Accession Number : ADA320147

Title :   Control of Compressor Rotating Stall without Distributed Sensing using Bifurcation Stabilization,

Corporate Author : WRIGHT LAB WRIGHT-PATTERSON AFB OH

Personal Author(s) : Sparks, Andrew G. ; Gu, Guoxiang

PDF Url : ADA320147

Report Date : 06 AUG 1996

Pagination or Media Count : 28

Abstract : Control of rotating stall in axial compressors is considered. A local bifurcation stabilization theorem using the projection method for the case of an uncontrollable, unobservable critical mode is described and extended to control laws that do not vanish at the critical or bifurcation point. This result is used to derive sufficient conditions for several control laws to guarantee that the subcritical pitchfork bifurcation of an axial compressor model is made supercritical so that the rotating stall hysteresis is eliminated. Each of the control laws considers operation at a set point distinct from the critical point and depends only on annulus-averaged quantities as feedback variables to simplify sensing and signal processing requirements. The actuation considered is a bleed valve so that the control law must be positive for all possible values of the feedback variables. It is shown that positive control is stabilizing for only some of the control laws considered. In these cases, numerical examples show the transformation of the bifurcation from subcritical to supercritical and the elimination of the hysteresis region. Finally, geometric interpretations of the effects of the feedback laws in the state space are described.

Descriptors :   *AXIAL FLOW COMPRESSORS, SIGNAL PROCESSING, REQUIREMENTS, DETECTION, DISTRIBUTION, REGIONS, VARIABLES, STALLING, FEEDBACK, VALVES, CONTROL THEORY, ROTATION, HYSTERESIS, BLEED SYSTEMS.

Subject Categories : Hydraulic and Pneumatic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE