Abstract: A fiber grating temperature sensor includes a hollow tube, an optical fiber disposed in the hollow tube such that a gap exists between at least a portion of an internal surface of the hollow tube and an exterior surface of the optical fiber. The optical fiber includes at least one Bragg grating. A lubricant is disposed within the hollow tube, between the exterior surface of the fiber and the interior surface of the hollow tube.

Abstract: According to an aspect, a bowed rotor sensor system for a gas turbine engine is provided. The bowed rotor sensor system includes a bowed rotor sensor operable to transmit a sensing field in an observation region and receive a signal indicative of a gap between an air seal and a blade tip within the gas turbine engine. The bowed rotor sensor system also includes a controller operable to monitor a plurality of gap data from the bowed rotor sensor indicative of the gap between the air seal and the blade tip of a plurality of blades passing through the observation region and determine a bowed rotor status of the gas turbine engine based on the gap data.

Abstract: In various embodiments, the present disclosure provides a probe seating and locking device comprising a main body and a sleeve disposed at least partially concentrically about a probe. In various embodiments, the main body comprises a relief cut, a probe channel in communication with the relief cut, and a probe housing extending from the main body, wherein the probe housing has a probe passage in communication with the probe channel. In various embodiments, the probe passage comprises a first end, a second end, and a sensing aperture, wherein the probe housing is coupled to the main body at the first end. In various embodiments, the probe is disposed in the probe channel and is in contact with the seating step.

Abstract: According to an aspect, a bowed rotor sensor system for a gas turbine engine is provided. The bowed rotor sensor system includes a bowed rotor sensor operable to transmit a sensing field in an observation region and receive a signal indicative of a gap between an air seal and a blade tip within the gas turbine engine. The bowed rotor sensor system also includes a controller operable to monitor a plurality of gap data from the bowed rotor sensor indicative of the gap between the air seal and the blade tip of a plurality of blades passing through the observation region and determine a bowed rotor status of the gas turbine engine based on the gap data.

Abstract: A method for configuring a sensor of a non-interference stress management system is disclosed. The method may include determining a focal distance between a light transmitting fiber and a transmit lens, the focal distance configured to focus light from the transmit fiber to form a focused transmit beam, the transmit beam targeting a reflective structure. The method may further include positioning the light transmitting fiber and the transmit lens, wherein the light transmitting fiber and the transmit lens are separated by a transmit gap based on the focal distance and positioning a light receptive fiber and a receive lens to receive a focused reflected beam from the reflective structure, wherein the light receptive fiber is separated from the receive lens by a receive gap based on the focal distance.

Abstract: In various embodiments, the present disclosure provides a probe seating and locking device comprising a main body and a sleeve disposed at least partially concentrically about a probe. In various embodiments, the main body comprises a relief cut, a probe channel in communication with the relief cut, and a probe housing extending from the main body, wherein the probe housing has a probe passage in communication with the probe channel. In various embodiments, the probe passage comprises a first end, a second end, and a sensing aperture, wherein the probe housing is coupled to the main body at the first end. In various embodiments, the probe is disposed in the probe channel and is in contact with the seating step.

Abstract: A phosphor thermometer is disclosed. The phosphor thermometer may comprise a light source configured to emit an excitation light, and an input waveguide configured to transmit at least a portion of the excitation light from the light source to a temperature sensing end. A phosphor may be located at the temperature sensing end and it may be configured to emit a fluorescence signal upon absorption of at least a portion of the excitation light transmitted by the input waveguide. The phosphor thermometer may further comprise an output waveguide configured to transmit at least a portion of the fluorescence signal from the phosphor to a detector. The detector may determine a fluorescence decay constant from the time dependent decay of the fluorescence signal, and the fluorescence decay constant may be correlated with a temperature.

Abstract: A gas turbine engine includes a compressor section, a combustor section and a turbine section mounted relative to an engine static structure. A module includes instrumentation that is mounted to the engine static structure. The module includes an energy harvesting power source that is configured to provide electricity to the instrumentation during engine operation and is independent of an external electrical power source.

Abstract: A fiber grating temperature sensor includes a hollow tube, an optical fiber disposed in the hollow tube such that a gap exists between at least a portion of an internal surface of the hollow tube and an exterior surface of the optical fiber. The optical fiber includes at least one Bragg grating. A lubricant is disposed within the hollow tube, between the exterior surface of the fiber and the interior surface of the hollow tube.

Abstract: A method for configuring a sensor of a non-interference stress management system is disclosed. The method may include determining a focal distance between a light transmitting fiber and a transmit lens, the focal distance configured to focus light from the transmit fiber to form a focused transmit beam, the transmit beam targeting a reflective structure. The method may further include positioning the light transmitting fiber and the transmit lens, wherein the light transmitting fiber and the transmit lens are separated by a transmit gap based on the focal distance and positioning a light receptive fiber and a receive lens to receive a focused reflected beam from the reflective structure, wherein the light receptive fiber is separated from the receive lens by a receive gap based on the focal distance.

Abstract: High precision phosphor temperature sensors are disclosed. The sensors include a light source that emits an excitation light through one or more optical fibers to one or more phosphors that produce fluorescent emission(s) when engaged by the excitation light. The fluorescent emission(s) is transmitted optically from the phosphor(s) directly to a detector or an optical diffraction grating before the light is received at a detector. The detector is linked to a controller, which measures the lifetime(s) of the fluorescent emission(s) and calculates the temperature at the phosphor(s) from said lifetime(s).

Abstract: A phosphor thermometer is disclosed. The phosphor thermometer may comprise a light source configured to emit an excitation light, and an input waveguide configured to transmit at least a portion of the excitation light from the light source to a temperature sensing end. A phosphor may be located at the temperature sensing end and it may be configured to emit a fluorescence signal upon absorption of at least a portion of the excitation light transmitted by the input waveguide. The phosphor thermometer may further comprise an output waveguide configured to transmit at least a portion of the fluorescence signal from the phosphor to a detector. The detector may determine a fluorescence decay constant from the time dependent decay of the fluorescence signal, and the fluorescence decay constant may be correlated with a temperature.

Abstract: A gas turbine engine includes a compressor section, a combustor section and a turbine section mounted relative to an engine static structure. A module includes instrumentation that is mounted to the engine static structure. The module includes an energy harvesting power source that is configured to provide electricity to the instrumentation during engine operation and is independent of an external electrical power source.

Abstract: A station probe employed in a gas turbine engine includes a rake portion having a plurality of sensors for sensing conditions in the gas turbine engine. An environmental container attached to the rake portion includes signal conditioning circuitry that locally analyzes sensor signals received from the plurality of sensors to generate measured values, and a communication module for communicating the measured values to a control room.

Abstract: A high precision phosphor temperature sensor is disclosed. The sensor includes a light source that emits an excitation light through a first optical fiber to a Y-coupler or splitter that connects the first optical fiber to a second optical fiber and a third optical fiber. The second optical fiber connects the Y-coupler to a detector and the third optical fiber connects the Y-coupler to a sensing end of the third optical fiber that is coated with a phosphor that produces a fluorescent emission when engaged by excitation light generated by the light source. The third optical fiber then transmits fluorescent emissions from the phosphor through the Y-coupler whereby at least some of the fluorescent emission passes through the second optical fiber to the detector. The lifetime of the fluorescent emission can be measured and the temperature at the phosphor can be calculated from said lifetime.

Abstract: A method for determining axial location of rotor blades is provided. The method may monitor an output signal of a sensor configured to detect the proximity of the rotor blades, wherein at least one of the rotor blades being marked with a position marker that is configured to cause a recognizable inconsistency in the output signal only when the rotor blades rotate at a known default axial position. The method may further determine the axial displacement of the rotor blades if the inconsistency is not detected in the output signal for at least one full revolution of the rotor blades.

Abstract: A method for determining axial location of rotor blades is provided. The method may monitor an output signal of a sensor configured to detect the proximity of the rotor blades, wherein at least one of the rotor blades being marked with a position marker that is configured to cause a recognizable inconsistency in the output signal only when the rotor blades rotate at a known default axial position. The method may further determine the axial displacement of the rotor blades if the inconsistency is not detected in the output signal for at least one full revolution of the rotor blades.

Abstract: A station probe employed in a gas turbine engine includes a rake portion having a plurality of sensors for sensing conditions in the gas turbine engine. An environmental container attached to the rake portion includes signal conditioning circuitry that locally analyzes sensor signals received from the plurality of sensors to generate measured values, and a communication module for communicating the measured values to a control room.

Abstract: A self-exciting optical strain sensor (20) includes dual parallel bridges (22,24) having parallel facing surfaces (32,34). Light energy (38) entering a Fabry-Perot cavity (36) formed by this surfaces (32,34) induces a periodic buildup and release of energy in the cavity (36) which is directly related to the natural resonant frequency of the bridges (22,24). Analysis of the intensity of light emitted (50) from the cavity (36) determines the bridge natural frequency.

Abstract: A self-exciting optical strain sensor (20) includes dual parallel bridges (22,24) having parallel facing surfaces (32,34). Light energy (38) entering a Fabry-Perot cavity (36) formed by this surfaces (32,34) induces a periodic buildup and release of energy in the cavity (36) which is directly related to the natural resonant frequency of the bridges (22,24). Analysis of the intensity of light emitted (50) from the cavity (36) determines the bridge natural frequency.