Comparison of Ingestion of Different Size Hard and Soft Bodies Into a Representative Fan Assembly Model

Abstract

Foreign matter ingestion into a jet engine is a significant hazard to the safety of aircraft. While soft body ingestions (i.e., bird or ice ingestions) have been extensively researched, the threat posed by uncrewed aircraft systems (UASs) is a more recent concern due to their recent rise in popularity and has not been thoroughly studied. To better understand the damage caused by UAS ingestions, it is crucial to examine the resulting ingestion damage in comparison to birds of similar mass. This analysis is an essential initial step in determining how previous knowledge regarding soft body ingestions can relate to this new threat. To properly analyze these ingestions, development of a model that accurately represents a fan assembly is essential. This model should include a fan, as well as representative boundary conditions for the ingestion, such as blade retention systems, nose cone, casing, and shaft. Items that are analyzed during the ingestion include the overall damage to the fan blades, average and peak forces imparted on the retention systems, impact loads with the casing, and transient loads due to impact on the shaft. The foreign object models used were experimentally validated at their nominal sizes to increase confidence in the results. Comparison of the effects of ingestion of UAS and birds of difference mass into the representative fan model are presented and discussed to gain a better understanding of the differences between soft and hard body ingestion.