A mathematical model is developed for simulating transient performance of the turbofan engine
in which the transient heat transfer between the components and airflow
tip clearance and components efficiency changes caused by heat transfer are analyzed.The calculated result shows that there are significant influences of heat transfer on the engine's transient performance
and the component efficiency loss caused by tip clearance changes can not be ignored.The simulation accuracy can be improved by above model for the turbofan engine transient performance.