Influence of Area Ratio On Flat Oval Divided-Flow Fitting Loss Coefficients

Abstract

A method of correlating branch loss coefficient data as a function of branch-to-common flow rate and area ratios is described. The algebraic expression that was used to successfully collapse the data from a given fitting geometry class onto a single curve was based on physical reasoning, and cannot be anticipated by conventional scaling arguments. The coefficients of empirical correlations were derived from previously published data and are tabulated for straight-body and conical tees and laterals. For flat oval fittings at a given flow rate ratio, as the area ratio increased the branch loss coefficient increased. At a given flow rate ratio, straight-body branches typically exhibited higher loss coefficients than conical branches, for the same flat oval branch-to-common area ratio. Tees consistently displayed higher branch loss coefficients than did laterals for the same flat oval branch/common geometry.