In some embodiments, apparatuses are provided herein useful to sealing a gap between a movable flap and a stationary structure, such as a gap between a gas turbine engine nozzle flap and a corresponding sidewall. An apparatus for sealing such a gap may be a dynamic skirted leaf seal which may include a flap arm and a wall arm opposite the flap arm. A distal end portion of the flap arm may comprise a first skirt and the distal end portion of the wall arm may comprise a second skirt that engages the first skirt. When positioned in a gap between the movable flap and the stationary structure, the skirted leaf seal may exert a force to urge the flap arm towards the flap and to urge the wall arm towards the structure to seal the gap.

A nacelle assembly of a gas turbine engine includes an annular structure defining a central axis, and having a radially inward surface and a radially outward surface, the radially inward surface at least partially defining a bypass duct. An aft portion of the radially inward surface at least partially defines an axially extending convergent-divergent exit nozzle. A secondary nozzle flap is radially spaced from the aft portion of the radially inward surface. The secondary nozzle flap and the aft portion of the radially inward surface define a secondary bypass duct therebetween. The secondary nozzle flap is operably connected to the annular structure such that the secondary nozzle flap is selectably movable relative to the aft portion of the radially inward surface, thereby changing a cross-sectional area of a secondary bypass duct exit.

A system and method for vectoring the thrust of a supersonic, air-breathing engine. A thrust vectoring mechanism uses two asymmetrically staggered ramps; one placed at the throat, the other positioned at the exit lip of the nozzle of the engine to re-direct exhaust flow off-axis with the nozzle.

A propulsor system comprising a propulsor and an exhaust area control mechanism are described. The exhaust area control mechanism is connected to an outlet of the propulsor and is configured to vary the area through which air exits the propulsor system.

A propulsion system assembly includes a variable area inlet and an inlet duct. The variable area inlet includes an outer airflow inlet passage, an inner airflow inlet passage, an inlet structure and a center body structure. The outer airflow inlet passage is between the inlet structure and the center body structure. The inner airflow inlet passage is formed within the center body structure. The center body structure includes a valve configured to regulate air flow through the inner airflow inlet passage. The valve includes a first door configured to pivot between a closed position and an open position. The inlet duct is configured to receive air from the outer airflow inlet passage when the first door is in the closed position. The inlet duct is configured to receive air from the outer airflow inlet passage and the inner airflow inlet passage when the first door is in the open position.

A propulsion system assembly includes a variable area inlet and an inlet duct. The variable area inlet includes an outer airflow inlet passage, an inner airflow inlet passage, an inlet structure and a center body structure. The outer airflow inlet passage is between the inlet structure and the center body structure. The inner airflow inlet passage is formed within the center body structure. The center body structure includes a valve configured to regulate air flow through the inner airflow inlet passage. The valve includes a first door configured to pivot between a closed position and an open position. The inlet duct is configured to receive air from the outer airflow inlet passage when the first door is in the closed position. The inlet duct is configured to receive air from the outer airflow inlet passage and the inner airflow inlet passage when the first door is in the open position.

Disclosed is an exhaust nozzle for a gas turbine engine, the exhaust nozzle comprising an outer frame extending along a longitudinal direction, a convergent petal pivotably attached to the frame and extending axially downstream and radially inward from the pivot, radially within the frame, and a sealing hinge arrangement between an upstream member and a downstream member of the exhaust nozzle. One of the upstream member or the downstream member defines a cylindrical socket having an opening along a cylinder axis which receives a corresponding cylindrical hinge element the other of the downstream member or upstream member, where the upstream member is defined by the frame and the downstream member is the convergent petal; or the exhaust nozzle further comprises a divergent petal downstream of the convergent petal and pivotably attached to the convergent petal, the upstream member being the convergent petal and the downstream member being the divergent petal.

A two-dimensional variable area plug (2D VAP) nozzle assembly for a high-speed flight vehicle. In one embodiment, a 2D VAP nozzle assembly comprises a nozzle including a plurality of sidewalls; a plug body within the nozzle, the plug body abutting at least two of the plurality of sidewalls; a first convergent flap hingedly connected to at least one of the plurality of sidewalls; and a second convergent flap hingedly connected to at least one of the plurality of sidewalls. In one embodiment, the nozzle assembly includes only a first convergent flap and a second convergent flap, without diverging flaps. The 2D VAP nozzle assembly has a simplified design with reduced sidewall length, which results in reduced manufacturing and maintenance costs.

A rotating detonation engine can include an annular combustion chamber, an adjustable exhaust nozzle, and a nozzle actuator arrangement. The annular combustion chamber can have repetitive high frequency combustion and can include an outlet. The nozzle can be coupled to that outlet to receive exhaust reactants expelled therefrom. The nozzle can include elongated fins arranged in a conical shape having inner surfaces, outer surfaces, and distal ends. The fins can include outer and inner sets of fins, can contract toward a closed position, and can expand toward an open position. Distal ends of the fins can define a nozzle outlet having variable diameters. The nozzle actuator arrangement can have fin adjusters that adjust the fins between the closed and open positions when power is applied to a power transmitter coupled to the fin adjusters during engine operations.

The present vertical lift vehicle system can include a single internal combustion engine, a single propeller, and a plurality of small ducts. The small ducts can connect to a single main duct acting as a combustion chamber, wherein the combustion chamber combines air from the small ducts with propane, wherein when ignited the contents of the main duct produce added thrust to the vehicle as it exits the main duct.