Abstract: States values of volumes and rotors calculated by volume dynamics and rotor dynamics provided input data for map-interpolation and calculation of compressors and turbines. So the computation process of the variable cycle engine (VCE) numerical simulation model did not need guess values and iterative process. The model also simulated the variable geometries. Mode conversion from double bypass to single bypass was simulated with this model. Then the engine characteristics of these two modes were calculated with altitude，velocity and throttling. The results of mode conversion at the flight condition with a height of 0 km and a Mach number of 0 show that the thrust increased 16.823% and the specific fuel consumption (SFC) increased 15.163% while the bypass ratio (BPR) changed from 0.700 to 0.307.

Key words: Variable cycle engine；Volume dynamics；Rotor dynamics；Numerical simulation；Mode conversion

摘要： 使用容积动态与转子动态来计算容积与转子的状态量，为压气机及涡轮的特性图插值与计算过程提供输入数据，使得变循环发动机数值仿真的运算过程无需猜值与迭代；并给出了对变循环发动机的可调几何的仿真方法。使用此模型仿真了从双外涵模式向单外涵模式切换的过程以及这两种模式下变循环发动机的高度、速度、节流特性。在高度0km且马赫数为0的大气环境下模式转换的仿真结果显示，变循环发动机涵道比由0.700下降到0.307，单外涵模式与双外涵模式相比推力提高了16.823%，单位燃油消耗率增加了15.163%。

关键词: 变循环发动机；容积动态；转子动态；数值仿真；模式切换