Flow of oil-water emulsion through constricted capillary tubes

The flow of oil-in-water emulsions through a constricted capillary tube was analyzed by experiments and theory. The experiments consisted of flow visualization and pressure drop measurements of the flow. A number of different emulsions were prepared using synthetic oils and deionized water. The average drop size varied from smaller to larger than the neck radius. Fluid mobility, defined as flow rate over pressure drop, was used to quantify the magnitude of the pore-blocking caused by drops larger than the constriction radius. The effect of the interfacial tension and viscosity ratio between the two phases on the changes of the local mobility was determined by solving the free surface flow of an infinite oil drop immersed in water flowing through a constricted capillary tube by Finite Element Method.