公开(公告)号：US20190323452A1

公开(公告)日：2019-10-24

申请号：US16360606

申请日：2019-03-21

Applicant: ROLLS-ROYCE plc

Inventor： John R WELLS ,  Christopher A MOSLEY ,  Nicholas GRECH

IPC: F02K1/06 ,  F01D25/24 ,  F02K1/46

Abstract: A turbofan engine includes an outer fixed structure, the downstream terminal end of which terminates in a terminal plane substantially normal to the longitudinal axis of the engine. The radius R of the internal surface of the outer fixed structure in the terminal plane is a function R(ϕ) of azimuthal position ϕ such that the radius has a constant value R0 within a first azimuthal interval of 180°, a value greater than R0 at any azimuthal position within a second and fourth azimuthal intervals and a value less than R0 at any azimuthal position within a third azimuthal interval, the azimuthal intervals forming a total interval of 360° and the fourth interval being contiguous with the first. The engine may be mounted closer to the airframe of an aircraft than a turbofan engine having an outer fixed structure which is axisymmetric in its downstream terminal plane.