Predicting the Temporal Progression of Aircraft Engine Compressor Performance Deterioration due to Particle Deposition

Abstract

Aircraft engine performance deterioration due to particle deposition on compressor blading and end walls gradually progresses with increasing time of operation. Deposition effects can be mitigated by on-wing maintenance actions. Application of condition based maintenance strategies in order to minimize operating costs requires high-grade physical deterioration models. In previous work, a model and experimental setup were developed to quantify both magnitudes and timescales of deposition effects on blade row performance as a function of engine operating time. The model and experimental data published therein were now used to predict the deteriorated performance of aircraft engine high-pressure compressors. A given procedure to analytically derive stage characteristics from blade row data was altered in such a way as to account for stage performance deterioration through a set of modifiers. These time-dependent modifiers were calculated from the blade row performance deterioration model. As an example of application, the stage characteristics of the NASA Energy Efficient Engine high-pressure compressor were derived from published data. The stage characteristics were gradually modified according to the aforementioned approach. A stage-stacking procedure was then used to calculate the full map of the deteriorated compressor. Results showed a gradually progressing shift of compressor speed lines to lower mass flows and pressure ratios as well as a collapsing of efficiency isolines. The design point of the new engine and the point of maximum efficiency no longer coincide. Maximum efficiency decreased. The methodology presented enables aircraft engine operators to predict individual engine on-wing recoverable performance deterioration to optimize maintenance scheduling and, thus, reduce operating costs.