Abstract: A method for reducing tip rub loads in a rotor blade is described having the steps of selecting a location of contact between the rotor blade and a static structure; selecting a location on the blade for incorporating a tip-cutter; selecting a cutter-profile for the tip-cutter; and incorporating the tip-cutter on the selected location on the blade such that tip-cutter is capable of removing a portion of the static structure during a tip rub such that tip rub loads are facilitated to be reduced.

Abstract: An airfoil for use in a rotor assembly is disclosed, the airfoil having a tip-cutter located on a sidewall near a tip portion, wherein the tip-cutter is capable of removing a portion of an abradable material during a tip rub. In another embodiment, an airfoil has a tip-grinder located on the tip portion, wherein the tip-grinder capable of removing a portion of an abradable material during a tip rub. In another embodiment, an airfoil has a tip-rake that facilitates reducing loading induced to said airfoil during tip rubs.

Abstract: A method and apparatus for reducing dynamic loading of a gas turbine engine is provided. The gas turbine engine includes a rotor shaft assembly including a rotor shaft, a bearing assembly, a mounting race, and a support frame, the mounting race including a spherical surface. The method includes supporting the rotor shaft on the gas turbine engine support frame with the bearing assembly, the rotor shaft including a yield portion configured to permit bending of the rotor shaft during an imbalance operation.

Abstract: An airfoil for use in a rotor assembly is disclosed, the airfoil having a tip-cutter located on a sidewall near a tip portion, wherein the tip-cutter is capable of removing a portion of an abradable material during a tip rub. In another embodiment, an airfoil has a tip-grinder located on the tip portion, wherein the tip-grinder capable of removing a portion of an abradable material during a tip rub. In another embodiment, an airfoil has a tip-rake that facilitates reducing loading induced to said airfoil during tip rubs.

Abstract: A method for reducing tip rub loads in a rotor blade is described having the steps of selecting a location of contact between the rotor blade and a static structure; selecting a location on the blade for incorporating a tip-cutter; selecting a cutter-profile for the tip-cutter; and incorporating the tip-cutter on the selected location on the blade such that tip-cutter is capable of removing a portion of the static structure during a tip rub such that tip rub loads are facilitated to be reduced.

Abstract: A method and apparatus for reducing dynamic loading of a gas turbine engine is provided. The gas turbine engine includes a rotor shaft assembly including a rotor shaft, a bearing assembly, a mounting race, and a support frame, the mounting race including a spherical surface. The method includes supporting the rotor shaft on the gas turbine engine support frame with the bearing assembly, the rotor shaft including a yield portion configured to permit bending of the rotor shaft during an imbalance operation.

Abstract: A method of ordering blades in a rotatable machine that includes a plurality of blades that extend radially outwardly from a rotor is provided. The method includes receiving at least one geometric parameter measurement of each blade in a row of blades, determining a maximum difference of at least one of the received geometric parameter measurements between adjacent blades in the row of blades, determining a vector sum of at least one of the received geometric parameter measurements, determining a plurality of moment weight vector sums of the rotor, and determining, using a computer, a sequence map of each blade using the maximum difference of the at least one geometric parameter measurement between adjacent blades in the row of blades, the vector sum of the at least one received geometric parameter measurement, and the plurality of moment weight vector sums.

Abstract: A method of ordering blades in a rotatable machine that includes a plurality of blades that extend radially outwardly from a rotor is provided. The method includes receiving at least one geometric parameter measurement of each blade in a row of blades, determining a maximum difference of at least one of the received geometric parameter measurements between adjacent blades in the row of blades, determining a vector sum of at least one of the received geometric parameter measurements, determining a plurality of moment weight vector sums of the rotor, and determining, using a computer, a sequence map of each blade using the maximum difference of the at least one geometric parameter measurement between adjacent blades in the row of blades, the vector sum of the at least one received geometric parameter measurement, and the plurality of moment weight vector sums.

Abstract: A method, rotor assembly, and apparatus for ordering blades in a rotatable machine is provided. The rotor assembly includes a disk including a plurality of circumferentially-spaced blade root slots defined therein, and a plurality of blades, each blade including a root, a tip, and an airfoil therebetween, each blade positioned within a pre-determined slot based on a blade map, the blade map generated by a computer system configured to receive a geometric parameter measurement of each blade in a row of blades, determine a shape factor for the row of blades using the geometric parameter measurement of each blade, and determine a sequence map of each blade using the shape factor for the row of blades.

Abstract: A system and method are provided for allowing simplified access to the raw vibration data. The signal conditioner, even if mounted on the engine or the engine pylon, digitizes the input signals and can analyze and store a finite amount of raw data. The raw signals are digitized at a high rate of speed, and the digitized values are stored. The stored values can be retrieved after flight. This aircraft vibration processor and recording system allows easy access to the raw vibration waveform, even in configurations where the processor is located on the engine or the engine pylon.

Abstract: The present invention provides a system and method for using the external accelerometer in an aircraft engine configuration as a backup accelerometer, in the event the internally located production accelerometer fails. The sensor location of the external accelerometer has an acceptable sensitivity to fan imbalance, similar to the location of the former alternate accelerometer. The signal from this external accelerometer is duplicated using software in the signal conditioning hardware, creating the second, alternate signal. As an alternative embodiment, the signal may be duplicated by simply teeing or branching the original signal, using hardware rather than software.

Abstract: The present invention provides a system and method for using the external accelerometer in an aircraft engine configuration as a backup accelerometer, in the event the internally located production accelerometer fails. The sensor location of the external accelerometer has an acceptable sensitivity to fan imbalance, similar to the location of the former alternate accelerometer. The signal from this external accelerometer is duplicated using software in the signal conditioning hardware, creating the second, alternate signal. As an alternative embodiment, the signal may be duplicated by simply teeing or branching the original signal, using hardware rather than software.

Abstract: A system and method are provided for allowing simplified access to the raw vibration data. The signal conditioner, even if mounted on the engine or the engine pylon, digitizes the input signals and can analyze and store a finite amount of raw data. The raw signals are digitized at a high rate of speed, and the digitized values are stored. The stored values can be retrieved after flight. This aircraft vibration processor and recording system allows easy access to the raw vibration waveform, even in configurations where the processor is located on the engine or the engine pylon.

Abstract: A flexible adaptor mounts an aircraft gas turbine engine to a test stand. The adaptor includes an upper frame configured for mounting on the test stand, and a lower frame spaced from the upper frame and configured for supporting the engine. A spring flexibly joins the lower frame to the upper frame to simulate the flexibility of an aircraft wing which supports the engine during operation.

Abstract: A sealed squeeze film damper having double annular wall sealed plenums at the open ends of the damper which seal the damper and prevent air from being sucked into a sealed film damper thereby preventing degradation of damper performance due to air entrainment in the damper fluid. This significantly improves the damper performance by preventing air entrainment in the damper fluid.