Oil Water Flow Through Different Diameter Pipes: Similarities and Differences

A survey of the past literature shows that the studies on liquid–liquid flows have primarily been carried out in pipe diameters of 0.025 m or more and no significant influence of conduit size on flow patterns was reported. An interest is felt in the present work to extend the study to pipe diameters lower than 0.025 m and note the difference in the phase distribution (if any). The flow patterns are observed both visually and by photography in two test rigs of diameters 0.025 m and 0.012 m, respectively. The experiments indicate a marked influence of conduit size on flow patterns. The rivulet flow and the churn flow pattern are observed in the narrower pipe and the three-layer pattern which is noted in the 0.025 m pipe is absent in the latter case. The reason behind this has been attributed to the increased effect of surface tension and equilibrium contact angle in the narrow pipe. Additional efforts have been made to understand the influence of mixer design on the downstream flow patterns. It is noted that mixer design does influence the distribution of the two liquids and a properly designed mixer can increase or decrease the range of existence of any flow regime.