Abstract: Methods and apparatuses for controlling airflow proximate to engine/airfoil systems are disclosed. In one embodiment, an aircraft system includes an airfoil and an engine unit at least proximate to the airfoil with a gap between a portion of the airfoil and a portion of the engine unit. The system can further include a flow control device proximate to the gap and positionable among at least three stationary positions, including a retracted position in which the gap has a first area through which fluid can flow, a first extended position in which the gap is at least approximately aerodynamically sealed, and a second extended position in which the gap has a second smaller area through which fluid can flow. A control system can be coupled to the flow control device to move the flow control device among these positions.

Abstract: Methods and apparatuses for controlling airflow proximate to engine/airfoil systems are disclosed. In one embodiment, an aircraft system includes an airfoil and an engine unit at least proximate to the airfoil with a gap between a portion of the airfoil and a portion of the engine unit. The system can further include a flow control device proximate to the gap and positionable among at least three stationary positions, including a retracted position in which the gap has a first area through which fluid can flow, a first extended position in which the gap is at least approximately aerodynamically sealed, and a second extended position in which the gap has a second smaller area through which fluid can flow. A control system can be coupled to the flow control device to move the flow control device among these positions.

Abstract: A scarf nozzle for a jet engine supported within a nacelle. The scarf nozzle is at an aft end of the nacelle. The scarf nozzle includes a first trailing edge portion and a second trailing edge portion. The second trailing edge portion is disposed aft of the first trailing edge portion. The scarf nozzle is configured to allow the nacelle to be integrated closer to a wing without adversely affecting the pressure gradient between the nacelle and the wing. The scarf nozzle allows a portion of an exhaust plume exiting the aft end of the nacelle to interact more favorably with an airflow along one or more surfaces adjacent the nacelle, thus delaying the onset of adverse pressure gradients and the formation of shock waves between the nacelle and the adjacent surfaces and between the adjacent surfaces and the exhaust plume.

Abstract: A scarf nozzle for a jet engine supported within a nacelle. The scarf nozzle is at an aft end of the nacelle. The scarf nozzle includes a first trailing edge portion and a second trailing edge portion. The second trailing edge portion is disposed aft of the first trailing edge portion. The scarf nozzle is configured to allow the nacelle to be integrated closer to a wing without adversely affecting the pressure gradient between the nacelle and the wing. The scarf nozzle allows a portion of an exhaust plume exiting the aft end of the nacelle to interact more favorably with an airflow along one or more surfaces adjacent the nacelle, thus delaying the onset of adverse pressure gradients and the formation of shock waves between the nacelle and the adjacent surfaces and between the adjacent surfaces and the exhaust plume.