Abstract
Passive cyclonic gas-liquid separators (PCGLSs) are commonly used in microgravity conditions where gravity settling separation is difficult or impossible. In this study, displacement-current phase tomography (DCPT) is used to measure various features of the gas-liquid flow inside of a PCGLS. The liquid holdup, liquid angular velocity, and gas core size are investigated. The liquid holdup is also measured in a gas-liquid flow that simulates the injection flow for a PCGLS. It is found that the gas core contracts and expands in a periodic motion as air is injected with water. This motion becomes more noticeable as the air flow rate is increased. It is also found that the liquid layer angular velocity has a positive linear trend with the air flow rate under constant water flow rates. A basic linear relation is derived to relate the liquid angular velocity to the air and water flow rates. All DCPT and electrical capacitance phase tomography (ECVT) results closely match the visual confirmation methods used for each flow feature.