Development of Small Rotating Stall in a Single Stage Axial Compressor

Abstract

In this paper we present the results of a detailed experimental study of the development of small rotating stall, as it appears in a one stage axial compressor. Stationary hot-wire probes are used to measure the variation of amplitude and propagation speed of the disturbances caused by small stall. Measurements near the rotor blade surface with rotating probes provide additional information on the nature of the phenomenon. The development of the cell pattern for different operating conditions is studied. The different character from what is known as “big stall” is demonstrated.

Pressure Fluctuation on Casing Wall of Isolated Axial Compressor Rotors at Low Flow Rate

“…Detailed experimental works have been made with improved measuring and analytical methods to elucidate the complex flow phenomena triggering to rotating stall. Reported so far are the existence of disturbances with different wave lengths rotating at speeds slightly lower than the rotor speed (Mathioudakis and Breugelmans: 1985), the occurrence of small stall cells travelling initially at near rotor speed and decelerating rapidly with growth in cell size (Jackson: 1987), the presence of a modal pre-stall wave propagating at a speed close to the fully developed stall cell speed (McDougall et al :1990, Gamier et al: 1991, and the coexistence of the formation of finite stall cells and the propagating pre-stall wave (Day: 1 991a).…”

Prediction of Small Rotating Stall in Axial Compressors Using Actuator Disc Theory

“…Expression (5) has been derived by using the rectan gular duct approximation only for the evaluation of the integrals I,J. If the approximation is used throughout the duct, the same relation holds with [ � evaluated at r = R eff• In this case [DJ x is a function of x only, while in the more general case of equation 5it is a function of x and r.…”

“…The second test case examined is theVKI R-1 low speed compressor. The geometry, performance characteristics and the unstable flow behaviour of this compressor have been described in [ 4,5]…”

“…"Small stall" consists of small amplitude fluctuations around a mean flow which keeps moving through the compressor. An experimental investigation of small stall was carried out in [ 5] and it was suggested that small perturbations theories could be used to predict this phenomenon. Such a theory is employed by the proposed method.…”

The Number and Speed of Stall Cells During Rotating Stall

“…The interpretation of the experimental data and calculation results play an important role in the analysis of the pressure and velocity fields during rotating stall. The number of stall cells mentioned in published experimental and theoretical studies of rotating stall may be one, two, three and even more (see for example Ciannissis et al, 1992, Day, I.J., 1992, Day and Freeman, 1994, Inoue et al, 2000, Inoue et al, 2002, Levy et al, 2002, Mathioudakis and Breugelmans, 1985, Poensgen and Gallus, 1996).…”