A propulsion system for an aircraft, comprising at least one rotor and a nacelle fairing extending around the at least one rotor with respect to an axis of rotation of the rotor, the nacelle fairing comprising: an upstream section forming an inlet section of the nacelle fairing; a downstream section wherein a downstream end forms an outlet section of the nacelle fairing; and an intermediate section connecting the upstream and downstream sections, wherein the downstream section comprises a radially inner wall and a radially outer wall made of a deformable shape memory material, and further comprising at least one actuator mechanism with at least one cylinder configured to cooperate with one or more components, projections, etc., embedded in an inner surface of the radially outer wall so as to vary an outer diameter of the outlet section between a minimum diameter and a maximum diameter.

Flexible aft cowls are disclosed. In some examples, an aircraft engine having a flexible aft cowl is disclosed. In some examples, the aircraft engine comprises an aft cowl having a flexible portion defining a throat area adjacent an engine core nozzle of the aircraft engine. In some examples, the flexible portion to move radially between a first radial position in response to pressure within a nacelle not exceeding a pressure threshold and a second radial position in response to pressure within the nacelle exceeding the pressure threshold. In some examples, the throat area defined by the flexible portion is greater when the flexible portion is in the second radial position than when the flexible portion is in the first radial position.

Flexible aft cowls are disclosed. In some examples, an aircraft engine having a flexible aft cowl is disclosed. In some examples, the aircraft engine comprises an aft cowl having a flexible portion defining a throat area adjacent an engine core nozzle of the aircraft engine. In some examples, the flexible portion to move radially between a first radial position in response to pressure within a nacelle not exceeding a pressure threshold and a second radial position in response to pressure within the nacelle exceeding the pressure threshold. In some examples, the throat area defined by the flexible portion is greater when the flexible portion is in the second radial position than when the flexible portion is in the first radial position.

A propulsion system for an aircraft includes a rotor and a nacelle fairing that extends around the rotor in relation to an axis. The nacelle fairing includes an upstream portion forming an inlet section of the nacelle fairing as well as a downstream portion, a downstream end of which forms an outlet section of the nacelle fairing. The downstream portion includes radially inner and outer walls, both of which are made of a deformable shape memory material. The wall has independently actuatable piston actuator mechanisms, each actuator mechanism being actuatable independently of the others and being designed to cooperate with means built into an inner surface of the wall to deform the wall in a radial direction in relation to the axis under the effect of a predetermined displacement command.

A variable-section nozzle for an aircraft nacelle includes a deformable portion of which is movable between a narrow section position and a wide section position. In particular, the variable-section nozzle includes piezoelectric actuators and a controller to control the piezoelectric actuators in order to displace the deformable portion between the narrow and wide section positions. The piezoelectric actuators can be disposed on at least one faces of the deformable portion or be disposed end-to-end to form actuating rods.

Flexible aft cowls are disclosed. In some examples, an aircraft engine having a flexible aft cowl is disclosed. In some examples, the aircraft engine comprises an aft cowl having a flexible portion defining a throat area adjacent an engine core nozzle of the aircraft engine. In some examples, the flexible portion to move radially between a first radial position in response to pressure within a nacelle not exceeding a pressure threshold and a second radial position in response to pressure within the nacelle exceeding the pressure threshold. In some examples, the throat area defined by the flexible portion is greater when the flexible portion is in the second radial position than when the flexible portion is in the first radial position.

Flexible aft cowls are disclosed. In some examples, an aircraft engine having a flexible aft cowl is disclosed. In some examples, the aircraft engine comprises an aft cowl having a flexible portion defining a throat area adjacent an engine core nozzle of the aircraft engine. In some examples, the flexible portion to move radially between a first radial position in response to pressure within a nacelle not exceeding a pressure threshold and a second radial position in response to pressure within the nacelle exceeding the pressure threshold. In some examples, the throat area defined by the flexible portion is greater when the flexible portion is in the second radial position than when the flexible portion is in the first radial position.

A propulsion system for an aircraft, comprising at least one rotor and a nacelle fairing extending around the at least one rotor with respect to an axis of rotation of the rotor, the nacelle fairing comprising: an upstream section forming an inlet section of the nacelle fairing; a downstream section wherein a downstream end forms an outlet section of the nacelle fairing; and an intermediate section connecting the upstream and downstream sections, wherein the downstream section comprises a radially inner wall and a radially outer wall made of a deformable shape memory material, and further comprising at least one actuator mechanism with at least one cylinder configured to cooperate with one or more components, projections, etc., embedded in an inner surface of the radially outer wall so as to vary an outer diameter of the outlet section between a minimum diameter and a maximum diameter.

A propulsion system for an aircraft includes a rotor and a nacelle fairing that extends around the rotor in relation to an axis. The nacelle fairing includes an upstream portion forming an inlet section of the nacelle fairing as well as a downstream portion, a downstream end of which forms an outlet section of the nacelle fairing. The downstream portion includes radially inner and outer walls, both of which are made of a deformable shape memory material. The wall has independently actuatable piston actuator mechanisms, each actuator mechanism being actuatable independently of the others and being designed to cooperate with means built into an inner surface of the wall to deform the wall in a radial direction in relation to the axis under the effect of a predetermined displacement command.

The invention relates to a propulsion system (1, 1) for an aircraft, comprising a rotor (2) and a nacelle failing (3) that extends around said rotor in relation to an axis (X) and includes an upstream portion (10) forming an inlet section (BA) of the nacelle fairing (3) as well as a downstream portion (20), a downstream end (21) of which forms an outlet section (BF) of the nacelle fairing (3); and characterized in that the downstream portion (20) has a radially inner wall (20a) and a radially outer wall (20b), both of which are made of a deformable shape memory material, and in that the downstream end (21) includes pneumatic or hydraulic actuators (23, 23) extending in different consecutive angular sectors about said axis (X), each actuator being independently actuatable and being configured to deform, in a direction that extends radially in relation to said axis (X) and is centered angularly in relation to its angular sector, under the effect of a predetermined control pressure.