Design of an Experimental Setup for Two Phase Flow Studies in near Horizontal Upward and Downward Pipe Orientations

Abstract

Two phase flow has numerous industrial applications and some of them are related to transport of fluids, such as natural gas transportation. In which the pipe is not always horizontal and tends to be at upward or downward orientations. In the past decades, investigations have been conducted mostly in horizontal, vertical and upward flow. However, very little information is available for downward flows. An experimental setup was designed and constructed for the purpose of investigating heat transfer, pressure drop and void fraction for upward and downward flow. This investigation focused on two phase flow void fraction and flow visualization on a 25.4 mm diameter pipe for different downward flow inclinations. A flow map was developed for -5�, -10� and -20� of inclination describing the different flow pattern transition lines. A flow map comparison was performed between the flow map obtained in the present study and the one developed by Ghajar & Bhagwat (2014) for 12.7 mm pipe diameter pipe. The pipe diameter effect in the transition lines between different flow regimes was analyzed. An evaluation was conducted on thirteen well-known void fraction correlations available in the literature, where Gomez et al. (2000) showed the best performance overall. Also, a comparison of void fraction correlations performance for different pipe diameters was studied by comparing the results obtained in the present study with the results shown by Oyewole (2013) for a 12.7 mm pipe diameter. It was found that even though the pipe diameter is different, the performance of the selected void fraction correlations was analogous.