Experimental study on pressure gradient for oil-air-water three-phase flow by means of a flow regime specific model through horizontal pipes

Experimental studies on characteristics of pressure drop for oil-air-water three-phase flow in horizontal pipes were conducted. The horizontal test section is made of 40 mm inner diameter plexiglas pipe. No.46 mechanical oil, air and tap water were used as working fluids. The superficial velocity ranges of oil, air and water were 0.05-0.51 m/s, 0.05-1.51 m/s and 0.02-50.6 m/s, respectively. According to the different structures of gas and liquids, typical flow patterns in horizontal pipe are divided into bubbly flow, intermitted flow (plug flow and slug flow), stratified flow and annular flow. The frictional pressure drop multiplier of three-phase flow was expressed using the Chisholm parameter correlation in accordance with typical flow pattern, but the modification factor C in the correlations was defined afresh according to flow conditions. New predict correlations for pressure gradient in accordance with typical flow patterns were proposed and the mechanisms of pressure drop production were analyzed for each flow patterns. The proposed models give a good agreement with the experimental data.