Patent ID: 9650914
Date: 2017-05-16
CPC Classifications: F01D,F05D

Claim:
1. A turbine rotor for a gas turbine engine, the turbine rotor comprising: a turbine disk having a rupture rotational speed at which the turbine disk ruptures; a plurality of blades receivable in the turbine disk each having an airfoil, the airfoil having a pressure side and a suction side, the airfoil having a span direction and a chord-wise direction, the airfoil extending from an inner end to an outer end in the span direction and from a leading edge to a trailing edge in the chord-wise direction, the airfoil having an airfoil span on a pressure line being a projection of a stacking line onto the pressure side, the airfoil having a plurality of chords extending between the leading edge and the trailing edge; and a generally round dimple on the pressure side of the airfoil, the dimple being contained in an area extending on the stacking line between 0% and 23% of the airfoil span from the inner end, and in the chord-wise direction between 0% of a first chord and 82% of a second chord from the leading edge, the dimple corresponding to material removed from the airfoil, the material removed being greater than 15% and up to a maximum of 39% of un-dimpled nominal airfoil thickness of the airfoil, the dimple being configured to initiate fracture at the dimple of each one of the plurality of blades at a predetermined rotational speed being less than the rupture rotational speed of the turbine disk.