In order to study the effects of hole patterns on absolute cooling efficiency of flat gas film

the finite volume method was adopted to discretize the control equations

on the basis of SST k-ωturbulence model and Simple algorithm.Numerical simulation was performed on holes with three shapes

sister hole without groove

groove cylindrical hole and groove sister hole.Under conditions with simulated blowing ratios of 0.5

1.0

1.5and 2.0

the velocity distribution in cross section where X/D=4was obtained

as well as the cooling efficiency of different holes.The results show that

with an increase in blowing ratio

the cooling efficiency of the above three holes decreases.The average cooling efficiency and coverage area of the groove sister hole is the optimum at low blowing ratio(M=0.5)

while that of the groove cylindrical hole is the best at high blowing ratio(M=2.0).