A gas turbine engine includes a harmonic drive driven by an actuator, a drive shaft driven by the harmonic drive, the drive shaft with a first drive gear and a second drive gear. A first variable vane stage with a first actuator gear to direct drive one of a multiple of variable vanes, the first actuator gear meshed with the first drive gear; and a second variable vane stage with a second actuator gear to direct drive one of a multiple of variable vanes, the second actuator gear meshed with the second drive gear.

A gas turbine engine including a core having in serial flow order a compressor, a combustor, and a turbine—the compressor, combustor, and turbine together defining a core air flowpath. The gas turbine engine additionally includes a fan section mechanically coupled to the core, the fan section including a plurality of fan blades, and each of the plurality fan blades defining a pitch axis. An actuation device is operable with the plurality fan blades for rotating the plurality fan blades about their respective pitch axes, the actuation device including an actuator located outward of the core air flowpath to, e.g., simplify the gas turbine engine.

A gas turbine engine including a core having in serial flow order a compressor, a combustor, and a turbine—the compressor, combustor, and turbine together defining a core air flowpath. The gas turbine engine additionally includes a fan section mechanically coupled to the core, the fan section including a plurality of fan blades, and each of the plurality fan blades defining a pitch axis. An actuation device is operable with the plurality fan blades for rotating the plurality fan blades about their respective pitch axes, the actuation device including an actuator located outward of the core air flowpath to, e.g., simplify the gas turbine engine.

There is provided a fluid control device included in a rotary machine including a rotor, a case provided to surround an outer side of the rotor, and seal fins each provided to protrude from at least one of the rotor or the case, and configured to control a swirling flow flowing between the seal fin and the rotor or between the seal fin and the case. The fluid control device includes a first fluid control device configured to generate an induced flow in a backflow direction opposite to a flow direction of the swirling flow in an axial direction of the rotor.

A semi-autonomous rapid response active clearance control system for a gas turbine engine includes an outer case, a carrier for a blade outer airseal positioned radially inward of the outer case, a blade outer airseal positioned radially inward of and mounted to the carrier, at least one electromechanical actuator attached to the outer case and selectively operable to move the carrier, and a sensing system. The sensing system includes a maneuver sensor housed within the actuator and configured to output a first signal, a position sensor mounted proximate to the blade outer airseal and configured to output a second signal, and a control means in communication with the maneuver sensor and the position sensor.

There is disclosed a centrifugal compressor including an impeller rotatable about an axis and a diffuser downstream of the impeller. The diffuser has walls delimiting flow passages. Plasma actuators are positioned adjacent the walls and are operatively connectable to a source of electricity. The plasma actuators have a first electrode, a second electrode, and a dielectric layer therebetween. The first electrode is upstream of the second electrode. The first electrode is exposed to the flow passage. The second electrode is shielded from the flow passage by the dielectric layer. The plasma actuators are operable to generate an electric field through the dielectric layer. The plasma actuators are located closer to inlets of the flow passage than to outlets of the flow passages. A method of operating the compressor is disclosed.

There is disclosed a centrifugal compressor including an impeller rotatable about an axis and a diffuser downstream of the impeller. The diffuser has walls delimiting flow passages. Plasma actuators are positioned adjacent the walls and are operatively connectable to a source of electricity. The plasma actuators have a first electrode, a second electrode, and a dielectric layer therebetween. The first electrode is upstream of the second electrode. The first electrode is exposed to the flow passage. The second electrode is shielded from the flow passage by the dielectric layer. The plasma actuators are operable to generate an electric field through the dielectric layer. The plasma actuators are located closer to inlets of the flow passage than to outlets of the flow passages. A method of operating the compressor is disclosed.

A morphing aerodynamic control surface geometry comprising a control surface having an articulated portion comprising a flexible skin coupled at an exterior of the articulated portion, the flexible skin comprising opposed interlocking elements sandwiched within a flexible polymer coupled to the interlocking elements; wherein the flexible skin is configured compliant responsive to an articulation of the articulated portion.

A morphing aerodynamic control surface geometry comprising a control surface having an articulated portion comprising a flexible skin coupled at an exterior of the articulated portion, the flexible skin comprising opposed interlocking elements sandwiched within a flexible polymer coupled to the interlocking elements; wherein the flexible skin is configured compliant responsive to an articulation of the articulated portion.

A vane arm assembly for a gas turbine engine is provided including: a vane arm having a first end, a second end opposite the first end, and an aperture proximate the second end, the aperture being defined by an aperture wall; a vane stem extending through the aperture of the vane arm; a mechanical fastener retaining a position of the vane arm in the longitudinal direction of the vane stem; and an impedance clip partially enclosing a portion of the second end of the vane arm to provide redundant position retention of the vane arm in the longitudinal direction of the vane stem.