An aircraft wing with a system for optimizing boundary layer control. The aircraft wing includes an enclosing structure, an inner cavity defined within the aircraft wing, and at least one bellows assembly disposed in the inner cavity. The bellows assembly is spaced apart from the inner surfaces of the enclosing structure so as to define a void between the bellows assembly and the inner surfaces. Boundary control inlets are defined in the enclosing structure and a wake-immersed propulsion exhaust duct disposed proximate the trailing edge of the wing.

An aircraft may have one or more electrically powered thrust-generating engines and a combustion engine forming part of a power generator system for powering the electric engine and/or recharging a battery system that powers the electric engine. An exhaust pipe leads via an interior space within the aircraft from the exhaust of the combustion engine, or other source of hot gases, to an exhaust outlet. The direction of the exhaust pipe at the outlet is transverse to the longitudinal axis of the aircraft. A fairing immediately upstream of the outlet has a trailing edge, for example with a sawtooth profile, which creates turbulence and/or chaotic airflow over and downstream of the outlet, and thus mixes the freestream air and the hot gases from inside the aircraft more efficiently.

An aircraft may have one or more electrically powered thrust-generating engines and a combustion engine forming part of a power generator system for powering the electric engine and/or recharging a battery system that powers the electric engine. An exhaust pipe leads via an interior space within the aircraft from the exhaust of the combustion engine, or other source of hot gases, to an exhaust outlet. The direction of the exhaust pipe at the outlet is transverse to the longitudinal axis of the aircraft. A fairing immediately upstream of the outlet has a trailing edge, for example with a sawtooth profile, which creates turbulence and/or chaotic airflow over and downstream of the outlet, and thus mixes the freestream air and the hot gases from inside the aircraft more efficiently.

An aircraft and a control system for the aircraft includes a tilt-wing defining an inlet configured to receive air and an outlet in fluid communication with the inlet such that the outlet is configured to expel the air. The control system includes a high-lift device coupled to at least one of a leading edge, and a trailing edge of the tilt-wing. The high-lift device is movable relative to the tilt-wing. The control system includes a compressor in fluid communication with the inlet and the outlet. The compressor is configured to increase pressure of the air that is expelled out of the outlet. The outlet directs the pressurized air toward at least one of the high-lift device and a center section of the tilt-wing to maintain attachment of airflow across the tilt-wing. A method of operating the control system of the aircraft occurs to maintain attachment of airflow across the tilt-wing.

Sound absorbers and airframe components comprising such sound absorbers are disclosed. In one embodiment, an airframe component comprises an aerodynamic surface (48) and a sound absorber (38). The sound absorber (38) comprises a perforated panel (40) having a front side exposed to an ambient environment outside of the airframe component and an opposite back side. The panel (40) comprises perforations extending through a thickness of the panel for permitting passage of sound waves therethrough. The sound absorber (38) also comprises a boundary surface spaced apart from the perforated panel. The boundary surface and the back side of the perforated panel (40) at least partially define a cavity in the airframe component for attenuating some of the sound waves entering the cavity via the perforations in the perforated panel (40).

Sound absorbers and airframe components comprising such sound absorbers are disclosed. In one embodiment, an airframe component comprises an aerodynamic surface (48) and a sound absorber (38). The sound absorber (38) comprises a perforated panel (40) having a front side exposed to an ambient environment outside of the airframe component and an opposite back side. The panel (40) comprises perforations extending through a thickness of the panel for permitting passage of sound waves therethrough. The sound absorber (38) also comprises a boundary surface spaced apart from the perforated panel. The boundary surface and the back side of the perforated panel (40) at least partially define a cavity in the airframe component for attenuating some of the sound waves entering the cavity via the perforations in the perforated panel (40).

A lift-changing mechanism is configured to change generated by a wing of an aircraft and includes a slit and an opening and closing member. The slit extends in a wingspan direction inside the wing and forms openings on the lower surface of the wing and on the upper surface of the wing respectively. A part of airflow below the lower surface is allowed to flow toward the upper surface through the slit. The opening and closing member is configured to open and close the slit. When the opening and closing member opens the slit, lift generated on the wing is decreased compared with when the slit is closed.

In order to further benefit from the principle of boundary layer ingestion by engines of an aircraft assembly, the rear portion of the fuselage of this aircraft assembly includes a front portion which splits up into at least two distinct rear portions, spaced apart from each other, and each integrating the rotary ring of the receiver of one of the engines.

A spoiler assembly is provided that is engageable to a UAV that defines a body, an outer surface and an inner surface. The spoiler assembly comprises a spoiler, translatably connected to the UAV inner surface adjacent a first portion of the spoiler aperture. The spoiler defines an upper surface and an outer surface, the upper surface being substantially the same size and shape as the spoiler aperture. A spoiler shroud is connected to the UAV inner surface and extends within the UAV body about at least a portion of the spoiler aperture. A spoiler activating mechanism is secured to the UAV inner surface and connected the spoiler lower surface. The mechanism is operative to translate the spoiler between a first position wherein the spoiler upper surface is substantially flush with the UAV outer surface, and second a position, wherein the spoiler upper surface is disposed substantially within the UAV body.

A spoiler assembly is provided that is engageable to a UAV that defines a body, an outer surface and an inner surface. The spoiler assembly comprises a spoiler, translatably connected to the UAV inner surface adjacent a first portion of the spoiler aperture. The spoiler defines an upper surface and an outer surface, the upper surface being substantially the same size and shape as the spoiler aperture. A spoiler shroud is connected to the UAV inner surface and extends within the UAV body about at least a portion of the spoiler aperture. A spoiler activating mechanism is secured to the UAV inner surface and connected the spoiler lower surface. The mechanism is operative to translate the spoiler between a first position wherein the spoiler upper surface is substantially flush with the UAV outer surface, and second a position, wherein the spoiler upper surface is disposed substantially within the UAV body.