The Augmented Fan is a new, low noise fan  technology that allows for a 40-50 % increase in flow @ equal noise levels. The Augmented Fan’s difference in operation can be observed with the  addition of a patented multiple ring structure or ringcage. The ringcage acts as a radial flow ejector in combination with an axial fan. Utilizing  the normally-wasted energy in the fan tip vortex the Augmented Fan induces added air into the normal propeller flow. The added inflow through the rings destroys the tip vortex and helps maintain boundary layer control; the smoother flow through the system eliminates fan duct stall  and reduces noise 6 - 8 dbA.