Nacelle forward part of a propulsion assembly comprising an inclined stiffening frame
A nacelle forward part of an aircraft propulsion assembly, includes an air inlet lip at the front end, an internal structure and an external panel extending the lip, and an annular stiffening frame formed around an axis of revolution and comprising an internal peripheral edge linked to the internal structure and an external peripheral edge linked to the external panel. The stiffening frame presents an inclination relative to the axis of revolution, its slope being oriented towards the front end of the nacelle forward part. The stiffening frame is configured to deviate, outside the nacelle of the propulsion assembly, an object striking the stiffening frame. The stiffening frame so configured is capable of withstanding the impacts of objects without breaking while enabling the object striking the stiffening frame to be deviated towards the exterior of the nacelle.
1. An anterior part of a nacelle of an aircraft propulsive assembly, said anterior part having a front end allowing the inlet of air and a rear end, said anterior part comprising:
an air inlet lip arranged at said front end;
an inner structure extending an inner surface of the air inlet lip;
an outer panel extending an outer surface of the air inlet lip, the outer panel forming an outer aerodynamic surface of the anterior part;
an annular rigidifying frame around an axis of revolution, said rigidifying frame arranged at said rear end of said anterior part and linking said outer panel to said inner structure, said rigidifying frame comprising an inner peripheral edge linked to said inner structure and an outer peripheral edge linked to said outer panel; and
a rear flange comprising a front end and a rear end, said front end fixed to said inner peripheral edge of said rigidifying frame, said rear end adapted to be fixed to an engine flange,
wherein said rigidifying frame has an inclination relative to the axis of revolution, such that the rigidifying frame has a slope oriented toward the front end of said anterior part of the nacelle, said rigidifying frame configured to deflect out of the nacelle of the propulsive assembly, towards the outer aerodynamic surface, an object entering through the front end of the anterior part and striking said rigidifying frame
wherein the outer peripheral edge of the rigidifying frame is linked to said outer panel by an interface ring, and wherein the interface ring does not extend in continuity of the rigidifying frame.
2. The anterior part of a nacelle according to claim 1 , wherein the rear flange is deformable under the effect of an impact of the same direction as said axis of revolution of said rigidifying frame.
3. The anterior part of a nacelle according to claim 1 , further comprising a fixing part made of titanium or titanium alloy ensuring a link between said front end of said rear flange and said inner peripheral edge of said rigidifying frame.
4. The anterior part of a nacelle according to claim 1 , wherein the inclination of the rigidifying frame relative to its axis of revolution lies between 10° and 45°.
5. The anterior part of a nacelle according to claim 1 , wherein the rigidifying frame is made of composite material.
6. The anterior part of a nacelle according to claim 1 , wherein the rigidifying frame has a substantially domed form.
7. The anterior part of a nacelle according to claim 1 , wherein there is no frame forward of the rigidifying frame.
8. The anterior part of a nacelle according to claim 1 , wherein the interface ring has a width of between 20 and 150 millimeters.
9. The anterior part of a nacelle according to claim 1 , wherein the interface ring has a thickness of between 1 and 3 millimeters.
10. The anterior part of a nacelle according to claim 1 , wherein the interface ring is made of a metal.
11. The anterior part of a nacelle according to claim 10 wherein the interface ring is made of aluminum, aluminum alloy or titanium.
12. An aircraft propulsive assembly comprising a nacelle, said nacelle comprising an anterior part according to claim 1 .
13. The anterior part of a nacelle according to claim 1 , wherein the rigidifying frame and the interface ring forming a first angle (β) less than 180°.
14. The anterior part of a nacelle according to claim 13 , wherein the rigidifying frame and the interface ring form a first angle (β) greater than or equal to 120° and less than 180°.
15. The anterior part of a nacelle according to claim 14 , wherein the first angle (β) lies between 120° and 170°.