Abstract: An environmental sampling system includes a passage in an aircraft component and a removable collector disposed in the passage. The passage has an inlet at a first region and an outlet at a second region. When the aircraft component is in operation the first region is at a greater pressure than the second region such that air flows through the passage from the inlet to the outlet. The removable collector is configured to retain constituents from the air and to react with the media designed to mimic corrosion effects seen at higher temperatures on engine parts. The constituents can then be characterized and correlated to engine deterioration to predict maintenance activity.

Abstract: A sensor assembly for a gas turbine engine according to an example of the present disclosure includes, among other things, a substrate layer formed on a localized surface of a rotatable gas turbine engine component, and at least one pair of transducers deposited on the substrate layer.

Abstract: An environmental sampling system includes a passage in an aircraft component and a removable collector disposed in the passage. The passage has an inlet at a first region and an outlet at a second region. When the aircraft component is in operation the first region is at a greater pressure than the second region such that air flows through the passage from the inlet to the outlet. The removable collector is configured to retain constituents from the air and to react with the media designed to mimic corrosion effects seen at higher temperatures on engine parts. The constituents can then be characterized and correlated to engine deterioration to predict maintenance activity.

Abstract: An aeromechanical identification system for turbomachine includes at least one actuator mounted on a stationary structure to excite rotatable airfoils. At least one sensor is mounted proximate the airfoils for measuring a response of the airfoils responsive to excitation from the at least one actuator. A controller is configured to determine a damping characteristic of an aeromechanical mode of the rotating airfoils based on the excitation and the response. A gas turbine engine and a method of determining a flutter boundary for an airfoil of a turbomachine are also disclosed.

Abstract: A sensor assembly for a gas turbine engine according to an example of the present disclosure includes, among other things, a substrate layer formed on a localized surface of a rotatable gas turbine engine component, and at least one pair of transducers deposited on the substrate layer.

Abstract: A system includes a turbomachine having one or more inspection ports. An LWIR sensor is positioned in the inspection port of the turbomachine to sense thermal energy emitted by a turbomachine component. An imaging device can be operably connected to the LWIR sensor to convert signals from the LWIR sensor to a thermal image of the turbomachine component based on the sensed thermal energy. In some embodiments, the LWIR sensor configured to image a ceramic coated turbine blade.

Abstract: An aeromechanical identification system for turbomachine includes at least one actuator mounted on a stationary structure to excite rotatable airfoils. At least one sensor is mounted proximate the airfoils for measuring a response of the airfoils responsive to excitation from the at least one actuator. A controller is configured to determine a damping characteristic of an aeromechanical mode of the rotating airfoils based on the excitation and the response. A gas turbine engine and a method of determining a flutter boundary for an airfoil of a turbomachine are also disclosed.

Abstract: A method for thermally imaging a moving workpiece of a gas turbine engine comprises identifying a plurality of geometric features to construct a composite image. The geometric features include at least one integral thermal feature of the moving workpiece, and at least one artificial feature applied to the workpiece for diagnostic purposes. One of the plurality of geometric features is identified as a master feature, and the remainder of the plurality of geometric features are located relative to the master feature with relative actual coordinates. A pixel location of the master feature is identified or each image, and the remainder of the plurality of geometric features are located relative to the master feature with relative pixel coordinates. Offset, rotation, and scaling of the secondary images are varied to minimize a relative difference between the relative pixel coordinates and the relative actual coordinates.

Abstract: A method for thermally imaging a moving workpiece of a gas turbine engine using long wavelength infrared (LWIR) images of the workpiece captured during operation of the gas turbine engine. The method comprises determining average pixel intensity and pixel variation in intensity for each pixel across the plurality of LWIR images, determining average area intensity and area variation in intensity across a range of areas defined by increasing length scales about a selected pixel, and identifying as a critical length scale a length scale at which area variation in intensity is minimized as a function of length scale, for which the area intensity remains substantially the same as the average pixel intensity of the selected pixel. A composite image is built such that each pixel of the composite image has intensity equal to an average area intensity centered on that pixel, over the critical length scale.

Abstract: A method for thermally imaging a moving workpiece of a gas turbine engine comprises identifying a plurality of geometric features to construct a composite image. The geometric features include at least one integral thermal feature of the moving workpiece, and at least one artificial feature applied to the workpiece for diagnostic purposes. One of the plurality of geometric features is identified as a master feature, and the remainder of the plurality of geometric features are located relative to the master feature with relative actual coordinates. A pixel location of the master feature is identified or each image, and the remainder of the plurality of geometric features are located relative to the master feature with relative pixel coordinates. Offset, rotation, and scaling of the secondary images are varied to minimize a relative difference between the relative pixel coordinates and the relative actual coordinates.

Abstract: A method for thermally imaging a moving workpiece of a gas turbine engine using long wavelength infrared (LWIR) images of the workpiece captured during operation of the gas turbine engine. The method comprises determining average pixel intensity and pixel variation in intensity for each pixel across the plurality of LWIR images, determining average area intensity and area variation in intensity across a range of areas defined by increasing length scales about a selected pixel, and identifying as a critical length scale a length scale at which area variation in intensity is minimized as a function of length scale, for which the area intensity remains substantially the same as the average pixel intensity of the selected pixel. A composite image is built such that each pixel of the composite image has intensity equal to an average area intensity centered on that pixel, over the critical length scale.

Abstract: A system includes a turbomachine having one or more inspection ports. An LWIR sensor is positioned in the inspection port of the turbomachine to sense thermal energy emitted by a turbomachine component. An imaging device can be operably connected to the LWIR sensor to convert signals from the LWIR sensor to a thermal image of the turbomachine component based on the sensed thermal energy. In some embodiments, the LWIR sensor configured to image a ceramic coated turbine blade.