A Study on Bird Impact Damages on Shrouded Fan Blades of an Aero-Engine

Aero-engine fan blades are the critical components that are vulnerable to Foreign Object Damage (FOD) such as bird impact. The thrust loss due to bird impact can affect engine core function, resulting in catastrophic failure. The fan blades should be designed to have adequate resistance to bird impact. The present paper focuses on numerical evaluation of bird impact response on shrouded and un-shrouded rotating set of fan blades using three dimensional computational methodology. The impact response is compared between shrouded and un-shrouded blades in terms of deformation, von-Mises stress, plastic strain, and energy absorbed. Numerical analysis results indicate that the shrouded fan blade absorbs 35 % more energy compared to un-shrouded blade. Deformation damage at impact location of shrouded blade is lesser compared to un-shrouded blade. The maximum plastic strain observed on shrouded blade due to bird impact is also 50 % lesser than the un-shrouded blade. The study suggests that the shrouded fan blades provide better impact resistance characteristics to bird impact compared to un-shrouded fan blades.