A theory of stall propagation in axial compressors on the basis of airfoil characteristics

Citation

Burggraf, Odus R (1955) A theory of stall propagation in axial compressors on the basis of airfoil characteristics. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/HQV0-7S12. https://resolver.caltech.edu/CaltechETD:etd-11242003-103851

Abstract

The process of stall propagation in an axial flow compressor is represented by nonlinear airfoil lift and drag characteristics, with a time lag associated with the stalling mechanism. A pair of nonlinear integro-differential equations express the lift and drag as a function of time for a given airfoil in an isolated plane cascade representing an annulus with only a finite number of blades. Approximate solutions of these integro-differential equations are obtained by considering only the fundamental frequency in the Fourier series representing the blade loadings. Qualitative results are obtained for three cases: (a) only blade circulation is considered to be of importance in the mechanism of propagating stall, (b) blade drag is of predominant importance, and (c) combined effects of lift and drag are considered. Comparisons are made of the propagating speeds calculated for a finite number of blades with the values obtained by the approximation of an infinite number of blades. The magnitudes of the fluctuations in lift and drag are calculated as well as limiting angles of attack for which stall propagation can occur.

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