수평유로에서 분산 기포 유동의 국부적 계면 구조 특성에 대한 실험적 연구

Abstract

Phases and phasic velocity distributions in a horizontal pipe are asymmetric due to a density difference between the phases, while they are symmetric in a vertical pipe. The asymmetric phase distribution across the cross section in a horizontal bubbly flow due to a buoyancy can cause a flow pattern to change. Most experimental studies have been performed for the vertical pipes in which a symmetric phase distribution is formed, while few studies for bubbly flow at low flow rate have been performed for horizontal pipes. So a study about how overall bubbly flow changed is needed to perform. This study consists of two experiments. One experiment is performed to identify a horizontal two-phase flow pattern by using the ultrasonic sensor. The other is performed to understand phasic distributions in a horizontal channel. Required parameters are local void fraction, interfacial area concentration, Sauter mean diameter and bubbly velocity in this study. These parameters are measured by using the two-sensor conductivity probes. And the bubbly flow at several flow conditions is examined at a location, L/D = 154, in which represents near fully developed bubbly flow patterns. Based on the measured parameters, the phase distribution is experimentally analyzed.