Oil-water flows through sudden contraction and expansion in a horizontal pipe - Phase distribution and pressure drop

In this paper, change of flow patterns during the simultaneous flow of high viscous oil and water through the sudden contraction and expansion in a horizontal conduit has been studied. It is noted that these sudden changes in cross-section have a significant influence on the downstream phase distribution of lube oil-water flow. The observation suggests a simple technique to establish core flow as well as a way to prevent pipe wall fouling during the transportation of such oil. A number of interesting differences have been noted during low viscous oil-water flow through the same test rigs. While several types of core annular flow are observed for the former case, a wider variety of interfacial distribution characterizes kerosene-water systems. The pressure profiles during the simultaneous flow of lube oil and water through the sudden contraction and expansion are also studied and compared with low viscous oil-water flows. The pressure profiles are found to be independent of liquid viscosity and the loss coefficients are observed to be independent of flow patterns in both the cases.