A panel for an active laminar flow control arrangement may comprise a longitudinal wall and one or more division walls extending from the longitudinal wall and extending between the first end and the second end. The panel may be coupled to a nacelle outer skin via a plurality of adhesive fasteners pre-installed onto an inner surface of the outer skin and onto stiffeners and/or stringers associated with the outer skin.

Active surface structures comprise an exposed surface, a controlled group of MEMS (micro-electro-mechanical system) actuators, and a controlled region of the exposed surface corresponding to the controlled group. The controlled region has a first state, and a second state that is less textured than the first state. Active surface structures may be part of an apparatus that includes a controller and/or one or more sensors. The controller, sensors, and the controlled region may form a feedback loop in which the active surface structure is actively controlled.

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.

An intentional fluid manipulation apparatus (IFMA) assembly with a first thrust apparatus that imparts a first induced velocity to a local free stream flow during a nominal operation requirement. The first thrust apparatus creates a streamtube. A second thrust apparatus is located in a downstream portion of the streamtube. The second thrust apparatus imparts a second induced velocity to the local free stream flow. The second induced velocity at the location of the second thrust apparatus has a component in a direction opposite to the direction of the first induced velocity at the location of the second thrust apparatus.

A system includes a surface having a fluid flowing over the surface. The fluid includes a flow regime having a streamwise length scale greater than about 100 times η and less than about 100,000 times η, where η is a viscous length scale of the flow regime, and a convective time scale greater than about 10η′ and less than about 10,000η′, where η′ is a viscous time scale of the flow regime. The system includes a controller that causes at least one of motion the surface to modify fluid flow in the flow regime based on the streamwise length scale and the convective time scale or motion of the flow regime based on the streamwise length scale and the convective time scale.

Aircrafts having foldable wings are disclosed. An example aircraft includes a fixed wing portion, a foldable wing tip, and a hinge interface to pivotally couple the foldable wing tip and the fixed wing portion. The hinge interface has a first hinge defining a hinge axis that is substantially parallel to a fuselage centerline. The first hinge has a first dimension in a spanwise direction and a second dimension in a chordwise direction. The first dimension is greater than the second dimension.

Disclosed herein is a VTOL tilt-wing aircraft that serves as a 4-6 passenger airliner for scheduled service between city centers and that is optimized for travel distances from 100-500 miles fully loaded with passengers and fuel. The VTOL aircraft solves technical, cost, and time problems inherent in other forms of transportation, including, but not limited to, rail, passenger airlines, and helicopters. The VTOL aircraft (1) takes off and lands like a helicopter, (2) flies fast like a jet, and (3) costs less than or comparable to a helicopter.

A method for improving performance in an aircraft having a winglet coupled to a wing, the winglet having a leading edge and a trailing edge continuously transitioning from a leading edge and trailing edge of the wing. The method includes coupling a wing tip to the winglet. The wing tip may include a curved leading edge from the winglet leading edge to a leading end point, a curved trailing edge from a winglet trailing edge to a trailing end point, and an end segment connecting the leading end point and the trailing end point. The end segment may be swept back from the trailing end point to the leading end point at an end segment angle.

Described herein is a process for producing a structured article (A1M1) in which a material (M1) including at least one micro- and/or nanostructured surface (SU1) containing a plurality of micro-scale and/or nano-scale surface elements is covered with an at least partially cured coating layer (C2) to provide a composite (M1C2), said composite (M1C2) is attached to an object (A1) and the coating layer (C2) is at least partially peeled off to provide the structured article (A1M1). Also described herein is a composite (M1C2) in which the surface elements of the material (M1) are covered by a protective coating layer (C2).

A noise attenuation element can be arranged for connection to an air directing structure such as a wing flap. The element has a non-uniform lattice density across at least a portion of the body of the element.