The effect of additive ‘depositional’ reprofiling of compressor blade leading edges on engine performance

A common problem for gas turbine engines after ingesting atmospheric dust is compressor fouling, where small particles adhere to component surfaces. By sampling components from both a test engine and a service engine, deposits that are hard and sintered were observed to have formed on the leading edges of compressor blades and stators reprofiling their leading edge geometry. Sectioning of the components showed that the deposits consist of layers of different chemical compositions and that new minerals have crystallized within the deposits. The change in geometry caused by the deposits suggests that they negatively affect the operating incidence range, surface pressure distribution, and profile losses from the design intent of the original component, changing the compressor working line and reducing surge margin, efficiency, and pressure ratio.