Aerodynamic performance investigation of a compact compression system for turbofan engine

The performance of a compact compression system with fan-bypass-core compressor configuration was investigated numerically in this paper. The throttling methodology for accessing performance of fan-bypass-core compression system and its implementation during the numerical simulation was discussed. The calculated design speed performance of fan and high pressure compressor (HPC) shows that the design targets are achieved for mass flow, total pressure ratio and efficiency, while the stall margin of fan is only 7.8%, lower than the required value. Analysis of the flow field evolution shows that, during core nozzle throttling, the system instability is initiated in the exit stage of HPC; during bypass nozzle throttling, however, the large extent blockage, which is caused by the interaction of rotor tip vortex and passage shock, may contribute to the instability of the compression system.