Numerical and Experimental Study of Two-phase Flow in Downward vertical Pipe

In this study the flow patterns in downward air-water two-phase flow was studied experimentally and numerically. An experimental setup was designed and fabricated to allow visual observation and camera recording. The setup includes a transparent vertical pipe with a diameter of 50 mm and height of 4 m. Water and air were used in the experiments and flow map was prepared by data obtained from a total of 391 test cases by changing in air and water superficial velocities. Using flow pattern map, obtained from experimental results, simulation of two-phase flow in downward pipe has been performed. Multi-fluid model with Eulerian-Eulerian approach was used in Ansys-Fluent software for numerical simulation. Comparison of numerical with experimental results shows acceptable agreement for all expected regimes from flow map and it can be concluded that for downward two-phase flow patterns prediction numerical methods can be used. At the end, the numerical flow pattern map was plotted and compared with experimental results which also show good agreement. Experimental and numerical values of superficial velocities in transition boundaries were also compared.