Abstract: A gas turbine engine includes a rotatably driven engine component including a shaft coupling. The shaft coupling defines a first axial centerline and includes an inner surface. The inner surface includes a plurality of internal splines extending radially inwardly from the inner surface with respect to the first axial centerline. The engine further includes a driving member having a driving end portion and defining a second axial centerline. The driving end portion includes an outer surface and a plurality of external splines extending radially outwardly from the outer surface with respect to the second axial centerline. The plurality of external splines is drivingly engaged with the plurality of internal splines. The plurality of internal splines or the plurality of external splines comprises bowed splines.

Abstract: Unwinding systems and methods are provided for unwinding a fiber from a bobbin. The unwinding system can include an axle defining a first axis extending an axial direction, a bobbin rotatably mounted around the axle, a pulley positioned to receive the fiber from the bobbin, wherein the pulley is rotatable around a second axis, and a sensor positioned between the bobbin and the pulley. The bobbin is moveable along the axial direction, and wherein the fiber extends tangentially from a surface of the bobbin.

Abstract: Unwinding systems and methods are provided for unwinding a fiber from a bobbin. The unwinding system can include an axle defining a first axis extending an axial direction, a bobbin rotatably mounted around the axle, a pulley positioned to receive the fiber from the bobbin, wherein the pulley is rotatable around a second axis, and a sensor positioned between the bobbin and the pulley. The bobbin is moveable along the axial direction, and wherein the fiber extends tangentially from a surface of the bobbin.

Abstract: Methods for coating a fiber are provided. The method can include unwinding a silicon carbide-containing fibrous material from a bobbin rotatably mounted around an axle and forming a boron nitride coating onto the silicon carbide-containing fibrous material. The bobbin is moved along the axial direction such that the silicon carbide-containing fibrous material defines an unwind angle with the axial direction, with the unwind angle being maintained between about 80° to about 100°.

Abstract: The damper system includes a ceramic composite shroud in part defining the hot gas path of a turbine and a spring-biased piston and damper block which bears against the backside surface of the shroud to tune the vibratory response of the shroud relative to pressure pulses of the hot gas path in a manner to avoid near or resonant frequency response. The damper block has projections specifically located to bear against the shroud to dampen the frequency response of the shroud and provide a thermal insulating layer between the shroud and the damper block.