Loss and Discharge Characteristics of a Flow of Polymer Solutions through Pipe Orifices

Abstract

Loss and discharge characteristics and pressure distributions of a flow of polymer solutions through pipe orifices have been investigated experimentally. Three β ratios have been studied, and the measurements have covered both laminar and turbulent regions. The results have revealed how the differences in those characteristics between polymer solutions and water depend on β ratios and Reynolds numbers. In particular, it has been shown that the loss induced by orifices in turbulent region is reduced in polymer solutions compared to that in water. It has also been shown that the ratio of pressure loss to meter pressure differential is almost independent of fluids for high Reynolds numbers. Furthermore, some suggestions have been made on the position of the vena contracta, the coefficient of contraction, the relation to the Toms phenomenon and the loss upstream of the vena contracta.