A method of providing active flow control for an aircraft includes cooling a liquid coolant in a heat exchanger by circulating a cooling airflow through the heat exchanger, and providing fluid communication between the cooling airflow and a boundary layer flow of at least one flight control surface of the aircraft. The cooling airflow affects the boundary layer flow of the flight control surface(s) to provide active flow control. A method of cooling an engine core of an engine assembly includes circulating a cooling fluid through the engine core, and cooling the cooling fluid with a cooling airflow used to provide active flow control to a flight control surface of the aircraft. An active flow control system for an aircraft is also discussed.

An airfoil for flow control is disclosed having an outer skin in contact with an ambient air flow, wherein the outer skin extends between a leading edge and a trailing edge with two opposite lateral sides, and surrounds an interior space. The outer skin comprises a porous section in the area of the leading edge, a pressure chamber arranged in the interior space and fluidly connected to the porous section, an air inlet fluidly connected to the pressure chamber, and an air outlet fluidly connected to the pressure chamber.

An airfoil for flow control is disclosed having an outer skin in contact with an ambient air flow, wherein the outer skin extends between a leading edge and a trailing edge with two opposite lateral sides, and surrounds an interior space. The outer skin comprises a porous section in the area of the leading edge, a pressure chamber arranged in the interior space and fluidly connected to the porous section, an air inlet fluidly connected to the pressure chamber, and an air outlet fluidly connected to the pressure chamber.

A hybrid wing aircraft has an engine embedded into a body of the hybrid wing aircraft. The embedded engine has a fan that is received within a nacelle. The body of the aircraft provides a boundary layer over a circumferential portion of a fan. A system delivers additional air to correct fan stability issues raised by the boundary layer.

A hybrid wing aircraft has an engine embedded into a body of the hybrid wing aircraft. The embedded engine has a fan that is received within a nacelle. The body of the aircraft provides a boundary layer over a circumferential portion of a fan. A system delivers additional air to correct fan stability issues raised by the boundary layer.

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.

A drag reduction system an aircraft having an aircraft component is disclosed including a skin panel having an inner surface and an outer surface for contact with an ambient flow, the outer surface includes an upstream area for laminar flow and a downstream area for turbulent flow and/or transitional flow, the skin panel includes a plurality of micro pores for blowing air from inside the aircraft component into the ambient flow.

An aircraft includes a fuselage extending between a forward end and an aft end; a propulsor mounted to the fuselage at the aft end of the fuselage, the propulsor comprising an outer nacelle, the outer nacelle defining an inlet to the propulsor; and a deployable assembly attached to at least one of the fuselage or the outer nacelle and moveable between a stowed position and an engaged position. The deployable assembly alters an airflow towards the propulsor or into the propulsor through the inlet defined by the outer nacelle when in the engaged position. The propulsor further comprises a tail cone, wherein the outer nacelle defines an exhaust with the tail cone, and wherein the plurality of nacelle panels are movable generally along the axial centerline to a position at least partially aft of the exhaust of the outer nacelle when in the engaged position.

An aircraft includes a fuselage extending between a forward end and an aft end; a propulsor mounted to the fuselage at the aft end of the fuselage, the propulsor comprising an outer nacelle, the outer nacelle defining an inlet to the propulsor; and a deployable assembly attached to at least one of the fuselage or the outer nacelle and moveable between a stowed position and an engaged position. The deployable assembly alters an airflow towards the propulsor or into the propulsor through the inlet defined by the outer nacelle when in the engaged position. The propulsor further comprises a tail cone, wherein the outer nacelle defines an exhaust with the tail cone, and wherein the plurality of nacelle panels are movable generally along the axial centerline to a position at least partially aft of the exhaust of the outer nacelle when in the engaged position.

Systems, methods, lift fans, and aircraft involving active flow control of a ducted fan or fan-in-wing configuration are described.