With an unsteady heat transfer model

an assumption of neglecting the effects of heat transfer on the work of rotating components and a simplified heat transfer model of cooled turbine were put forward

and a transient engine model was built by taking the heat soakage into account. The numerical simulation results of a turbofan engine transient performance showed that

the main effects of heat transfer soakage on the engine performance were attributable to the response delay in each component

which was more serious in low pressure components. The thermal time constants of the compressor were smaller than those of the turbine. For the thermal time constants of the same component

the blade was the smallest

the hub was larger

and the casing was the largest.