By taking the rotor blades of a high pressure gas turbine as the research object

the leakage vortices and heat transfer coefficients of the squealer tip were numerically simulated under conditions with Reynolds number of 9×104 and attack angle of-5

0°and 5°

to investigate the effects of attack angle and endwall slippage on the flow and heat transfer in the blade tip gap.Moreover

the simulation results were verified experimentally.The results show that

the calculated pressure coefficients are consistent with the experimental data

implying the numerical simulation results were valid.When the endwall are not slipping

the vortices induced by the leaking from the leading edge neighboring to the pressure side developed to both the suction side and the trailing edge.The heat transfer coefficients on the tip decreased along the camber curvature from the leading edge.The slippage of the endwall weakened the leakage vortices and the fluid of the leakage flowed uniformly from the pressure side to the suction side.The heat transfer coefficients on the tip decreased along the direction normal to the chord.The slippage of the endwall decreased the velocity magnitude of the leakage

but the averaged heat transfer coefficients increasd slightly.The maximum value of the heat transfer coefficients on the tip decreased by 7.5%

8.1%

and 19.2% by the slippage of the endwall with three attack angles

respectively.The maximum values of heat transfer coefficients on the tip both with and without the slippage decreased by 14.9% and 22.4%

respectively

and the averaged heat transfer coefficients both with and without the slippage decreased by 11.8% when the attack angles changed from-5°to 5°.