Two-Phase Flow Pattern of Air-Water with Low Viscosity in a 5-Degree Slope of a Capillary Pipe


  • Sukamta Sukamta Department of Mechanical Engineering, Faculty of Engineering, Universitas Muhammadiyah Yogyakarta, Jl. Brawijaya, Tamantirto, Kasihan, Bantul, Yogyakarta 55183, Indonesia


characteristics, pattern, superficial velocity, two-phase flow, viscosity


The main objective of this research is to find new information related to the characteristics of air-water two-phase flow patterns with low viscosity. In addition, this study also wants to prove that whether the pipe slope of 5 degrees affects the characteristics of the flow pattern map that occurs. The research was carried out using experimental methods, with an inner pipe diameter of 1.6 mm and a length of 130 mm. The test section with a slope of 5 degrees against the horizontal position. The working fluid being used was gas (air) and water mixed with glycerine at concentrations of 0%, 10%, 20%, 30% for each blend, and varying the superficial water and gas velocity in the range of JL = 0.033 to 4.935 m/s and JG = 0.025 to 66.3 m/s. The research was done by the method of visualization using a high-speed camera. The study found new five types of characteristics of flow pattern regarding bubbly, plug, slug annular, annular and churn. It was also found that the plug flow pattern dominates the result in this study, viscosity changes effect to be seen on the bubbly and plug flows as well as on the transition flow pattern. Flow patterns formed later are mapped based on superficial velocity variation. The map of the flow pattern is also compared to the results of previous research, and it has resulted in conformity.




How to Cite

Sukamta, S. (2021). Two-Phase Flow Pattern of Air-Water with Low Viscosity in a 5-Degree Slope of a Capillary Pipe. CFD Letters, 12(2), 115–123. Retrieved from