Abstract: Turbine engines are inspected by insertion of a zoom image or foveated image optical head through internal passages within the engine. The zoom image optical generates a first magnified image portion or a second image portion having a wider field of view and lower magnification. The foveated image optical head has a central first image portion having higher magnification that is included within and subtended by a second image portion having a wider field of view. The foveated or zoom image first and second image portions are separately simultaneously displayed on a common display, so that navigation position of the optical head and the magnified inspection image are correlated. In this way an inspector can confirm what area of interest within the turbine has been inspected while evaluating the adjacent magnified inspection image. The dual images correlation can be documented, such as by storing the simultaneously displayed images.

Abstract: Combustion or steam turbine engines internal areas of interest are inspected by insertion of a foveated image optical head through internal passages within the engine. The foveated image optical head has a central first image portion having higher magnification and smaller field of view that is included within and subtended by a second image portion having a wider field of view and lower magnification. The foveated image optical head facilitates maneuvering the borescope optical head through the turbine engine with the wider field of view second image portion to areas of interest, then performing a more detailed inspection by viewing the higher magnification first image portion. The optical head lenses are in fixed positions, sharing a single, common optical path and a common electronic image sensor. This lens and detector arrangement facilitates construction of a compact optical head, allowing passage through small diameter engine inspection ports.

Abstract: A system and a method for image acquisition suitable for use in a turbine engine are disclosed. Light received from a field of view in an object plane is projected onto an image plane through an optical modulation device and is transferred through an image conduit to a sensor array. The sensor array generates a set of sampled image signals in a sensing basis based on light received from the image conduit. Finally, the sampled image signals are transformed from the sensing basis to a representation basis and a set of estimated image signals are generated therefrom. The estimated image signals are used for reconstructing an image and/or a motion-video of a region of interest within a turbine engine.

Abstract: Apparatus and method for thermally mapping a component in a high temperature environment. An optical probe (10) has a field of view (14) arranged to encompass a surface of a component (15) to be mapped. The probe (10) captures infrared (IR) emissions in the near or mid IR band. An optical fiber (16) has a field of view to encompass a spot location (18) on the surface of the component within the field of view (14) of the probe (12). The fiber (16) captures emissions in the long IR band. The emissions in the long IR band are indicative of an emittance value at the spot location. This information may be used to calibrate a radiance map of the component generated from the emissions in the near or mid IR band and thus map the absolute temperature of the component regardless of whether the component includes a TBC.

Abstract: Combustion or steam turbine engines internal areas of interest are inspected by insertion of a foveated image optical head through internal passages within the engine. The foveated image optical head has a central first image portion having higher magnification and smaller field of view that is included within and subtended by a second image portion having a wider field of view and lower magnification. The foveated image optical head facilitates maneuvering the borescope optical head through the turbine engine with the wider field of view second image portion to areas of interest, then performing a more detailed inspection by viewing the higher magnification first image portion. The optical head lenses are in fixed positions, sharing a single, common optical path and a common electronic image sensor. This lens and detector arrangement facilitates construction of a compact optical head, allowing passage through small diameter engine inspection ports.

Abstract: Turbine engines are inspected by insertion of a zoom image or foveated image optical head through internal passages within the engine. The zoom image optical generates a first magnified image portion or a second image portion having a wider field of view and lower magnification. The foveated image optical head has a central first image portion having higher magnification that is included within and subtended by a second image portion having a wider field of view. The foveated or zoom image first and second image portions are separately simultaneously displayed on a common display, so that navigation position of the optical head and the magnified inspection image are correlated. In this way an inspector can confirm what area of interest within the turbine has been inspected while evaluating the adjacent magnified inspection image. The dual images correlation can be documented, such as by storing the simultaneously displayed images.

Abstract: Optical camera systems for nondestructive internal inspection of online, operating power generation turbines, including gas turbine combustor and turbine sections that are at high operating temperatures in the range of over 600° C. (1112° F.). The system includes one or more temperature and vibration-compensating lens systems in the optical tube mount. The lens is circumferentially retained within a lens mount, with a mounting ring in contact with only the lens axial face. A biasing element exerts axially oriented biasing force on the first lens face through the first mounting ring, allowing for mount flexure in response to operational turbine vibration and temperature changes. The lens mount is advantageously combined with aspheric lenses capable of withstanding continuous operating temperatures above 600° C. The aspheric lenses, alone or in combination with spherical lenses, establish a wider field of view, and require fewer lenses in combination than lens mounts incorporating only spherical lenses.

Abstract: Operational gas turbine engine housing or casing dynamic strain, temporary or permanent displacement and/or temperature is measured by a distributed fiber optic sensing system (DFOSS) utilizing optical frequency domain reflectometry (OFDR) that is coupled to the turbine engine housing. The DFOSS/OFDR system measures localized variances in strain along the length of an optical fiber (OF), which are correlated with turbine engine housing displacement. Temperature influence on the measured localized strain variances is accounted for by obtaining temperature information from an another measurement system or by taking the same type OFDR measurements on unrestrained optical fiber (OF) and deriving compensated strain measurements that are not temperature influenced. The derived strain measurements along the DFOSS are correlated with housing displacement. Other embodiments include separate displacement measuring modules, each including DFOSS optical fibers, coupled along the engine housing.

Abstract: An optical inspection system for nondestructive internal visual inspection and non-contact infra-red (IR) temperature monitoring of an online, operating power generation turbine. The optical inspection system includes an optical tube having a viewing port, at least one reflective mirror or a mirror array having a reflectivity spectral range from 550 nm to 20 ?m, and capable of continuous operation at temperatures greater than 932 degrees Fahrenheit (500 degrees Celsius), and a transparent window with high transmission within the same spectral range mounted distal the viewing port. The same optical mirror array may be used to measure selectively surface temperature of metal turbine blades in the near IR range (approximately 1 ?m wavelength) and of thermal barrier coated turbine blades in the long IR range (approximately 10 ?m wavelength).

Abstract: Operational gas turbine engine housing or casing dynamic strain, temporary or permanent displacement and/or temperature is measured by a distributed fiber optic sensing system (DFOSS) utilizing optical frequency domain reflectometry (OFDR) that is coupled to the turbine engine housing. The DFOSS/OFDR system measures localized variances in strain along the length of an optical fiber (OF), which are correlated with turbine engine housing displacement. Temperature influence on the measured localized strain variances is accounted for by obtaining temperature information from an another measurement system or by taking the same type OFDR measurements on unrestrained optical fiber (OF) and deriving compensated strain measurements that are not temperature influenced. The derived strain measurements along the DFOSS are correlated with housing displacement. Other embodiments include separate displacement measuring modules, each including DFOSS optical fibers, coupled along the engine housing.

Abstract: Apparatus and method for thermally mapping a component in a high temperature environment. An optical probe (10) has a field of view (14) arranged to encompass a surface of a component (15) to be mapped. The probe (10) captures infrared (IR) emissions in the near or mid IR band. An optical fiber (16) has a field of view to encompass a spot location (18) on the surface of the component within the field of view (14) of the probe (12). The fiber (16) captures emissions in the long IR band. The emissions in the long IR band are indicative of an emittance value at the spot location. This information may be used to calibrate a radiance map of the component generated from the emissions in the near or mid IR band and thus map the absolute temperature of the component regardless of whether the component includes a TBC.

Abstract: Two adjacent objects with a gap between the objects rotate in a hot atmosphere with a temperature greater than 300 F in a gas turbine. Automatic and accurate contactless measurement of the gap is performed by taking images of the gap. An image, preferably an infra-red image is taken from the gap, a processor extracts the two edges from the image of the gap. The processor also determines a line through the pixels of an edge by applying a Hough transform on the pixels. The edges are substantially parallel. A line substantially perpendicular to the lines is also determined. Using the substantially parallel lines and the line substantially perpendicular to the substantially parallel lines the processor determines a width of the gap.

Abstract: A system and a method for image acquisition suitable for use in a turbine engine are disclosed. Light received from a field of view in an object plane is projected onto an image plane through an optical modulation device and is transferred through an image conduit to a sensor array. The sensor array generates a set of sampled image signals in a sensing basis based on light received from the image conduit. Finally, the sampled image signals are transformed from the sensing basis to a representation basis and a set of estimated image signals are generated therefrom. The estimated image signals are used for reconstructing an image and/or a motion-video of a region of interest within a turbine engine.

Abstract: Optical camera systems for nondestructive internal inspection of online, operating power generation turbines, including gas turbine combustor and turbine sections that are at high operating temperatures in the range of over 600° C. (1112° F.) and which include combustion gas contaminants. The inspection system includes one or more aspheric lenses capable of withstanding continuous operating temperatures above 600° C. The aspheric lenses, alone or in combination with spherical lenses, establish a wider field of view, and require fewer lenses in combination than lens mounts incorporating only spherical lenses. A cooling system incorporated in the inspection system facilitates continuous operation and inhibits lens external surface fouling from combustion gasses.

Abstract: A method of nondestructive evaluation and related system. The method includes arranging a test piece (14) having an internal passage (18) and an external surface (15) and a thermal calibrator (12) within a field of view (42) of an infrared sensor (44); generating a flow (16) of fluid characterized by a fluid temperature; exposing the test piece internal passage (18) and the thermal calibrator (12) to fluid from the flow (16); capturing infrared emission information of the test piece external surface (15) and of the thermal calibrator (12) simultaneously using the infrared sensor (44), wherein the test piece infrared emission information includes emission intensity information, and wherein the thermal calibrator infrared emission information includes a reference emission intensity associated with the fluid temperature; and normalizing the test piece emission intensity information against the reference emission intensity.

Abstract: Method and system for calibrating a thermal radiance map of a turbine component in a combustion environment. At least one spot (18) of material is disposed on a surface of the component. An infrared (IR) imager (14) is arranged so that the spot is within a field of view of the imager to acquire imaging data of the spot. A processor (30) is configured to process the imaging data to generate a sequence of images as a temperature of the combustion environment is increased. A monitor (42, 44) may be coupled to the processor to monitor the sequence of images of to determine an occurrence of a physical change of the spot as the temperature is increased. A calibration module (46) may be configured to assign a first temperature value to the surface of the turbine component when the occurrence of the physical change of the spot is determined.

Abstract: An optical inspection system for nondestructive internal visual inspection and non-contact infra-red (IR) temperature monitoring of an online, operating power generation turbine. The optical inspection system includes an optical tube having a viewing port, at least one reflective mirror or a mirror array having a reflectivity spectral range from 550 nm to 20 ?m, and capable of continuous operation at temperatures greater than 932 degrees Fahrenheit (500 degrees Celsius), and a transparent window with high transmission within the same spectral range mounted distal the viewing port. The same optical mirror array may be used to measure selectively surface temperature of metal turbine blades in the near IR range (approximately 1 ?m wavelength) and of thermal barrier coated turbine blades in the long IR range (approximately 10 ?m wavelength).

Abstract: A method of nondestructive evaluation and related system. The method includes arranging a test piece (14) having an internal passage (18) and an external surface (15) and a thermal calibrator (12) within a field of view (42) of an infrared sensor (44); generating a flow (16) of fluid characterized by a fluid temperature; exposing the test piece internal passage (18) and the thermal calibrator (12) to fluid from the flow (16); capturing infrared emission information of the test piece external surface (15) and of the thermal calibrator (12) simultaneously using the infrared sensor (44), wherein the test piece infrared emission information includes emission intensity information, and wherein the thermal calibrator infrared emission information includes a reference emission intensity associated with the fluid temperature; and normalizing the test piece emission intensity information against the reference emission intensity.

Abstract: Inspecting a turbine includes positioning respective ends of a plurality of optical fibers within a high temperature region of the turbine wherein the respective first ends are aligned as a one-dimensional array. Energy emitted from an image area on a component of the turbine, is received at the ends of the optical fiber. The optical fibers convey the received energy to the other ends of the fibers that are located outside of the turbine. Outside the turbine an image of the respective other ends is captured, wherein the other ends are also aligned in a one-dimensional area. Additionally, for imaging a rotating component, a plurality of one-dimensional images of the other ends can be respectively captured at corresponding rotational positions of the component and used to create a two-dimensional image of the rotating component.

Abstract: Inspecting a turbine includes positioning respective ends of a plurality of optical fibers within a high temperature region of the turbine wherein the respective first ends are aligned as a one-dimensional array. Energy emitted from an image area on a component of the turbine, is received at the ends of the optical fiber. The optical fibers convey the received energy to the other ends of the fibers that are located outside of the turbine. Outside the turbine an image of the respective other ends is captured, wherein the other ends are also aligned in a one-dimensional area. Additionally, for imaging a rotating component, a plurality of one-dimensional images of the other ends can be respectively captured at corresponding rotational positions of the component and used to create a two-dimensional image of the rotating component.