In order to investigate the cooling characteristics of the trailing edge on turbine blade

numerical simulation method was used to study the film cooling effectiveness at the blowing ratios of 0.5

0.8

1.0 and 1.5 for the three-dimensional split cooling model of the backward-facing step. The results show that

in the backwardfacing step area

the film cooling effectiveness in the downstream of the split slot is 10.9%～39.1% higher than that of the ribs at small blowing ratio of 0.5 and 53.5%～56.0% higher at big blowing ratio of 1.5. The higher the blowing ratio is

the faster the film cooling effectiveness of the backward-facing step decreases along the gas flow direction

and the lower the film cooling effectiveness of the tail of backward-facing step decreases along the direction of the semi-cylindrical circumference. On the downstream of the tail ribs of backward-facing step

the film cooling effectiveness of blowing ratio of 0.8 and 1.0 are about 7.0% higher than that of 0.5 and 1.5. The backward-facing step tail is the weak part of the film cooling

and its area-weighted average film cooling effectiveness is 37.0%～39.0% lower than that of the backward-facing step. When the blowing ratio is 0.8 and 1.0

the area-weighted average film cooling effectiveness of the backward-facing step and its tail is the highest

which is 9.0%～11.0% higher than that of the blowing ratio of 0.5

and 3.0%～6.0% higher than that of the blowing ratio of 1.5.