Abstract: Foreign object ingestion damage detection and accommodation system for a gas turbine engine system having a gas turbine engine with multiple rotating members, such as a twin spool configuration. System includes speed sensors for sensing the rotational speed of at least two rotating members. Sensors are coupled to a controller which detects damage by comparing the sensed speed of the second rotational member to an expected speed. Expected speed is determined from the sensed speed of the first rotating member using a known characteristic relationship between the the first and second rotating member speeds for the given gas turbine engine design. Thrust loss accommodation is triggered when damage is detected. Accommodation mode provides a synthesized primary thrust control feedback signal in lieu of the sensed signal for a damaged rotational member. Synthesized signal is derived from the sensed speed for the undamaged rotational member.

Abstract: A turbomachine including a case, a rotor, a plurality of rotor blades on the rotor each having a blade tip, a shroud around the rotor blade tips, and bearings mounting the rotor on the case for rotation about a centerline of the case and for bodily shiftable movement in the direction of the centerline. The rotor blade tips and an inside wall of the shroud flare radially outward in the direction of the centerline so that when the rotor moves in the direction of the centerline toward the shroud a clearance gap between the blade tips and the inner wall of the shroud decreases and vice versa. An electromagnetic actuator on the case magnetically attracts a thrust plate on the rotor against a net dynamic force on the rotor. A control system of the actuator controls the magnetic attraction of the actuator in response to signals from a position sensor measuring the actual magnitude of the clearance gap to maintain the actual clearance gap at a predetermined magnitude.