Effects of hole configuration on film cooling effectiveness and particle deposition on curved surfaces in gas turbines

In this paper, effects of four different hole configurations on film cooling performance and particle deposition are investigated numerically on a curved surface. The RNG k-ε turbulence model is used, and the discrete phase model is developed by user-defined functions. The particle deposition on the curved surface is analyzed by calculated results of capture and impact efficiencies. Results show that the average film cooling effectiveness for the combined hole, the fan-shaped hole and the round-to-slot hole are 69.8%, 60.3% and 32.0% higher than that for the traditional cylindrical hole at the blowing ratio 1.2. In addition, an inclination angle of 30-45° has a significant effect on the average film cooling effectiveness except for the round-to-slot hole. The impact and capture efficiencies increase first and then decrease with the increase of the particle size at the blowing ratio in the range of 0.3 to 0.9. For 1 μm particles, the round-to-slot hole has the maximum values of the impact and capture efficiencies. It is also found that for 1 μm particles, when the inclination angle is 30°, the lowest impact and capture efficiencies are reached for the fan-shaped hole and the round-to-slot hole.