mentioned.