Abstract: A system 100 for increasing the efficiency of an axial ducted fan 105 includes, a duct 110 for enclosing the axial ducted fan 105, wherein the axial ducted fan 105 is operationally mounted inside the duct 110. In use, the system 100 further includes, a shaft 115 operably connected to the axial ducted fan 105 for facilitating rotation of the axial ducted fan 105 inside the duct 110; and, a static fan 120 operably positioned parallel to the axial ducted fan 105. In use, the static fan 120 includes same number of blades as the axial ducted fan 105. The system 100 further includes a propulsion efficiency improvement mechanism 125 operably positioned inside the duct 110 for controlling, (a) a position of the static fan 120, and, (b) speed of rotation of the axial ducted fan 105.

Abstract: A system for increasing the efficiency of low pressure axial fans, includes, a low pressure axial fan including multiple first blades, and, a vortex generator operably coupled to the low pressure axial fan via a shaft. In use, the vortex generator includes multiple second blades. In further use, the low pressure axial fan is configured to operate in an operational mode and the vortex generator is configured to operate in a stationary mode.