The present invention relates to the field of aircraft turbomachine propellers. It more particularly concerns managing the risk of the blades of the propeller breaking, also known as the risk of uncontained engine rotor failure (UERF).
The invention applies to all types of aircraft, commercial and military, including propeller turbomachines such as turboprops for example or turbomachines with two contrarotating propellers known as “open rotor” turbomachines.
There are known from the prior art propeller turbomachines types in which the blades of the propeller are of variable pitch. Such propellers equip conventional turboprops and also turbomachines with two contrarotating propellers known as “open rotor” turbomachines A turbomachine propeller is known from the document WO20100116080, for example.
To meet specific standards, aircraft must provide a solution to the risk of the blades of the propeller breaking. In service, such blade fractures can in effect generate debris liable to damage the adjacent turbomachine and/or to damage the fuselage of the aircraft, for example at the level of a pressurized compartment delimited by that fuselage. To prevent damaging the fuselage, in particular when it delimits a pressurized compartment such as the passenger cabin, the fuselage may be equipped with an anti-debris shield that extends over a large angular sector of the part of the fuselage situated in line with the propeller. This shield represents a penalty in terms of mass and cost, however.
An alternative in the specific case of aircraft equipped with turbomachines attached to the aft part of the fuselage comprises moving the turbomachines aft so that their propellers are no longer situated in line with a pressurized compartment, but aft of a sealed bulkhead delimiting that compartment. However, this solution imposes lengthening the tail cone of the aircraft and therefore also leads to penalties in terms of mass and cost.
There is therefore a need to optimize the design of propeller turbomachines in relation to managing the risk of UERF.