The friction characteristics of a rotor-stator system with centre inflow of cooling air for two sealing geometry were experimentally studied.The experimental results show that:the friction coefficient will decline with the increasing ratio of sealing clearance and mass flow coefficient

and increase with the rotating Reynolds number.For the stationary case

the ratio of sealing clearance affects the friction coefficient much obviously than the mass flow coefficient;for the rotating case

the ratio of sealing clearance affects the friction coefficient less obviously than the mass flow coefficient and the rotating Reynolds number.