Conversion of inlet temperature distortions to vorticity for an axial-flow compressor.

Abstract

A survey of the literature on pressure , temperature and foreign gas inlet distortions is made. For interpretation of the influence of inlet distortion on engine stability , a break is made with distortion methods which use temperature or pressure distortion maps . The distortion in the form of temperature contours is transformed to vorticity using appropriate equations derived for both incompressible and compressible flow. Crocco's theorem has been expanded in scope to include multispecie, nonuniform, perfect gas mixtures . The derivation of the equations and specialization to cases of interest involved a thorough order of magnitude analysis . A numerical solution of Poisson's equation as formulated by Squire and Winter to describe secondary flow arising from convected vorticity is presented. Deficient areas of knowledge relating to the general temperature/foreign gas problem are outlined . A conceptual mode l involving compressor stage transfer functions and feedback mechanisms is introduced and discussed at several points. Although not essential to understanding the vorticity stall logic chain , this mode l is a useful conceptual tool and may be worthy of additional study .