Research of variable cycle engine modeling techniques

The component level model of variable cycle engine (VCE) was built based on analysis of engine structure, and with a reference to the modeling method of two-spool-turbofan engine. The model of fan was developed with separated characteristic of fan tip and hub sections. The model of core drive fan stage(CDFS) model was built to work under single bypass mode and double bypass mode. According to the specialty of VCE, the static and dynamic co-working equations were set up, reflecting the variation of variable geometry components. The results of numerical simulation indicate that the VCE model enables switching of the working modes. In double bypass mode at low altitude and low mach number, it represents higher thrust and lower specific fuel consumption just as turbofan engine, and in single bypass mode at high altitude and high mach number, it shows higher thrust and lower specific fuel consumption just as turbojet engine. The performance variation in simulation accords with the specialty of VCE, so the modeling method of VCE proposed is feasible.