An air intake system comprising an air duct suitable for providing airflow to the inside of an aircraft, preferably to an auxiliary power unit; an inlet arranged at one end of the air duct; a skin surrounding the inlet; a plurality of slots arranged on the skin; a driving arrangement, a flap door connected to the driving arrangement, and a plurality of fins connected to the driving means. The driving arrangement is configured for moving the flap door between at least two positions, the positions being a closed position wherein the flap door closes the inlet, and an opened position wherein the flap door is driven away from the closed position. The driving arrangement is also configured for moving the plurality of fins such that the plurality of fins protrudes through the slots.

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 system includes a surface, an actuator, and processing circuitry. The surface includes one or more non-actuating zones and one or more actuatable zones. The actuator is configured to a flow property of a fluid that flows over the one or more actuatable zones of the surface. The processing circuitry is configured to obtain a value of a parameter of the fluid that flows over the surface, and operate the actuator to adjust the flow property of the fluid that flows over the one or more actuatable zones based on the value of the parameter of the fluid.

A process and machine configured to predict and preempt an undesired load and/or bending moment on a part of a vehicle resulting from an exogenous or a control input. The machine may include a predictor with an algorithm for converting parameters from a state sensed upwind from the part into an estimated normal load on the part and a prediction, for a future time, of a normal load scaled for a weight of the aerospace vehicle. The machine may: produce, using a state upwind from the part on the aerospace vehicle and/or a maneuver input, a predicted state, load and bending moment on the part at a time in the future; derive a command preempting the part from experiencing the predicted load and bending moment; and actuate the command just prior to the part experiencing the predicted state, thereby alleviating the part from experiencing the predicted load and bending moment.

A shock wave suppression device is configured to suppress a shock wave generated on a blade surface of a blade, the shock wave suppression device including a bump cover provided to follow the blade surface and deformable to protrude outward from the blade surface, and a displacing unit configured to displace the bump cover between a steady state to follow the blade surface and a deformed state to protrude outward from the blade surface. The bump cover has a curved shape in the deformed state configured to be a continuous surface from an upstream side to a downstream side in a flow direction of a fluid on the blade surface.

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.

Fluid systems are described herein. An example embodiment of a fluid system has a first body portion, a second body portion, a plurality of supports, a plurality of fluid pressurizers, and a plurality of ducts. The first body portion and the second body portion cooperatively define an injection opening, a suction opening, and a channel that extends from the injection opening to the suction opening. The fluid pressurizer is disposed within the channel cooperatively defined by the first body portion and the second body portion. Each duct of the plurality of ducts is disposed within the channel cooperatively defined by the first body portion and the second body portion.

Drag modification systems for aircraft and related methods. An example system for modifying drag on an aircraft includes a boundary layer intake plenum and an eductor. The eductor defines a primary inlet to receive a primary fluid, a secondary inlet in fluid communication with the intake plenum to receive a secondary fluid entrained from the intake plenum, and an outlet to exhaust a mixed flow including the primary fluid and the secondary fluid. The primary fluid is a motive fluid having flow parameters to generate a suction at the secondary inlet.

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.