The Effect of Liquid Viscosity on The Gas-Liquid Two-Phase Flow Pattern in 45o Inclined Capillary Pipe

Abstract

The experiment on flow pattern of gas-liquid two-phase flow in 45o inclined capillary channel was carried-out. The motivation was to obtain primary data and information of two-phase flow characteristics especially flow pattern. The test section was a 1.6 mm inner diameter and 130 mm length circular glass pipe, equipped with the optical correction box. A perpendicular entrance type mixer was used to mix both gas and liquid phase working fluids prior to test section. The high-speed camera was used to capture the two-phase flow. The captured video images were then analyzed to obtain the flow pattern. The range of gas and liquid superficial velocities were 0.025 - 66.3 m/s, and 0.033 - 4.935 m/s, respectively. The gas fluid was represented by dry air, while that of liquid was glycerol-aqua solution in various percentage, i.e. 0%, 10%, 20%, and 30%. The addition of glycerin to the liquid phase was intended to vary the liquid viscosities. As a result, it was found that both gas and liquid superficial velocities affected significantly to the two-phase flow configuration. Five flow patterns, namely: plug, slug-annular, churn, bubbly, and annular were observed, while the stratified flow was not obtained. The change of liquid viscosity affected to the configuration of flow pattern, especially in the liquid film thickness in annular flow and plug size and frequency in plug flow. Liquid viscosity also influenced to the shift of the transition line between flow patterns in the flow pattern map. The transition line between slugannular flow and churn flow was shifted upper side when the liquid viscosity was increased. This condition caused by lower turbulence for higher liquid viscosity.