The effect of liquid viscosity on the gas-liquid two-phase flow pattern in horizontal mini-channel

The experimental studies on flow pattern of adiabatic gas-liquid two-phase flow in horizontally oriented mini-channel were conducted. The test section was a 1.6 mm inner diameter glass pipe. The range of gas and liquid superficial velocities were 0.025 - 66.3 m/s and 0.033 - 4.935 m/s, respectively. The working fluids were air and glycerol aqua solution in various percentage, 0%, 20%, 40%, and 60% indexed by W, G20, G40, and G60, respectively. The flow pattern data were obtained by analyzing the video images, captured by using the high-speed camera. As a result, it was found that the flow patterns observed in the present study were bubbly, plug, slug-annular, annular, and churn, while the stratified flow was not appeared. In the flow pattern map, the change of liquid viscosity affects to the shift of the transition line between flow pattern, particularly slug-annular to annular and slug-annular and annular to churn flow.