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: Convective cooling of gas turbine engine airfoil platforms is enhanced by grooving the interface of the platforms with corresponding platform-to-platform seals, thereby accelerating cooling airflow over the platform surfaces.

Abstract: Convective cooling of gas turbine engine airfoil platforms is enhanced by grooving the interface of the platforms with corresponding platform-to-platform seals, thereby accelerating cooling airflow over the platform surfaces.