Abstract: A propulsion system is provided, wherein the propulsion system includes an afterburner assembly. The afterburner assembly including: an exhaust section and a fuel injector assembly that is operable to inject fuel in the exhaust section. The fuel injector assembly includes a plurality of fuel injection members. The plurality of fuel injection members defines a hot zone and a cold zone. The cold zone is positioned to provide a noise insulation barrier for the hot zone.

Abstract: Noise attenuation structures, such as acoustic liners for gas turbine engines, are provided. For example, an acoustic liner comprises a face sheet, a backing sheet spaced apart from the face sheet, and a plurality of cavities defined between the face and backing sheets. The cavities are defined by cavity walls. A plurality of backing sheet walls extends from the backing sheet toward the face sheet. The backing sheet walls extend adjacent the cavity walls, and the backing sheet is movable with respect to the face sheet such that the cavities have a variable depth. Other embodiments of noise attenuation structures also are provided.

Abstract: An apparatus for attenuating sound waves includes a first surface, a second surface opposite the first surface, and at least one opening defined by the second surface. The apparatus also includes a heat exchanger defining a plurality of cooling channels therein and including a plurality of fins. The plurality of cooling channels extend between the first surface and the second surface. The plurality of fins extend from the second surface. The apparatus further includes at least one cavity extending between the first surface and the second surface. The at least one cavity is in flow communication with the at least one opening. The at least one opening and the at least one cavity are configured to attenuate the sound waves. The apparatus also includes at least one passageway extending between the at least one opening and the at least one cavity and positioned between the plurality of cooling channels.

Abstract: An apparatus for attenuating sound waves in a gas turbine engine includes a surface at least partially defining a pathway for airflow and a plurality of fins extending from the surface. The plurality of fins are configured to dissipate heat into the airflow. Each fin of the plurality of fins includes a fin surface. The fin surface is configured to direct the sound waves between the plurality of fins such that the plurality of fins attenuate the sound waves. The plurality of fins are arranged such that spacing between adjacent fins of the plurality of fins facilitates sound attenuation.

Abstract: Noise attenuation structures, such as acoustic liners for gas turbine engines, are provided. For example, an acoustic liner comprises a face sheet, a backing sheet spaced apart from the face sheet, and a plurality of cavities defined between the face and backing sheets. The cavities are defined by cavity walls. A plurality of backing sheet walls extends from the backing sheet toward the face sheet. The backing sheet walls extend adjacent the cavity walls, and the backing sheet is movable with respect to the face sheet such that the cavities have a variable depth. Other embodiments of noise attenuation structures also are provided.

Abstract: An apparatus for attenuating sound waves in a gas turbine engine includes a surface at least partially defining a pathway for airflow and a plurality of fins extending from the surface. The plurality of fins are configured to dissipate heat into the airflow. Each fin of the plurality of fins includes a fin surface. The fin surface is configured to direct the sound waves between the plurality of fins such that the plurality of fins attenuate the sound waves. The plurality of fins are arranged such that spacing between adjacent fins of the plurality of fins facilitates sound attenuation.

Abstract: An apparatus for attenuating sound waves includes a first surface, a second surface opposite the first surface, and at least one opening defined by the second surface. The apparatus also includes a heat exchanger defining a plurality of cooling channels therein and including a plurality of fins. The plurality of cooling channels extend between the first surface and the second surface. The plurality of fins extend from the second surface. The apparatus further includes at least one cavity extending between the first surface and the second surface. The at least one cavity is in flow communication with the at least one opening. The at least one opening and the at least one cavity are configured to attenuate the sound waves. The apparatus also includes at least one passageway extending between the at least one opening and the at least one cavity and positioned between the plurality of cooling channels.

Abstract: An airfoil and method of fabricating an airfoil including a first and a second side coupled at a leading and a trailing edge and extending there between. The airfoil includes a plurality of first chord sections having a first chord length and extending outward from one of the first side or second side at the leading edge and a plurality of second chord sections having a second chord length and extending outward from the one of the first side or the second side at the leading edge. The leading edge including spaced-apart wave-shaped projections defining a waveform. The configuration defining a three-dimensional crenulated airfoil configured to facilitate desensitization of an airfoil unsteady pressure response to at least one impinging upstream generated wake or vortex by decorrelating spatially and temporally and reducing in amplitude an unsteady pressure caused by interaction of the airfoil with the upstream generated wake or vortex.

Abstract: An airfoil and method of fabricating an airfoil including a first and a second side coupled together at a leading and a trailing edge and extending there between. The airfoil includes a plurality of first chord sections having a first chord length and extending outward from one of the first side or second side of the airfoil at the leading edge and a plurality of second chord sections having a second chord length and extending outward from the one of the first side or the second side of the airfoil at the leading edge. The leading edge including spaced-apart wave-shaped projections defining a waveform. The configuration defining a three-dimensional crenulated airfoil configured to facilitate desensitization of an airfoil unsteady pressure response to at least one impinging upstream generated wake or vortex by decorrelating spatially and temporally and reducing in amplitude an unsteady pressure caused by interaction of the airfoil with the upstream generated wake or vortex.