Analysis on Characteristics of Mode Transition Performance of Variable Cycle Engine with FLADE

The variable cycle engine (VCE) with FLADE (Fan on Blade) is one of the research hotspots for future military and civil aircraft power device, which shows outstanding performance advantages. For evaluating its performance, the method for FLADE component simulation and the steady-state performance simulation model for the double bypass VCE with FLADE are developed. The transient performance simulation model for VCE is also established, which considered the effects of the polar moment of inertia and the component volumes during the dynamic equation constructing. The transient performance at mode transition state of the FLADE VCE between double bypass mode and single bypass mode is discussed, and the influence of geometric parameters on the mode transition state of FLADE VCE is deeply analyzed. It can be concluded that the mode transition characteristic of the double bypass FLADE VCE is only related to the angle of inlet guide vane of FLADE and the area of the FLADE nozzle, and both should be enlarged or closed at the same time. The state of FLADE is on or off which has small impact on airflow of fan bypass and core engine.