A Design System for Erosion Tolerant Helicopter Engines

The engine degradation due to sand or dust ingestion becomes more serious with high specific flow advanced technology compressors, which are prone to erosion due to increased tip speed, reduced blade thickness, and close running clearance. This paper presents a design system for inlet particle separators to remove the solid particles from contaminated air and a compressor erosion computation technique to assess the erosion damage to compressor vanes and blades. This is developed as part of the axial flow compressor design system, so that erosion effect can be included in the compressor design process. The erosion computation code combines fully three-dimensional particle trajectory calculations with statistical methods to obtain erosion pattern in blades using basic material erosion models. The code was used to compute the erosion damage of the first-stage rotor of an axial flow compressor. The computed erosion pattern compares very well with the pattern obtained during sand ingestion rig test.