US 12,404,007 B2
Ducted fan aircraft propulsion system
Jonathan M Parsons, Derby (GB); Elyse M Marshall, Derby (GB); Sibylle Rerolle, London (GB); and Nadav Grunberg, London (GB)
Assigned to ROLLS-ROYCE plc, London (GB)
Filed by ROLLS-ROYCE plc, London (GB)
Filed on Aug. 2, 2024, as Appl. No. 18/792,688.
Claims priority of application No. 2313173 (GB), filed on Aug. 30, 2023.
Prior Publication US 2025/0074577 A1, Mar. 6, 2025
Int. Cl. B64C 11/00 (2006.01); B64C 39/06 (2006.01)
CPC B64C 11/001 (2013.01) [B64C 39/062 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A ducted fan aircraft propulsion system, comprising:
a duct;
a central body portion having first and second ends and extending through the duct;
a payload portion extending from the first end of the central body portion, wherein an upper part of an outer surface of the payload portion defines a spheroidal shape; and
a rotor extending across an internal volume of the duct from the central body portion,
wherein the duct comprises an outwardly flared inlet end such that an inlet air flow passage between the central body portion and an inner surface of the duct has a sectional area that decreases from the inlet end of the duct to the rotor, and
wherein a cross-sectional shape of the duct forms an annular wing having a decreasing cross-section from the inlet end of the duct to an outlet end of the duct.