This application relates to a hollow fan blade for a gas turbine engine, wherein a unique structure is provided in the core of the blade.
Gas turbine engines are known, and typically include a fan moving air, with part of the air going into a compressor in the core of the engine, and the rest of the air bypassing the core. From the compressor the air passes into a combustion section where it is mixed with fuel and ignited. Products of this combustion pass downstream over turbine rotors, driving them to rotate.
Historically, the fan has rotated at the same speed as a turbine rotor. More recently, a gear reduction is provided to drive the fan at a slower speed than the rotor.
The use of the gear reduction has allowed the fans to become larger in diameter. The fan rotor blades should be lightweight, despite the increasing size. In addition, there are requirements that a fan blade be relatively strong, as it must be able to survive certain levels of impact from foreign objects. As an example, birds may sometimes impact a fan blade in a gas turbine engine, and the blades must survive the impact.
Fan blades designs utilizing hollow constructions have recently been considered.