The sensibility analysis of the gap ratio was investigated on the cooling effect of the rotating cavity with intent of ensuring safety of a turbine disk

one of the life-limited parts in the propulsion system.The cooling effect was evaluated by fluid-structure-interaction numerical method according to resistance evaluation

heat transfer evaluation and stress distribution evaluation.The results show that the gap ratio has a great effect on heat transfer and temperature distribution of the rotating disk.Furthermore

the thermal stress of the rotating disk related to the temperature gradient can be affected.As the rising of the gap ratio

the frictional windage of the rotating cavity has not changed

heat transfer of the windward of the disk takes on up-down tendency

and the stress level and the maximum value enlarged.Therefore

change of the gap ratio has an effect on the failure probability of the turbine disk from two aspects:the material affordability and the working stress.