High-gain feedback control of surge and rotating stall in axial flow compressors

The surge and rotating stall post-instability behaviors of axial flow compressors are investigated from a bifurcation-theoretic perspective, using a model and system data presented by Greitzer (1976a). For this model, a sequence of local and global bifurcations of the nonliner system dynamics is uncovered. This includes a global bifurcation of a pair of large-amplitude periodic solutions. Resulting from this bifurcation are a stable oscillation (“surge”) and an unstable oscillation (“anti-surge”). The latter oscillation is found to have a deciding significance regarding the particular post-instability behavior experienced by the compressor. These results are used to reconstruct Greitzer’s (1976b) findings regarding the manner in which post-instability behavior depends on system parameters. Although the model does not directly reflect nonaxisymmetric dynamics, use of a steady-state compressor characteristic approximating the measured characteristic of Greitzer (1976a) is found to result in conclusions that compare well with observation. Thus, the paper gives a convenient and simple explanation of the boundary between surge and rotating stall behaviors, without the use of more intricate models and analyses including nonaxisymmetric flow dynamics.

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Robustness of rotating stall control for axial-flow compressors

Proceedings of the 2002 American Control Conference (IEEE Cat. No.CH37301) ◽

10.1109/acc.2002.1025300 ◽

2002 ◽

Author(s):

A. Tahmasebi ◽

Xiang Chen

Keyword(s):

Axial Flow ◽

Rotating Stall ◽

Stall Control ◽

Axial Flow Compressors

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Turbomachinery Committee Best 1994 Paper Award: Dynamic Control of Rotating Stall in Axial Flow Compressors Using Aeromechanical Feedback

Journal of Turbomachinery ◽

10.1115/1.2835665 ◽

1995 ◽

Vol 117 (3) ◽

pp. 307-319 ◽

Cited By ~ 37

Author(s):

D. L. Gysling ◽

E. M. Greitzer

Keyword(s):

Control Strategy ◽

Dynamic Control ◽

Axial Flow ◽

Rotating Stall ◽

Operating Conditions ◽

Flow Coefficient ◽

Compression System ◽

Axial Flow Compressor ◽

Flow Compressor ◽

Axial Flow Compressors

Dynamic control of rotating stall in an axial flow compressor has been implemented using aeromechanical feedback. The control strategy developed used an array of wall jets, upstream of a single-stage compressor, which were regulated by locally reacting reed valves. These reed valves responded to the small-amplitude flow-field pressure perturbations that precede rotating stall. The valve design was such that the combined system, compressor plus reed valve controller, was stable under operating conditions that had been unstable without feedback. A 10 percent decrease in the stalling flow coefficient was obtained using the control strategy, and the extension of stable flow range was achieved with no measurable change in the steady-state performance of the compression system. The experiments demonstrate the first use of aeromechanical feedback to extend the stable operating range of an axial flow compressor, and the first use of local feedback and dynamic compensation techniques to suppress rotating stall. The design of the experiment was based on a two-dimensional stall inception model, which incorporated the effect of the aeromechanical feedback. The physical mechanism for rotating stall in axial flow compressors was examined with focus on the role of dynamic feedback in stabilizing compression system instability. As predicted and experimentally demonstrated, the effectiveness of the aeromechanical control strategy depends on a set of nondimensional control parameters that determine the interaction of the control strategy and the rotating stall dynamics.

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