Some refinements and applications of the multi-stage axial flow compressor time-dependent mathematical modeling technique

The overall objective of the work described herein was to construct a validated mathematical model of the high-pressure (HP) compressor of the TF41-A-1 turbofan engine, and, in so doing, to provide a new analysis tool with which to assess the influence of external disturbances and compressor modifications on performance and stability. The objectives were accomplished through the development of both a one-dimensional, steady-state TF41-A-1 compressor mathematical model for the stability assessment with undisturbed flow, and a three-dimensional, time-dependent TF41-A-1 compressor mathematical model for analysis of distorted inflows, transient and dynamic disturbances. Example problems with comparisons to experimental results are presented for both models. Example problems using the one-dimensional, steady-state model consisted of determination of the steady-state stability limits (surge lines) with undisturbed flow for three distinct inlet guide vane (IGV) schedules. Example problems using the three-dimensional, time-dependent model included determination of the stability limit reduction caused by pure radial inlet pressure distortion, pure circumferential inlet pressure distortion, and pure circumferential inlet temperature distortion. Also, the effects of rapid upward ramps of inlet temperature on compressor stability were investigated.

For both models the comparisons made with experimental results reveal that the TF41-A-1 compressor models predict the compressor stability limits with reasonable accuracy.