Abstract: An engine inlet for efficient operation at both design Mach number and off-design Mach numbers has a variable geometry caret inlet having an initial compression ramp and a principal compression ramp extending aft from and rotatably attached to the initial compression ramp at a forward hinge line. The principal compression ramp is rotatable from a low Mach position to a design Mach position. A diffuser ramp is engaged by the principal compression ramp at an interface. The diffuser ramp is rotatably mounted at an aft hinge line to a diffuser. The diffuser ramp is rotatable oppositely to the principal compression ramp to maintain contact at the interface. An actuation mechanism has a forward cam drive assembly configured to rotate the principal compression ramp about the forward hinge line. An aft cam drive assembly is configured to rotate the diffuser ramp about the aft hinge line. A motor assembly has at least one motor to drive the forward cam drive assembly and the aft cam drive assembly.

Abstract: An engine inlet for efficient operation at both design Mach number and off-design Mach numbers has a variable geometry caret inlet having an initial compression ramp and a principal compression ramp extending aft from and rotatably attached to the initial compression ramp at a forward hinge line. The principal compression ramp is rotatable from a low Mach position to a design Mach position. A diffuser ramp is engaged by the principal compression ramp at an interface. The diffuser ramp is rotatably mounted at an aft hinge line to a diffuser. The diffuser ramp is rotatable oppositely to the principal compression ramp to maintain contact at the interface. An actuation mechanism has a forward cam drive assembly configured to rotate the principal compression ramp about the forward hinge line. An aft cam drive assembly is configured to rotate the diffuser ramp about the aft hinge line. A motor assembly has at least one motor to drive the forward cam drive assembly and the aft cam drive assembly.

Abstract: An inlet diffuser for a jet engine and methods for mixing boundary layers of air in compact inlet diffusers with high offset and high aspect ratio apertures are disclosed. The inlet diffuser includes an inlet diffuser body that includes elongate structures that are configured to allow a first portion of boundary layer air located between the elongate structures to flow within a channel, restrict the first portion of boundary layer air from flowing across either elongate structure, and allow a second portion of boundary layer air located outboard of the elongate structures to flow across the elongate structures and into a region of internal volume inward of the channel, wherein the second portion of boundary layer air is pushed away from the internal surface of the diffuser body by the elongate structures as the second portion of boundary layer air flows across the elongate structures in an inboard direction.

Abstract: An inlet diffuser for a jet engine and methods for mixing boundary layers of air in compact inlet diffusers with high offset and high aspect ratio apertures are disclosed. The inlet diffuser includes an inlet diffuser body that includes elongate structures that are configured to allow a first portion of boundary layer air located between the elongate structures to flow within a channel, restrict the first portion of boundary layer air from flowing across either elongate structure, and allow a second portion of boundary layer air located outboard of the elongate structures to flow across the elongate structures and into a region of internal volume inward of the channel, wherein the second portion of boundary layer air is pushed away from the internal surface of the diffuser body by the elongate structures as the second portion of boundary layer air flows across the elongate structures in an inboard direction.

Abstract: An engine inlet for efficient operation at both design Mach number and off-design Mach numbers with an inlet having a caret configuration with rotatably extending effective leading edges on the inlet from a retracted position aligned with a nominal Mach number shock wave to an extended position aligned with an off-design Mach number shock wave.

Abstract: An engine inlet for efficient operation at both design Mach number and off-design Mach numbers has a fixed compression surface and a leading edge that is variably extendible over the fixed compression surface to simultaneously vary capture area, compression and shock wave position.

Abstract: An engine inlet for efficient operation in both subsonic and supersonic flight wherein the inlet has a caret configuration is rotatable about an off-body axis for compression ramp angle and capture area variation and a diffuser is engaged to the inlet in a scrubbing relationship to maintain a seal upon rotation of the inlet.

Abstract: An airflow diverter system for an aircraft may include an external aircraft surface upstream from an engine inlet and a passage having an upstream opening adjacent the engine inlet. The passage may be configured to channel boundary airflow from the external aircraft surface away from the engine inlet. The diverter system may include an occlusion device configured to selectively open and close the opening to the passage.

Abstract: An airflow diverter system for an aircraft may include an external aircraft surface upstream from an engine inlet and a passage having an upstream opening adjacent the engine inlet. The passage may be configured to channel boundary airflow from the external aircraft surface away from the engine inlet. The diverter system may include an occlusion device configured to selectively open and close the opening to the passage.

Abstract: An engine inlet for efficient operation at both design Mach number and off-design Mach numbers with an inlet having a caret configuration with rotatably extending effective leading edges on the inlet from a retracted position aligned with a nominal Mach number shock wave to an extended position aligned with an off-design Mach number shock wave.

Abstract: An engine inlet for efficient operation at both design Mach number and off-design Mach numbers has a fixed compression surface and a leading edge that is variably extendible over the fixed compression surface to simultaneously vary capture area, compression and shock wave position.

Abstract: An engine inlet for efficient operation in both subsonic and supersonic flight wherein the inlet has a caret configuration is rotatable about an off-body axis for compression ramp angle and capture area variation and a diffuser is engaged to the inlet in a scrubbing relationship to maintain a seal upon rotation of the inlet.

Abstract: The present disclosure is generally directed to a system, aircraft and a method of operation of an aircraft engine including an intake portion and an exhaust portion, an engine inlet, oriented in a forward direction to the intake portion, the engine inlet defined by a peripheral cowling that directs airflow to the intake portion of the aircraft engine, and a spiral cone positioned proximate the engine inlet, the spiral cone including a variable compression surface area that directs airflow immediately in front of the engine inlet.