Analysis of the matching of fans, CDFS and HPC in a DBE compression system

摘要

Flexibly variable compression system is a major source of double bypass engine's (DBE's) performance advantages.Multi-bypass and area-variable features of the compression system disabled the traditional design tools either by function defects or by time consuming.So a particularly developed throughflow method was adopt here to analyze a double bypass compression system, which consists of a fan, a core driven fan stage(CDFS), a five-stage high performance compressor(HPC) and two bypasses.Calibration of the method was performed at first with a mature CFD tool.Baseline matching state of the compression system was investigated with the calibrated throughflow method, which shows spanwise mismatching led to a decline in performance and stable work range of CDFS and HPC.Exploring of first and second bypass throttling characteristics indicated aggravations of those mismatches.For HPC, the inlet distortions in spanwise merely affect the first stage remarkably.Control rules of forward and rearward VABI determine the variation tendency of matching correlations while the baseline matching conditions set the performance level.The two aspects should be synthetically evaluated in design considerations.