Generation of Entrained Droplets from an Imitated Disturbance Wave and their Deposition on the Wall.

Abstract

Gas-liqudid annular two-phase flow is an important flow pattern in terms of the liquid film dryout at the high quality region in various kinds of heat exchangers. In the past, many investigations on an annular-dispersed flow in horizontal pipelines were conducted, and the behaviors of entrained droplets have been discussed. They, however, focussed only on spatially averaged values of various properties of the droplets. In the present experiment, an isokinetic sampling probe technique was used for the measurement of the droplet flow rate generated from an imitated disturbance wave which constructed by injecting liquid through a slit mounted on the bottom of a horizontal duct. The experimental data on the distribution of entrained droplets and their deposition on the duct wall are presented. As a result, it is clarified that the distribution of the droplet flow rate is not uniform axially and in the direction of height and is actually nonsteady. Furthermore, the correlation of the entrainment fraction proposed by Paleev-Filippovich is superior to that by others.