Abstract: A method of making monolithic carbon nanotube heater elements with geometric shape with multiple, complex curvatures is disclosed. The method includes depositing carbon nanotubes on to a forming surface, draining the carbon nanotubes, and drying the carbon nanotubes. Alternatively, the method includes thermoforming carbon nanotube sheets containing thermoplastic binders. The resulting carbon nanotube heater element is a thin, monolithic carbon nanotube heater sheet having a geometric shape with complex curvatures.

Abstract: A method of determining wear of a seal element includes rotating a seal plate relative to the seal element and such that the seal plate and the seal element form a rotational sealing interface. The seal element includes an insert embedded in the seal element. A portion of the seal element is worn with a sealing face of the seal plate. The insert is contacted with the sealing face of the seal plate. A portion of the insert is worn to create a wear particle of the insert. The presence of the wear particle in a lubrication oil is sensed with an oil monitoring system.

Abstract: A bearing (20; 150; 152) comprises: an inner race (26); an outer race (28); and a plurality of rolling elements (30). The inner race comprises a nitrogen-alloyed steel (40). The outer race comprises a steel (42) with lower nitrogen content than said nitrogen-alloyed steel.

Abstract: An assembly for pivoting a flap according to an exemplary aspect of the present disclosure includes, among other things, a structure is mounted at least partially around an axis. The structure is attached to a pivotable flap arranged to define a nozzle area. A cable passes through an orifice defined by the flap. An actuator system is operable to mechanically retract the cable therein to lessen the nozzle area and mechanically extend the cable to enable the flow to increase the nozzle area. The actuator system is engaged with the cable. A segment of the cable, opposite the actuator system, is attached to a fixed structure. A method of providing a variable fan exit area is also disclosed.

Abstract: 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.

Abstract: A heat transfer system is disclosed that includes a circulation loop of a heat transfer fluid that comprises a halocarbon. The circulation loop includes a compressor or pump that includes bearing rolling surfaces in contact with the heat transfer fluid. The bearing contact surface has a substrate a layer thereon that includes a polymer or oligomer having polar side groups and a tribofilm.

Abstract: Methods and systems for health monitoring in an electrical mechanical system are provided. Aspects includes a controller coupled to a memory and one or more sensors affixed to an element of the electrical-mechanical system, wherein the one or more sensors comprise a power supply, wherein the one or more sensors are configured to collect sensor data responsive to detection of a vibration in the electrical-mechanical system above a threshold vibration, wherein the sensor data is associated with the element and transmit the sensor data to the controller, wherein the controller is configured to analyze the sensor data to determine a potential maintenance issue associated with the electrical-mechanical system.

Abstract: A piezoelectric sensor assembly for measuring a force quantity on a structure includes at least one piezoelectric sensor, each including an element and two electrodes each projecting outward from the element. An electronic processor of the assembly is configured to receive data from the sensor, wherein the data includes a voltage with a magnitude that is indicative of a dynamic load (i.e., amplitude modulation mode) placed upon the structure. The processor may be configured to interrogate the piezoelectric sensor for its resonant frequency change which is indicative of the load applied to the structure at low operation frequency and to which the piezoelectric sensor would not otherwise respond well. The dual mode operation of the piezoelectric sensor extends the frequency range of the strain measurement from the dynamic range to static or quasi-static range.

Abstract: A bearing (20; 150; 152) comprises: an inner race (26); an outer race (28); and a plurality of rolling elements (30). The inner race comprises a nitrogen-alloyed steel (40). The outer race comprises a steel (42) with lower nitrogen content than said nitrogen-alloyed steel.

Abstract: A compressor (22) has a housing assembly (40) with a suction port (24), a discharge port (26), and a motor compartment (60). An electric motor (42) has a stator (62) within the motor compartment and a rotor (64) within the stator. The rotor is mounted for rotation about a rotor axis (500). One or more working impellers (44) are coupled to the rotor to be driven by the rotor in at least a first condition so as to draw fluid in through the suction port and discharge the fluid from the discharge port. An inlet guide vane (IGV) array (174) is between the suction port (24) and the one or more impellers (44). One or more bearings (66, 68) support the rotor (64) and/or the one or more impellers (44). A purge unit (400) has a vapor inlet line (410) for receiving a refrigerant flow and a return line (414, 417A, 417B) for returning a contaminant-depleted refrigerant flow. A supply flowpath (407A, 407B) for supplying refrigerant to the bearings extends from the purge unit.

Abstract: A method of structural masking for progressive health monitoring of a structural component includes receiving a current image of the structural component. A processor aligns the current image and a reference image of the structural component. The processor performs a structure estimation on the current image and the reference image to produce a current structure estimate image and a reference structure estimate image. The processor generates a structural mask from the reference structure estimate image. The processor masks the current structure estimate image with the structural mask to identify one or more health monitoring analysis regions including a potential defect or damaged area appearing in the masked current structure estimate image that does not appear in the reference structure estimate image.

Abstract: A vapor compression system (20) comprises a compressor (22) having one or more bearing systems (66, 68) supporting a rotor and/or one or more working elements (44). One or more bearing feed passages (114) are coupled to the bearings to pass fluid along a supply flowpath to the bearings. A mechanical pump (130; 330) is positioned to drive fluid along the supply flowpath. An ejector (140, 150) has a motive flow inlet (142, 152) coupled to the mechanical pump to receive refrigerant from the mechanical pump.

Abstract: An erosion shield assembly includes an erosion shield, a carbon allotrope heater attached to an inner surface of the erosion shield, and an adhesive layer between the carbon allotrope heater and the erosion shield. The carbon allotrope heater includes at least one layer of a carbon allotrope material.

Abstract: An optical in-situ system for a gas turbine engine blade inspection comprises a camera configured to capture images of a forward surface of at least one gas turbine engine blade; and a processor coupled to the camera, the processor configured to determine damage to the at least one gas turbine engine blade based on image analytics.

Abstract: A carbon allotrope heating element includes an electrical resistivity between 0.005 ohms per square (?/sq) and 3.0 ?/sq. A heating system includes a component and a carbon allotrope heating element having an electrical resistivity between 0.005 ?/sq and 3.0 ?/sq. A method includes modifying a carbon allotrope heating element to have an electrical resistivity between 0.005 ?/sq and 3.0 ?/sq and applying the carbon allotrope heating element to a component of an aircraft.

Abstract: An illustrative example elevator assembly includes a frame having vertically oriented beams and horizontally oriented beams connected to the vertically oriented beams. A first elevator cab is supported within the frame between the vertically oriented beams. A pantograph linkage includes a plurality of links. The pantograph linkage is supported on one of the horizontally oriented beams. The pantograph linkage is connected with the first elevator cab such that different positions of the first elevator cab relative to the frame correspond to different relative positions of the links. A second elevator cab is suspended by the pantograph linkage beneath the frame. The different relative positions of the links place the second elevator cab in different positions relative to the frame.

Abstract: A method for fault diagnosis of a bearing includes detecting, using an oil debris monitor (ODM) sensor, ODM data corresponding to an amount of debris flowing downstream from the bearing. The method also includes detecting, using a vibration sensor, vibration data corresponding to vibration of the bearing during use. The method also includes determining, by a controller, a vibration stage flag corresponding to a severity of damage of the bearing based on the vibration data. The method also includes determining, by the controller, a severity level of the damage of the bearing based on a combination of the vibration stage flag and the ODM data. The method also includes outputting, by an output device, the severity level.

Abstract: A system for modulating turbine blade tip clearance is provided. The system may comprise an actuation control system having at least one actuator configured to modulate turbine blade tip clearance between a turbine blade tip and a blade outer air seal (BOAS). Each actuator may be coupled to the BOAS. Each actuator may comprise a solid-state motion amplification device such as a flextensional actuator. The actuators may be configured to move the BOAS in a radial direction from a first position to a second position to control tip clearance.

Abstract: A system for modulating turbine blade tip clearance is provided. The system may comprise an actuation control system having at least one actuator configured to modulate turbine blade tip clearance. Each actuator may comprise a solid-state motion amplification device such as a flextensional actuator. Each actuator may be in operable communication with a blade outer air seal (BOAS) segment or a BOAS mounting block. The actuators may be configured to move the BOAS segment and/or the BOAS mounting block in a radial direction from a first position to a second position to control tip clearance.

Abstract: A structural health monitoring module including a sensor attached to a surface of a structural member configured to convert a strain on the structural member to electric energy, a gate operationally connected to the sensor and configured to control distribution of the energy, an energy storage device operationally connected to the gate and configured to receive the energy from the sensor, a data collection device configured to receive the energy from the sensor and at least one of process and record data related to the received energy, and a data transmission device configured to wirelessly transmit data from the data collection device to an external receiver. The gate is configured to direct a portion of the energy to the storage device in a storage state and configured to direct a portion of the energy to the data collection device when in load monitoring or interrogation states.