Methods for optimizing Boundary Layer Control (BLC) systems and related systems (e.g. a Laminar Flow Control (LFC) system or systems, a Static Pressure Thrust (SPT) system or systems, a Boundary Layer Ingestion (BLI)/Wake Immersed Propulsion (WIP) system or systems, and/or low-dissipation BLC fluid-movement system or systems) to operate in concert with each other and a bellows air-moving system are disclosed.

The invention discloses a propeller-driven helicopter or airplane which comprises a fuselage and a propeller comprising a plurality of blades, wherein a plurality of pressure pipes are uniformly distributed between windward sides and leeward sides of the blades; a plurality of first inlets are formed in the windward sides and are communicated with outside via first channels in the blades and second outlets at tails of the blades; a high-pressure fluid of a low-speed fluid layer formed when a fluid flows through the leeward sides in a widthwise direction flows towards a low-pressure fluid of a high-speed fluid layer formed when the fluid flows through the first inlets, the first channels and the second outlets; and an upward pressure generated by the high-pressure fluid is opposite to a downward pressure generated by an external fluid above the windward sides, so that a fluid pressure above the propeller is decreased.

A vertical tail unit (7) for flow control including: an outer skin (13) in contact with an ambient air flow (21), wherein the outer skin (13) extends between a leading edge (23) and a trailing edge (25), and surrounds an interior space (29), and wherein the outer skin (13) includes a porous section (31) in the area of the leading edge (23), a pressure chamber (15) arranged in the interior space (29), wherein the pressure chamber (15) is fluidly connected to the porous section (31), an air inlet (17) provided in the outer skin (13), wherein the air inlet (17) is fluidly connected to the pressure chamber (15), wherein the air outlet (19) is fluidly connected to the pressure chamber (15). The vertical tail unit (7) has reduced drag and an increased efficiency because the air inlet (17) is formed as an opening (35) in the outer skin (13) at the leading edge (23).

A boundary layer suction design uses a wingtip vortex core for a lift-generating body with optimized aerodynamic performances. Holes or slots (6), connected to a core or center of a wingtip vortex of the lift generating body via a plenum (9) and pipe (7) with its outlet (8) sticking out from a surface (1) experiencing low pressure, sucked a part of the boundary layer to delay flow transition or separation. Thus, with a more stable boundary layer, the lift is increased while the drag is reduced.

An aircraft defines a longitudinal direction and includes a fuselage extending between a forward end and an aft end along the longitudinal direction of the aircraft. An aft engine is mounted to the aft end of the fuselage. The aft engine further includes a nacelle including a forward section. An airflow duct extends at least partially through the nacelle of the aft engine and defines an outlet on the forward section of the nacelle for providing an airflow to the forward section of the nacelle.

Variable-porosity panel systems and associated methods. A variable-porosity panel system includes a panel assembly with an exterior layer defining a plurality of exterior layer pores and a sliding layer adjacent to the exterior layer and defining a plurality of sliding layer pores. The variable-porosity panel system additionally includes a shape memory alloy (SMA) actuator configured to translate the sliding layer relative to the exterior layer to modulate a porosity of the panel assembly. The SMA actuator includes an SMA element configured to exert an actuation force on the sliding layer and at least partially received within an SMA element receiver of the sliding layer. The SMA element extends out of the sliding layer only at a sliding layer first end. A method of operating the variable-porosity panel system includes assembling the variable-porosity panel system and/or transitioning the panel assembly of the variable-porosity panel system among the plurality of panel configurations.

The fluid-dynamic structure comprises a fluid-dynamic exterior having a flow-augmented surface and a passive drag reduction system comprising a flow-repositioning duct having an inlet and an outlet that extend through the fluid-dynamic exterior. Under operative conditions, the passive drag reduction system is configured to direct a captured fluid stream into the inlet, through the flow-repositioning duct, and out of the outlet as a buffering fluid stream that flows along the flow-augmented surface. The inlet and the outlet are conformed and/or positioned such that, under the operative conditions, a total pressure at the inlet is greater than a total pressure at the outlet. The methods comprise flowing a bulk fluid stream across the fluid-dynamic exterior, establishing a pressure differential between the inlet and the outlet, and directing the captured fluid stream into the inlet and out of the outlet to flow along the flow-augmented surface as the buffering fluid stream.

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.

A system for suction of the boundary layer of a wing and protection against icing of this wing includes a wall including micro-perforations and delimiting a leading edge extended by a pressure-side wall and by a suction-side wall. The system also includes a perforated tube running along the leading edge, an exhaust duction for sucking air from this tube in order to suck the boundary layer successively via the micro-perforations of the wall and via the perforations of the tube, and a supply duct for blowing hot air into this perforated tube during a phase of protection against icing, this hot air being discharged successively via the perforations of the tube and via the micro-perforations of the wall.

A boundary-layer-influencing aerodynamic part comprises a carrier element provided with at least one air passage aperture for guiding an air flow through the carrier element, an air guiding layer disposed on the carrier element and a cover layer constituting at least a part of a flow surface and being configured to have air flow there through at least in sections. The air guiding layer is configured to have air flow there through with an air flow supplied to the part, at least in certain operating phases of the part, through the cover layer and flowing in the direction of the carrier element or through the air passage aperture of the carrier element and flowing in the direction of the cover layer. The cover layer is applied directly to the air guiding layer via an additive manufacturing method.