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Lemont Aircraft Corporation

Harold E Lemont

Andrew I Lemont

A low-aspect ratio propeller system is provided with a multiple ring structure formed with a plurality of circular or non-circular, annular, narrow equivalent air foil rings which are held by rails in a predetermined relationship with the propeller blades. The upstream ring is located downstream from the tip vortex of the propeller within the axial span of the propeller. One or more additional downstream-located rings are used so as to provide at least one annular multiple ring-defined pump aperture through which peripheral vortices generated by the propeller blades or fan blades may enhance the mass flow. In one propeller system, a low-aspect-ratio propeller is employed with high blade angles of attack and non-stall capability to generate strong vortices which enhance the beneficial effect of the multiple ring structure. These vortices increase thrust because their induction action on the rings increase beneficial ring flow circulation. Augmented ring flow reduces the velocities in the expanding wake by increasing the mass flow. The destruction of tip and root vortices reduces noise. The multiple ring structure also serves as a guard to protect people and animals against the rotating propeller. A plurality of embodiments are shown and described.

Propulsive thrust ring system

Improvements to a propulsion thrust apparatus are described wherein a propeller is surrounded by a ring cage structure with which propeller tip vortices are converted to useful mass flow with a plurality of rings whose spacing from each other and the propeller are selected so that in one embodiment at least one ring is placed inside an enclosure and the others are outside. The operation of the propeller then produces an enhanced circulation of the air inside the enclosure without hot spots. In another embodiment, the rings are segmented to provide additional vortices for enhancement of the propeller mass flow. With another embodiment, at last one of the rings are provided with discontinuities on the inside edge to promote the generation of vortices that improve mixing of tip vortices and provide a noise reduction effect. In still another embodiment, the rings are helically shaped and a heater can be incorporated inside the helical ring or the entire ring is made of an appropriately helically shaped heater element. With still another embodiment, a pressure chamber is formed in front of an enclosure or duct or housing and a pair of fans with ring cage structures are placed in tandem partially inside the chamber and partially inside the duct or enclosure to provide an enhanced sealing and increased static pressure handling capability. Other embodiments are described.

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Seymour, CT, United States of America

Harold E Lemont