A Stage-by-Stage Dual-Spool Compression System Modeling Technique

Abstract

Mathematical compressor models are major tools used in resolving engine problems and evaluating the influence of compressor modifications on performance and stability. This paper discusses the development of a one-dimensional, time-dependent, dual-spool, stage-by-stage compression system mathematical model and its application to a current compression system. The dual-spool model was constructed by extending a current single-spool modeling technique to include dual-spool compression systems. To improve the numerical stability characteristics of the compressor modeling technique, the dual-spool model was formulated using MacCormack’s explicit differencing scheme and a method of characteristics boundary treatment. The dual-spool model was applied to a current compression system, and several types of planar destabilizing disturbances were studied to determine their effect on compression system stability. Model predictions were validated against experimental data whenever possible.