A propulsion system coupled to a vehicle. The system includes a convex surface, a diffusing structure coupled to the convex surface, and at least one conduit coupled to the convex surface. The conduit is configured to introduce to the convex surface a primary fluid produced by the vehicle. The system further includes an intake structure coupled to the convex surface and configured to introduce to the diffusing structure a secondary fluid accessible to the vehicle. The diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary fluid and secondary fluid.

An active flow control drag-induced damping reduction apparatus. The apparatus includes a variable frequency signal power supply; a jet generator defining an internal cavity and having pump member, and coupled to the variable frequency signal power supply to receive a control signal; a feedback sensor coupled to the pump member to generate a feedback signal measuring the reciprocating motion of the pump member; a detection circuit that receives the feedback signal and measures a difference compared to the variable frequency generator; and an adjustment circuit that receives the measured difference and tunes the variable frequency signal of the variable frequency signal power supply to maintain the jet generator at an optimum flow.

Methods and systems for controlling a fluid flow field near a surface are disclosed. In some embodiments, the system includes an array of oscillating bodies disposed on the surface to provide physical modification to the flow field. Fluid jets are also emitted from an outlet in the oscillating body to provide virtual modification of the flow field through momentum addition. Fluid jet sources, including synthetic jet generators such as piezoelectric drivers and sources of compressed fluids such as air or water, are positioned to be in fluid communication with the outlet at intervals during the oscillation of the oscillating body. Controlling the oscillation amplitude and frequency of the body, as well as the location of oscillating body outlets and frequency of fluid jet emission, have advantageous effects for the surface such as improved heat transfer properties and reduction in structural vibration and noise.

An aircraft is provided including a boundary layer ingestion fan mounted to an aft end of a fuselage. A stabilizer is mounted to the fuselage and extends between a root portion and a tip portion to define a span-wise length and extends between a leading edge and a trailing edge along the longitudinal direction. The stabilizer defines a line of maximum thickness that corresponds to the thickest cross sectional portion of the stabilizer along the span-wise length of the stabilizer. The line of maximum thickness is closer to the leading edge of the stabilizer proximate the root portion than at the tip portion, resulting in a pressure distribution that draws higher velocity air away from an inlet of the boundary layer ingestion fan.

An aircraft flow body includes a flow surface exposed to an airstream during flight, at least one structural component attached to an interior of the flow surface, at least one perforated area having a plurality of openings extending through the flow surface, a manifold positioned interior to the flow surface in fluid communication with the openings and upstream of the at least one structural component, and at least one suction duct having a first end in communication with the manifold and a second end placed exterior to the flow surface downstream of the structural component. The at least one suction duct includes a suction opening facing away from the first end and adapted for inducing a suction force into the at least one suction duct when the flow surface is exposed to the airstream during flight, thereby inducing a flow of air from through the openings to the suction opening.

A cross flow fan to be incorporated into an aircraft fuselage comprises an ingestion fan rotor to be positioned in a tail section of an aircraft fuselage to reduce boundary layer air from a top surface of the fuselage and to drive the air away from the top surface, and a drive arrangement for the ingestion fan rotor. An aircraft is also disclosed.

An aircraft is provided including a fuselage that extends along a longitudinal direction between a forward end and an aft end. A boundary layer ingestion fan is mounted to the fuselage at the aft end and is configured for ingesting boundary layer airflow off the surface of the fuselage. The fuselage defines a profile proximate the boundary layer ingestion fan that is optimized for ingesting a maximum amount of boundary layer air and improving propulsive efficiency of the aircraft. More specifically, the fuselage defines a cross sectional profile upstream of the boundary layer ingestion fan that has more cross sectional area in a top half relative to a bottom half as defined relative to a centerline of the boundary layer ingestion fan.

Fluid systems are described herein. An example embodiment of a fluid system has a lengthwise axis, a chord length, a first body portion, a second body portion, a spacer, and a fluid pressurizer. 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. The first body portion defines a cavity that is sized and configured to filter debris that enters the channel during use and provide a mechanism for removing the debris from the system.

An apparatus and system for combining aerodynamic design with engine power to increase synergy between the two and increase climb performance, engine-out performance, and fuel efficiency for a variety of aircraft or the like.

An aircraft propulsion system with a drag reduction portion adapted to reduce skin friction on at least a portion of the external surface of an aircraft. The drag reduction portion may include an inlet to ingest airflow. The aircraft may also have an internally cooled electric motor adapted for use in an aerial vehicle. The motor may have its stator towards the center and have an external rotor. The rotor structure may be air cooled and may be a complex structure with an internal lattice adapted for airflow. The stator structure may be liquid cooled and may be a complex structure with an internal lattice adapted for liquid to flow through. A fluid pump may pump a liquid coolant through non-rotating portions of the motor stator and then through heat exchangers cooled in part by air which has flowed through the rotating portions of the motor rotor. The drag reduction portion and the cooled electric motor portion may share the same inlet.