Review of droplet entrainment in annular flow: Characterization of the entrained droplets

This review analyzes most of the extensive literature on droplets, specifically analyzes its main characteristics once they have been formed, such as its sizes, speeds and total amount. A vast amount of data has been found in the open literature and collected here. Their analysis leads to two major observations: their huge scattering and the existence of remaining knowledge gaps. Some of the experimental data have been also used to derive new correlations on variables as important as amount and size of entrained droplets.