Abstract: The gas turbine compressor for an aircraft gas turbine engine includes a compressor rotor having a plurality of compressor blades circumferentially distributed around a hub. Each of the compressor blades has an airfoil extending radially outward from the hub to a blade tip. A circumferential row of the compressor blades includes two or more different blade types, at least one modified blade of the two or more different blade types having means for generating different shock patterns between adjacent ones of the two or more different blade types when the gas turbine compressor operates in supersonic flow regimes. The means for generating different shock patterns on the modified blade aerodynamically mistune the two or more different blade types.

Abstract: A system (302) includes a battery powered wireless alert device (3041, . . . , 3041, . . . , 304N) and a battery powered wireless alert device monitor (3061, . . . , 3061, . . . , 306N). The battery powered wireless alert device includes electronic circuitry (2021), a transmitter (2041) configured to transmit a signal at a predetermined first rate to an alarm device (110), a logic circuit (4021) configured to generate an output signal at a predetermined second rate, wherein the first rate is lower than the second rate, and a power source (2061) configured to supply power to at least the electronic circuitry and the logic circuit.

Abstract: A system (302) includes a battery powered wireless alert device (3041, . . . , 3041, . . . , 304N) and a battery powered wireless alert device monitor (3061, . . . , 3061, . . . , 306N). The battery powered wireless alert device includes electronic circuitry (2021), a transmitter (2041) configured to transmit a signal at a predetermined first rate to an alarm device (110), a logic circuit (4021) configured to generate an output signal at a predetermined second rate, wherein the first rate is lower than the second rate, and a power source (2061) configured to supply power to at least the electronic circuitry and the logic circuit.

Abstract: The gas turbine compressor for an aircraft gas turbine engine includes a compressor rotor having a plurality of compressor blades circumferentially distributed around a hub. Each of the compressor blades has an airfoil extending radially outward from the hub to a blade tip. A circumferential row of the compressor blades includes two or more different blade types, at least one modified blade of the two or more different blade types having means for generating different shock patterns between adjacent ones of the two or more different blade types when the gas turbine compressor operates in supersonic flow regimes. The means for generating different shock patterns on the modified blade aerodynamically mistune the two or more different blade types.

Abstract: A compressor rotor for a gas turbine engine is described which includes sets of blades having different airfoil thickness distributions, each including a frequency modifier forming a thickness differential relative to a baseline blade thickness. The frequency modifiers provide different natural vibration frequencies for each of the blades, and facilitate modifying natural vibration frequency separation between adjacent blades of the compressor rotor.

Abstract: A compressor rotor, such as a fan, for a gas turbine engine is described which includes alternating at least first and second blade types. The leading edge of the second blade types includes a leading edge tip cutback extending to the blade tip thereof. The leading edge tip cutback of the second blade type defines a chord length at the blade tip of the second blade types that is less than that of the first blades types. The first and second blade types generate different shock patterns when the fan or compressor rotor operates in supersonic flow regimes.

Abstract: A compressor rotor for a gas turbine engine is described which includes sets of blades having different airfoil thickness distributions, each including a frequency modifier forming a thickness differential relative to a baseline blade thickness. The frequency modifiers provide different natural vibration frequencies for each of the blades, and facilitate modifying natural vibration frequency separation between adjacent blades of the compressor rotor.

Abstract: A compressor rotor for a gas turbine engine is described which includes sets of blades having different airfoil thickness distributions, each including a frequency modifier forming a thickness differential relative to a baseline blade thickness. The frequency modifiers provide different natural vibration frequencies for each of the blades, and facilitate modifying natural vibration frequency separation between adjacent blades of the compressor rotor.

Abstract: A compressor rotor, such as a fan, for a gas turbine engine is described which includes alternating at least first and second blade types. The leading edge of the second blade types includes a leading edge tip cutback extending to the blade tip thereof. The leading edge tip cutback of the second blade type defines a chord length at the blade tip of the second blade types that is less than that of the first blades types. The first and second blade types generate different shock patterns when the fan or compressor rotor operates in supersonic flow regimes.

Abstract: A compressor rotor for a gas turbine engine is described which includes sets of blades having different airfoil thickness distributions, each including a frequency modifier forming a thickness differential relative to a baseline blade thickness. The frequency modifiers provide different natural vibration frequencies for each of the blades, and facilitate modifying natural vibration frequency separation between adjacent blades of the compressor rotor.

Abstract: A multiplexer selects an input signal from one of plural sensors. An A/D converter converts the selected input signal to a digital input value. A processor then determines, based on the digital input value, an output resistance to which the resistance of the selected sensor is to be translated. Finally, the processor controls a digital potentiometer corresponding to the selected sensor to the determined output resistance. In one embodiment, a conditioning circuit adjusts the gain of the input signal according to calibration data, effectively performing at least a part of the translation in the analog domain.

Abstract: A multiplexer selects an input signal from one of plural sensors. An A/D converter converts the selected input signal to a digital input value. A processor then determines, based on the digital input value, an output resistance to which the resistance of the selected sensor is to be translated. Finally, the processor controls a digital potentiometer corresponding to the selected sensor to the determined output resistance. In one embodiment, a conditioning circuit adjusts the gain of the input signal according to calibration data, effectively performing at least a part of the translation in the analog domain.

Abstract: A hand-held calibrator unit plugs into the same connector used for attaching a measurement probe to a measuring instrument; the instrument recognizes the presence of the calibrator and automatically calibrates itself using a reference electrical parameter provided by the calibrator and data stored in the calibrator.