Numerical and experimental study of rotating stall in an axial compressor stage

A numerical study of rotating stall in a single-stage subsonic axial compre ssor is presented. The generation and the development of rotating stall sta rting from the peak of the stable branch of the compressor characteristic i s visualized and discussed. The structure and propagation of the fully deve loped rotating stall cell is analyzed for flow coefficients ranging from 58 to 70% of the design value. Prompted by previous analytical and experiment al studies stressing the importance of fluid inertia, the numerical analysi s is based on two-dimensional unsteady solutions of the Euler equations. Th e influence of the inlet and exit boundary conditions on the rotating staff pattern is assessed. The numerical solutions are validated against experim ental data consisting of Row visualization and unsteady row-by-row static p ressure measurements acquired in a four-stage water model of a subsonic axi al compressor, The results suggests that the essential Row physics governin g the structure and general mechanism of full-span rotating stall propagati on in low-speed axial compressors is captured by the present inviscid numer ical procedure.