The lower atmosphere is known to be relatively more concentrated with airborne pollutant. Short-range aircrafts are particularly more affected due to the altitude they operate, making them more susceptible to compressor fouling degradation. This usually leads to the demand for more fuel that increases the emissions, to make up for the reduction in the thrust. Compressor fouling is therefore a concern for aircraft operators due to increasing fuel cost and emission-based landing fees which impact the direct operating costs of an aircraft.
Highlighting the performance and economic benefits of compressor washing are the key aims of this study. An economic model is developed and the benefit is calculated for different wash intervals, which are based on the usual aircraft checks. The clean and fouled engine performance is simulated, indicating the impact of compressor fouling degradation on the twin-spool engine model. To emphasise the benefit of compressor washing, the degraded engine is compared to its new condition after washing. It was observed that it is impossible to fully recover the performance of a fouled compressor by an on-wing compressor wash.
This study concludes that compressor washing has a significant improvement on engine performance, as well as cost benefit in monetary terms. The results also suggest that compressor washing can reduce the unwanted thrust loss and exhaust gas temperature increase due to fouling, by half. A gross recovery of almost £75,000 per year for a short-range engine is shown to be achievable with a marginal increase of the total washing cost.