Studies on Performance and Internal Flow of Twisted S-Shaped Bend Diffuser—The So-Called Coiled Bend Diffuser: 1st Report

Abstract

This paper is the result of our research into the twisted S -shaped bend diffuser—the so-called coiled bend diffuser. It is a diffuser with a centerline in the shape of a twisted “S .” Our studies show that the performance characteristics of this bend diffuser are greatly improved when interaction by the bend elements generates an adequate secondary flow inside the diffuser. Full consideration was given to the influence of the divergent angle of the bend elements, consisting of the diffuser or curvature radius ratio of the bend, on these performance characteristics. The relation between diffuser performance and internal flow also was studied. Some guidelines for designing such a high performance diffuser is given.