Abstract: A system is provided for testing a component. This system includes a support structure, an excitation system and a sensor system. The support structure is configured to support the component. The excitation system includes a plurality of excitation devices arranged in an array. The plurality of excitation devices at least include a first excitation device, a second excitation device and a third excitation device. The excitation system is configured to respectively control each of the plurality of excitation devices to excite a vibratory response in the component. The sensor system is configured to output data indicative of the vibratory response.

Abstract: A turbomachine airfoil element has an airfoil. The airfoil has an inboard end, an outboard end, a leading edge, a trailing edge, a pressure side, and a suction side. A span between the inboard and an outboard end is 1.4-1.6 inch. A chord length at 50% span is 0.9-1.4 inch. The element is remanufactured by providing first, second, third, fourth, and fifth mode resonance frequencies respectively of 2591.5±10% Hz, 4675.2±10% Hz, 7892.9±10% Hz, 10098.2±10% Hz, and 14808.2±10% Hz.

Abstract: A system is provided for testing a component. This system includes a support structure, an excitation system and a sensor system. The support structure is configured to support the component. The excitation system includes a plurality of excitation devices arranged in an array. The plurality of excitation devices at least include a first excitation device, a second excitation device and a third excitation device. The excitation system is configured to respectively control each of the plurality of excitation devices to excite a vibratory response in the component. The sensor system is configured to output data indicative of the vibratory response.

Abstract: A system is provided for testing a component. This system includes a support structure, an excitation system and a sensor system. The support structure is configured to support the component. The excitation system includes a plurality of permanent magnets and a plurality of electromagnets. The permanent magnets are arranged in an array and configured for rigid connection to the component. Each of the electromagnets is associated with a respective one of the permanent magnets. The excitation system is configured to respectively control interaction of the electromagnets with the permanent magnets to excite a vibratory response in the component. The sensor system is configured to output data indicative of the vibratory response.

Abstract: A gas turbine engine may include a liftoff carbon seal assembly. Liftoff carbon seal assembly may include a static seal support structure, a magnetic carrier spring assembly coupled to the static seal support structure, a nonferrous metal slab magnetically associated with the magnetic carrier spring assembly and coupled to the static seal support structure. In various embodiments, a combination of the magnetic carrier spring assembly and the nonferrous metal slab create a counter-force using an eddy current to oppose a motion of the magnetic carrier spring assembly.

Abstract: A system is provided for testing a component. This system includes a support structure, an excitation system and a sensor system. The support structure is configured to support the component. The excitation system includes a plurality of permanent magnets and a plurality of electromagnets. The permanent magnets are arranged in an array and configured for rigid connection to the component. Each of the electromagnets is associated with a respective one of the permanent magnets. The excitation system is configured to respectively control interaction of the electromagnets with the permanent magnets to excite a vibratory response in the component. The sensor system is configured to output data indicative of the vibratory response.

Abstract: A gas turbine engine may include a liftoff carbon seal assembly. Liftoff carbon seal assembly may include a static seal support structure, a magnetic carrier spring assembly coupled to the static seal support structure, a nonferrous metal slab magnetically associated with the magnetic carrier spring assembly and coupled to the static seal support structure. In various embodiments, a combination of the magnetic carrier spring assembly and the nonferrous metal slab create a counter-force using an eddy current to oppose a motion of the magnetic carrier spring assembly.

Abstract: A bearing assembly is provided. The bearing assembly may include an inner race configured to couple to a shaft, an outer race disposed around the inner race, a bearing support structure coupled to the outer race, and a housing disposed around the bearing support structure. The housing and the bearing support structure may define a squeeze-film damper annulus configured to receive an aerated damping fluid. The aerated damping fluid may be provided from a fluid pump and an air supply port.

Abstract: A turbomachine airfoil element has an airfoil. The airfoil has an inboard end, an outboard end, a leading edge, a trailing edge, a pressure side, and a suction side. A span between the inboard and an outboard end is 1.4-1.6 inch. A chord length at 50% span is 0.9-1.4 inch. At least three of the following resonance frequencies are present. A first mode resonance frequency is 2591.5±10% Hz. A second mode resonance frequency is 4675.2±10% Hz. A third mode resonance frequency is 7892.9±10% Hz. A fourth mode resonance frequency is 10098.2±10% Hz. A fifth mode resonance frequency is 14808.2±10% Hz.

Abstract: A resonant frequency testing system for airfoils comprises a broach block, a clamp, an acoustic speaker, a laser vibrometer, and a control processor assembly. The broach block has a slot disposed to receive the airfoil in an airfoil location. The clamp has a torque-actuated shutoff, and is disposed to lock the airfoil in the broach block slot under a fixed clamping force. The acoustic sensor is disposed adjacent the airfoil location to emit sonic pulses, and the laser vibrometer is oriented towards the airfoil location to sense vibration signatures of the airfoil when excited by the sonic pulses. The control processor assembly is configured to control the acoustic speaker and laser vibrometer, to decompose the sensed vibration signatures into resonant frequencies of the airfoil, and to store the resonant frequencies in a digital storage database, correlated with a unique ID corresponding to the airfoil.

Abstract: A turbomachine airfoil element has an airfoil. The airfoil has an inboard end, an outboard end, a leading edge, a trailing edge, a pressure side, and a suction side. A span between the inboard and an outboard end is 1.4-1.6 inch. A chord length at 50% span is 0.9-1.4 inch. At least three of the following resonance frequencies are present. A first mode resonance frequency is 2591.5±10% Hz. A second mode resonance frequency is 4675.2±10% Hz. A third mode resonance frequency is 7892.9±10% Hz. A fourth mode resonance frequency is 10098.2±10% Hz. A fifth mode resonance frequency is 14808.2±10% Hz.

Abstract: A resonant frequency testing system for airfoils comprises a broach block, a clamp, an acoustic speaker, a laser vibrometer, and a control processor assembly. The broach block has a slot disposed to receive the airfoil in an airfoil location. The clamp has a torque-actuated shutoff, and is disposed to lock the airfoil in the broach block slot under a fixed clamping force. The acoustic sensor is disposed adjacent the airfoil location to emit sonic pulses, and the laser vibrometer is oriented towards the airfoil location to sense vibration signatures of the airfoil when excited by the sonic pulses.

Abstract: A turbomachine airfoil element has an airfoil. The airfoil has an inboard end, an outboard end, a leading edge, a trailing edge, a pressure side, and a suction side. A span between the inboard and an outboard end is 1.4-1.6 inch. A chord length at 50% span is 0.9-1.4 inch. At least three of the following resonance frequencies are present. A first mode resonance frequency is 2591.5±10% Hz. A second mode resonance frequency is 4675.2±10% Hz. A third mode resonance frequency is 7892.9±10% Hz. A fourth mode resonance frequency is 10098.2±10% Hz. A fifth mode resonance frequency is 14808.2±10% Hz.

Abstract: An integrated excitation and measurement system includes a support member. A single confocal ultrasonic transducer is mounted to the support member. The ultrasonic transducer is configured to produce first and second ultrasonic beams having different frequencies than one another that generate an excitation input at a focal point. First, second and third fiber optic elements are mounted to the support member and aligned with the focal point. The fiber optic elements are configured to sense a three-dimensional excitation response at the focal point.

Abstract: A rig for studying a component has a component support for mounting the component. A speaker applies sound energy to airfoils in the component. A vibrometer studies the effect of the applied sound on the airfoils. At least two of the vibrometer, the component support, and the speaker are rotatable relative to each other. In a separate feature, a vibrometer for studying the effect of sound energy on airfoils in a component is provided with a vision system. The vision system is operable to identify the exact location at which the laser is studying the effect on the airfoil. Methods are also disclosed.

Abstract: A stator for a turbo-machine having a plurality of airfoils extending radially therefrom has a base from which the airfoils depend, and slits disposed in the base, each slit disposed adjacent a pair of airfoils, wherein a first set of adjacent slits and a distance between a second set of adjacent slits varies

Abstract: A rig for studying a component has a component support for mounting the component. A speaker applies sound energy to airfoils in the component. A vibrometer studies the effect of the applied sound on the airfoils. At least two of the vibrometer, the component support, and the speaker are rotatable relative to each other. In a separate feature, a vibrometer for studying the effect of sound energy on airfoils in a component is provided with a vision system. The vision system is operable to identify the exact location at which the laser is studying the effect on the airfoil. Methods are also disclosed.