The Relationship between shape and Energy Loss of Rectangular Duct Branches Suitable for Production Rationalization

Abstract

Experiments were performed on rectangular take-off branch ducts of three types and eleven different shapes. Change in shape of the ducts has a small effect on the coefficient of branch loss of the main flow, but has a large effect on the loss of a branched flow. Chamfering the upstream side of the branch edge has a larger effect of making the coefficient of loss small than rounding the downstream side. This corner modeling effect on branch duct loss was confirmed also by tuft method. Based on these results, rectangular straight branch ducts furnished with installation faces were developed for the purpose of rationalizing the production and as well as modernizing and facilitating the manufacture.