Abstract: Embodiments of thermal-acoustic sections for an aircraft for reducing noise along an acoustic path produced from an acoustic source are provided herein. The thermal-acoustic section comprises a first porous layer having a first characteristic acoustic impedance. A second porous layer is disposed adjacent to the first porous layer and has a second characteristic acoustic impedance that is greater than the first characteristic acoustic impedance. The thermal-acoustic section is configured to be positioned along the acoustic path such that at least a portion of the noise from the acoustic source is directed through the first porous layer to the second porous layer to promote absorption of the noise.

Abstract: Embodiments of thermal-acoustic sections for an aircraft for reducing noise along an acoustic path produced from an acoustic source are provided herein. The thermal-acoustic section comprises a first porous layer having a first characteristic acoustic impedance. A second porous layer is disposed adjacent to the first porous layer and has a second characteristic acoustic impedance that is greater than the first characteristic acoustic impedance. The thermal-acoustic section is configured to be positioned along the acoustic path such that at least a portion of the noise from the acoustic source is directed through the first porous layer to the second porous layer to promote absorption of the noise.

Abstract: Embodiments of reinforced composite structures for aircrafts and methods for making such reinforced composite structures are provided herein. A reinforced composite structure for an aircraft comprises a fiber reinforced composite stringer. The fiber reinforced composite stringer comprises a beam body portion and a runout portion that extends from the beam body portion in a first direction. The beam body and runout portions are defined by projection of a variable I-shaped cross-section in the first direction along at least a portion of an entire combined length of the beam body and runout portions. The variable I-shaped cross-section has a cap section, a foot section, and a web section that extends between the cap and foot sections. The variable I-shaped cross-section is configured such that a height of the web section tapers in the first direction along at least a portion of an entire length of the runout portion.

Abstract: Embodiments of reinforced composite structures for aircrafts and methods for making such reinforced composite structures are provided herein. A reinforced composite structure for an aircraft comprises a fiber reinforced composite stringer. The fiber reinforced composite stringer comprises a beam body portion and a runout portion that extends from the beam body portion in a first direction. The beam body and runout portions are defined by projection of a variable I-shaped cross-section in the first direction along at least a portion of an entire combined length of the beam body and runout portions. The variable I-shaped cross-section has a cap section, a foot section, and a web section that extends between the cap and foot sections. The variable I-shaped cross-section is configured such that a height of the web section tapers in the first direction along at least a portion of an entire length of the runout portion.

Abstract: Embodiments of thermal-acoustic sections for an aircraft for reducing noise along an acoustic path produced from an acoustic source are provided herein. The thermal-acoustic section comprises a first porous layer having a first characteristic acoustic impedance. A second porous layer is disposed adjacent to the first porous layer and has a second characteristic acoustic impedance that is greater than the first characteristic acoustic impedance. The thermal-acoustic section is configured to be positioned along the acoustic path such that at least a portion of the noise from the acoustic source is directed through the first porous layer to the second porous layer to promote absorption of the noise.

Abstract: The present invention relates to an integrally bladed rotor for use in a gas turbine engine. The integrally bladed rotor comprises a plurality of pairs of airfoil blades. Each pair of blades has a spar which extends from a first tip of a first one of the airfoil blades in the pair to a second tip of a second one of the airfoil blades in the pair. The rotor further comprises an outer shroud integrally joined to the first and second tips in each pair of airfoil blades and an inner diameter hub.

Abstract: The present invention relates to an integrally bladed rotor for use in a gas turbine engine. The integrally bladed rotor comprises a plurality of pairs of airfoil blades. Each pair of blades has a spar which extends from a first tip of a first one of the airfoil blades in the pair to a second tip of a second one of the airfoil blades in the pair. The rotor further comprises an outer shroud integrally joined to the first and second tips in each pair of airfoil blades and an inner diameter hub.

Abstract: The present invention relates to an integrally bladed rotor for use in a gas turbine engine. The integrally bladed rotor comprises a plurality of pairs of airfoil blades. Each pair of blades has a spar which extends from a first tip of a first one of the airfoil blades in the pair to a second tip of a second one of the airfoil blades in the pair. The rotor further comprises an outer shroud integrally joined to the first and second tips in each pair of airfoil blades and an inner diameter hub.