Multiple segment parallel compressor program for analyzing circumferential total pressure distortion effects on compressor surge margin and performance

Aircraft turbine engine compression system response to inlet total pressure distortion may result in reduced engine stability margin and in some cases a complete loss of stable engine operation. The engine and compression system performance characteristics can also be influenced.

A computer model, based on the multiple segment parallel compressor technique has been written as part of this research investigation to predict the engine compression system response to various types of circumferential total pressure distortion. The computer model was compared to actual compressor data from three different engines with various types of circumferential distortion profiles. The Allison XC-1 Lift Engine, the General Electric J85-13, and the Pratt & Whitney F100 (3) were the three compression systems used in the comparison.

Comparison of the computer model results against experimental data yielded encouraging results with stability margin (surge margin) predicted to within a couple percent. The computer model is currently unable to predict the trend of increasing surge margin as circumferential extent decreases. The compressor performance predictions were significantly less than the experimental data. The correct distorted performance trend of decreased corrected airflow and increased pressure ratio were predicted.