Annular diffuser for axial flow compressors - has downstream section divided into concentric rings allowing larger diffuser angle

摘要

Diffuser has an outer conically tapering side and an inner side tapering conically the other way so that the space between them is an annulus whose cross section increases axially. The angle of the annular diffusing cone so formed is greater than 7 deg. At a point in the axial direction before that at which the boundary layer would separate an intermediate annular sheet is interposed between the inner and outer sides. It divides the annulus into two concentric diffusing passages with a combined angle. This enables the angle of the diffuser to be greater than would otherwise be possible without boundary layer separation.