Robust design of turbine blades against manufacturing variability

Turbine blade life is central to the integrity of the aircraft engine. Manufacturing variability may lead to variations in the expected life and performance of turbine blades. It becomes important therefore to understand these variations and seek new designs that are robust to manufacturing variability. The present work proposes a methodology that employs Free Form Deformation in conjunction with optimisation to generate realistic 3D representations of the manufactured blades using limited measurements available per blade. Lifing estimations on the perturbed geometries show a reduction of around 1.7% in mean life relative to the designed life with a maximum relative reduction of around 3.7%. Following this, the proposed methodology is employed for robust design studies resulting in a better turbine blade design. This design indicates an improvement of around 2% in the designed life, around 3% improvement in mean life and approximately 57% reduction in blade life variability as compared to the current turbine blade design.