Computational fluid dynamics modelling and validation of head losses in pipe bifurcations

Abstract

Manifold arrangements with bifurcations/trifurcations lead to head losses in a fluid system. It is necessary to predict the steady state head loss coefficients to characterise the losses arising due to these junctions. Miller [1] provides one of the most comprehensive sources for the junction loss coefficients data. However, these data were compiled from isolated research programmes without cross validation. This paper provides detailed quantitative data of sharp-edged bifurcation loss coefficients obtained using Computational Fluid Dynamics (CFD). ANSYS Design Modeller, ICEM and CFX software are used in conjunction to model and simulate flow of water through the pipe junctions. Loss coefficients at high Reynolds number (4.5 x 106) flows are investigated. These are expressed as a function of mass flow ratio, cross sectional area ratio and branch angle. In this study, 60 scenarios of pipe junction flows are investigated. The loss coefficients calculated using CFD are compared with measured values from experiments and empirical expressions reported in literature.