Flattened nacelle of a turbojet engine
A nacelle includes an outer structure provided with a thrust reverser and a front frame, a movable cowl, and an inner structure covering a downstream section of a turbojet engine. The outer structure and the inner structure define a flow stream of an air flow. In particular, the connection of the front frame and diversion cascade of the thrust reverser which is mounted on a reduced transverse section area of the movable cowl is centered on an axis offset relative to an axis on which the connection of the front frame and the diversion cascade mounted on the remainder of the periphery of the movable cowl is centered.
1. A nacelle, comprising:
an outer structure provided with a thrust reverser device and a front frame; and
an inner structure covering a downstream section of a turbojet engine,
the outer structure and the inner structure defining a flow stream of an air flow of the turbojet engine,
the thrust reverser device comprising:
one movable cowl translating along a direction parallel to a longitudinal axis of the nacelle, the movable cowl configured to alternately switch from a closing position to an opening position, wherein in the closing position, the movable cowl provides aerodynamic continuity of the front frame, and in the opening position, the movable cowl opens a passage in the nacelle for the air flow to be diverted, the movable cowl having a non-constant cross section over a periphery of the flow stream of the air flow; and
diversion cascades for diverting at least one part of the air flow of the turbojet engine through the passage, at least one of the diversion cascades being mounted on the front frame at an upstream end thereof by a first front frame connection, and at least another one of the diversion cascades being mounted on the front frame by a second front frame connection, the first frame connection and the second frame connection defining an arc,
wherein the first front frame connection is mounted on a reduced cross-sectional area of the movable cowl and is centered on a first front frame axis offset relative to a second front frame axis at which the second front frame connection is mounted on a remainder of a periphery of the movable cowl is centered.
2. The nacelle according to claim 1 , wherein the outer structure further comprises a rear frame on which a downstream end of each diversion cascade is mounted, a first rear frame connection of the rear frame and at least one diversion cascade being mounted on the reduced cross-sectional area of the movable cowl and is centered on a first rear frame axis offset relative to a second rear frame axis on which a second rear frame connection of the rear frame and at least another of the diversion cascades being mounted on the remainder of the periphery of the movable cowl and is centered, wherein the first rear frame connection and the second rear frame connection define an arc.
3. The nacelle according to claim 1 , wherein the first front frame axis and the second front frame axis on which each diversion cascade is respectively centered is configured such that a radial distance of each diversion cascade relative to a corresponding center is identical over the entire periphery of the flow stream.
4. The nacelle according to claim 1 , wherein the front frame comprises an element forming a support for at least one diversion cascade shaped to be centered on the first front frame axis in the reduced cross-sectional area of the movable cowl and the second front frame axis on the remainder of the periphery of the movable cowl.
5. The nacelle according to claim 4 , wherein the second front frame axis corresponds to the longitudinal axis of the nacelle.
6. The nacelle according to claim 2 , wherein the rear frame comprises an element forming a support for at least one diversion cascade shaped to be centered on a third axis in the reduced cross-sectional area of the movable cowl and a fourth axis on the remainder of the periphery of the movable cowl, the fourth axis being offset relative to the third axis.
7. The nacelle according to claim 6 , wherein the fourth axis corresponds to the longitudinal axis of the nacelle.
8. The nacelle according to claim 1 , wherein at least one of an upstream and a downstream end of at least one diversion cascade is shaped to be centered on a fifth axis in the reduced cross-sectional area of the movable cowl and a sixth axis on the remainder of the periphery of the movable cowl, the sixth axis being offset relative to the fifth axis.
9. The nacelle according to claim 8 , wherein the sixth axis corresponds to the longitudinal axis of the nacelle.
10. The nacelle according to claim 1 wherein the movable cowl has the reduced cross-sectional area on at least one side of upper and lower beams connected to the nacelle.
11. The nacelle according to claim 2 , wherein a first axis offset, on which the connection of the front frame or the rear frame and the at least one diversion cascade mounted on the reduced upper cross-sectional area of the movable cowl is centered, is different from a second axis offset on which the connection of the front frame, or respectively the rear frame, and at least one diversion cascade mounted on the reduced lower cross-sectional area of the movable cowl is centered.
12. The nacelle according to claim 1 , wherein the at least one diversion cascade is, at least partly, movable in translation or in rotation.