Abstract: An aircraft propulsion system includes a propulsive fan assembly configured for assembly into an aircraft structure, the propulsive fan assembly that includes a fan rotatable about a fan axis, an inlet duct assembly disposed within the aircraft fuselage, the inlet duct assembly that includes an upper inlet duct with an upper inlet opening and a lower inlet duct with a lower inlet opening. The upper inlet duct and the lower inlet duct merge into a common inlet duct forward of the propulsive fan assembly, and an outlet duct is disposed aft of the propulsive fan assembly.

Abstract: An aircraft propulsion system includes a propulsive fan assembly configured for assembly into an aircraft structure, the propulsive fan assembly that includes a fan rotatable about a fan axis, an inlet duct assembly disposed within the aircraft fuselage, the inlet duct assembly that includes an upper inlet duct with an upper inlet opening and a lower inlet duct with a lower inlet opening. The upper inlet duct and the lower inlet duct merge into a common inlet duct forward of the propulsive fan assembly, and an outlet duct is disposed aft of the propulsive fan assembly.

Abstract: A diffuser may comprise an inlet and an outlet. The inlet may comprise an arcuate shape. The outlet may comprise an annular shape. The diffuser may transition from the arcuate shape at the inlet to the annular shape at the outlet. The diffuser may comprise a radially inner wall and a radially outer wall disposed opposite the radially inner wall. The radially inner wall and the radially outer wall may partially define a duct.

Abstract: An aircraft is provided and includes fuselage having a nose, a main section aft of the nose and a tail aft of the main section, an engine nacelle partially embedded in the tail and including a boundary layer ingestion (BLI) propulsor with an inlet directly adjacent to the fuselage and a nozzle element disposed upstream from the inlet and configured to accelerate boundary flows flowing toward the interior side of the engine nacelle.

Abstract: A diffuser may comprise an inlet and an outlet. The inlet may comprise an arcuate shape. The outlet may comprise an annular shape. The diffuser may transition from the arcuate shape at the inlet to the annular shape at the outlet. The diffuser may comprise a radially inner wall and a radially outer wall disposed opposite the radially inner wall. The radially inner wall and the radially outer wall may partially define a duct.

Abstract: An aircraft is provided and includes fuselage having a nose, a main section aft of the nose and a tail aft of the main section, an engine nacelle partially embedded in the tail and including a boundary layer ingestion (BLI) propulsor with an inlet directly adjacent to the fuselage and a nozzle element disposed upstream from the inlet and configured to accelerate boundary flows flowing toward the interior side of the engine nacelle.

Abstract: Embodiments are directed to obtaining a specification comprising at least one requirement associated with a heating, ventilation, and air-conditioning (HVAC) system, and based on the specification, configuring a control system to control a movement of fluid back and forth across at least one regenerator device of the HVAC system and a mixing of the fluid with ambient air.

Abstract: The disclosed turbine engine includes a fan nacelle surrounding a fan and including an inlet arranged upstream from the fan. The inlet includes an inlet surface having a boundary layer flow. A flow control actuator is in fluid communication with the inlet surface. A boundary layer sensing device is associated with the inlet surface for detecting a boundary layer condition at the inlet surface. A controller is in communication with the flow control actuator and the boundary layer sensing device. The controller is programmed to command the flow control actuator in response to the boundary layer sensing device detecting an undesired boundary layer condition. In this manner, the flow control actuator generates a desired boundary layer condition.

Abstract: A turbofan engine includes a fan driven by a low pressure turbine through a gear reduction. The gear reduction has a gear ratio of greater than or equal to about 2.4. The low pressure turbine has an expansion ratio greater than or equal to about 5. The fan has a bypass ratio greater than or equal to about 8. In other features, a turbofan engine includes a variable geometry fan exit guide vane (FEGV) system having a multiple of circumferentially spaced radially extending fan exit guide vanes. Rotation of the fan exit guide vanes between a nominal position and a rotated position selectively changes a fan bypass flow path to permit efficient operation at various flight conditions.

Abstract: A turbofan engine includes a fan variable area nozzle axially movable relative to the fan nacelle to vary a fan nozzle exit area and adjust a pressure ratio of the fan bypass airflow during engine operation.

Abstract: A turbofan engine includes a fan variable area nozzle axially movable relative to the fan nacelle to vary a fan nozzle exit area and adjust a pressure ratio of the fan bypass airflow during engine operation.

Abstract: A turbofan engine includes a variable geometry fan exit guide vane (FEGV) system having a multiple of circumferentially spaced radially extending fan exit guide vanes. Rotation of the fan exit guide vanes between a nominal position and a rotated position selectively changes a fan bypass flow path to permit efficient operation at various flight conditions.

Abstract: A turbofan engine includes a fan variable area nozzle axially movable relative to the fan nacelle to vary a fan nozzle exit area and adjust a pressure ratio of the fan bypass airflow during engine operation.

Abstract: A turbofan engine includes a geared architecture and a fan variable area nozzle axially movable relative to a fan nacelle to vary a fan nozzle exit area and adjust a pressure ratio of the fan bypass airflow during engine operation.

Abstract: A turbofan engine includes a fan variable area nozzle axially movable relative to the fan nacelle to vary a fan nozzle exit area and adjust a pressure ratio of the fan bypass airflow during engine operation.

Abstract: A turbofan engine includes a fan driven by a low pressure turbine through a gear reduction. The gear reduction has a gear ratio of greater than or equal to about 2.4. The low pressure turbine has an expansion ratio greater than or equal to about 5. The fan has a bypass ratio greater than or equal to about 8. In other features, a turbofan engine includes a variable geometry fan exit guide vane (FEGV) system having a multiple of circumferentially spaced radially extending fan exit guide vanes. Rotation of the fan exit guide vanes between a nominal position and a rotated position selectively changes a fan bypass flow path to permit efficient operation at various flight conditions.

Abstract: A rotor hub fairing system includes an upper hub fairing, a lower hub fairing and a shaft fairing therebetween. The rotor hub fairing system reduces the total drag on a dual, counter-rotating, coaxial rotor system. Other aerodynamic structures may be mounted to the shaft fairing, hub fairings and airframe to facilitate flow around the upper and lower hub fairings to reduce flow separation and drag.

Abstract: A turbofan engine includes a variable geometry fan exit guide vane (FEGV) system having a multiple of circumferentially spaced radially extending fan exit guide vanes. Rotation of the fan exit guide vanes between a nominal position and a rotated position selectively changes a fan bypass flow path to permit efficient operation at various flight conditions.

Abstract: The disclosed turbine engine includes a fan nacelle surrounding a fan and including an inlet arranged upstream from the fan. The inlet includes an inlet surface having a boundary layer flow. A flow control actuator is in fluid communication with the inlet surface. A boundary layer sensing device is associated with the inlet surface for detecting a boundary layer condition at the inlet surface. A controller is in communication with the flow control actuator and the boundary layer sensing device. The controller is programmed to command the flow control actuator in response to the boundary layer sensing device detecting an undesired boundary layer condition. In this manner, the flow control actuator generates a desired boundary layer condition.

Abstract: A vane has an airfoil shell and a spar within the shell. The vane has an outboard shroud at an outboard end of the shell and an inboard platform at an inboard end of the shell. The spar has a first chamber essentially along the suction side and a second chamber along the pressure side opposite the first chamber.