Abstract: A member may have a primary major surface and a secondary major surface. The member may form an array of apertures extending from the primary major surface to the secondary major surface. The array of apertures includes at least one aperture comprising two or more conduits. The axis of each conduit intersects the axis of each other conduit in the aperture. The cross-section of at least one of the conduits perpendicular to its axis may be circular. In some embodiments, an aperture may comprise two or three conduits.

Abstract: An aircraft is disclosed having a boundary layer ingestion propulsor. The aircraft comprises an elongated fuselage extending between a nose section and a tail section. The fuselage has an upswept underside in the tail section. The boundary layer ingestion propulsor is positioned in the tail section. The propulsor comprises a fan radially encased by a nacelle circumscribing the fuselage. The nacelle defines a leading edge line extending from a top dead center to a bottom dead center of the nacelle intersecting an axis of rotation of the fan at an angle no greater than seventy degrees.

Abstract: A member may have a first major surface and a second major surface. The first major surface may define a plurality of riblets that may extend in the direction of a primary flow. The member may form an array of conduits that extend from an entrance port at the second major surface to an exit port at the first major surface. Each of the exit ports may intersect two or more riblets. Each of the exit ports may intersect a riblet that intersect another of the exit ports.

Abstract: An aircraft is disclosed having a boundary layer ingestion propulsor. The aircraft comprises an elongated fuselage extending between a nose section and a tail section. The fuselage has an upswept underside in the tail section. The boundary layer ingestion propulsor is positioned in the tail section. The propulsor comprises a fan radially encased by a nacelle circumscribing the fuselage. The nacelle defines a leading edge line extending from a top dead center to a bottom dead center of the nacelle intersecting an axis of rotation of the fan at an angle no greater than seventy degrees.

Abstract: A member may have a primary major surface and a secondary major surface. The member may form an array of apertures extending from the primary major surface to the secondary major surface. The array of apertures includes at least one aperture comprising two or more conduits. The axis of each conduit intersects the axis of each other conduit in the aperture. The cross-section of at least one of the conduits perpendicular to its axis may be circular. In some embodiments, an aperture may comprise two or three conduits.

Abstract: A member may have a first major surface and a second major surface. The first major surface may define a plurality of riblets that may extend in the direction of a primary flow. The member may form an array of conduits that extend from an entrance port at the second major surface to an exit port at the first major surface. Each of the exit ports may intersect two or more riblets. Each of the exit ports may intersect a riblet that intersect another of the exit ports.