A propulsion system coupled to a vehicle. The system includes a diffusing structure and a conduit portion configured to introduce to the diffusing structure through a passage a primary fluid produced by the vehicle. The passage is defined by a wall, and the diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary fluid. A constricting element is disposed adjacent the wall. An actuating apparatus is coupled to the constricting element and is configured to urge the constricting element toward the wall, thereby reducing the cross-sectional area of the passage.

A propulsion system coupled to a vehicle. The system includes a diffusing structure and a conduit portion configured to introduce to the diffusing structure through a passage a primary fluid produced by the vehicle. The passage is defined by a wall, and the diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary fluid. A constricting element is disposed adjacent the wall. An actuating apparatus is coupled to the constricting element and is configured to urge the constricting element toward the wall, thereby reducing the cross-sectional area of the passage.

A vehicle, includes a main body. A fluid generator is coupled to the main body and produces a fluid stream. At least one tail conduit is fluidly coupled to the generator. First and second fore ejectors are coupled to the main body and respectively coupled to a starboard side and port side of the vehicle. The fore ejectors respectively comprise an outlet structure out of which fluid flows. At least one tail ejector is fluidly coupled to the tail conduit. The tail ejector comprises an outlet structure out of which fluid flows. A primary airfoil element includes a closed wing having a leading edge and a trailing edge. The leading and trailing edges of the closed wing define an interior region. The at least one propulsion device is at least partially disposed within the interior region.

A vehicle, includes a main body. A fluid generator is coupled to the main body and produces a fluid stream. At least one tail conduit is fluidly coupled to the generator. First and second fore ejectors are coupled to the main body and respectively coupled to a starboard side and port side of the vehicle. The fore ejectors respectively comprise an outlet structure out of which fluid flows. At least one tail ejector is fluidly coupled to the tail conduit. The tail ejector comprises an outlet structure out of which fluid flows. A primary airfoil element includes a closed wing having a leading edge and a trailing edge. The leading and trailing edges of the closed wing define an interior region. The at least one propulsion device is at least partially disposed within the interior region.

A propulsion system coupled to a vehicle. The system includes a diffusing structure and a conduit portion configured to introduce to the diffusing structure through a passage a primary fluid produced by the vehicle. The passage is defined by a wall, and the diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary fluid. A constricting element is disposed adjacent the wall. An actuating apparatus is coupled to the constricting element and is configured to urge the constricting element toward the wall, thereby reducing the cross-sectional area of the passage.

A propulsion system coupled to a vehicle. The system includes a diffusing structure and a conduit portion configured to introduce to the diffusing structure through a passage a primary fluid produced by the vehicle. The passage is defined by a wall, and the diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary fluid. A constricting element is disposed adjacent the wall. An actuating apparatus is coupled to the constricting element and is configured to urge the constricting element toward the wall, thereby reducing the cross-sectional area of the passage.

An aircraft includes a fuselage module and at least two vertical lift rotor modules supporting at least four rotor assemblies. Each rotor assembly is supported by a rotor boom having at least one boom free end and a boom mounting portion. Each rotor assembly has at least one vertical lift rotor mounted on the boom free end. Each boom mounting portion is removably couplable to the fuselage module. The vertical lift rotor modules are configured such that when coupled to the fuselage module, a pair of the rotor assemblies are located on each of laterally opposite sides of the fuselage module, and the rotor assemblies of each pair are respectively located forward of and aft of a wing center portion. A pair of wings are configured to be removably couplable to the wing center portion. The aircraft includes a forward thrust module removably couplable to the fuselage body.

This present disclosure relates generally to propulsion systems and, more particularly, to adaptive ducted fan propulsion systems for use with aircraft such as unmanned aerial vehicles. Embodiments of ADF systems in accordance with the present disclosure feature automatic, fast operation, increase the intake section of the air mass fed to a propeller, and can increase thrust by 35%-40% as compared to existing ducted fans.

A vehicle, includes a main body. A fluid generator is coupled to the main body and produces a fluid stream. At least one tad conduit is fluidly coupled to the generator. First and second fore ejectors are coupled to the main body and respectively coupled to a starboard side and port side of the vehicle. The fore ejectors respectively comprise an outlet structure out of which fluid flows. At least one tail ejector is fluidly coupled to the tail conduit. The tail ejector comprises an outlet structure out of which fluid flows A primary airfoil element includes a closed wing having a leading edge and a trailing edge. The leading and trailing edges of the closed wing define an interior region. The at least one propulsion device is at least partially disposed within the interior region.

A vehicle, includes a main body. A fluid generator is coupled to the main body and produces a fluid stream. At least one tad conduit is fluidly coupled to the generator. First and second fore ejectors are coupled to the main body and respectively coupled to a starboard side and port side of the vehicle. The fore ejectors respectively comprise an outlet structure out of which fluid flows. At least one tail ejector is fluidly coupled to the tail conduit. The tail ejector comprises an outlet structure out of which fluid flows A primary airfoil element includes a closed wing having a leading edge and a trailing edge. The leading and trailing edges of the closed wing define an interior region. The at least one propulsion device is at least partially disposed within the interior region.