Study of the effect of particle deposition characteristics and blockage of film holes on the cooling efficiency

Based on improved depositional modeling and dynamic mesh techniques, this paper researched the deposition morphology of particles around film holes (cylindrical holes, fan-shaped holes, and slit holes) and the effect of hole blockage on the cooling characteristics of the film holes. The results suggest that the deposition is mainly distributed in the area between and downstream of the film holes where the cooling jet does not cover well. Most deposits were found downstream of cylindrical holes. At a high blow ratio, there is less deposition downstream of slit holes than fan-shape holes. However, at a low blow ratio, the results were the opposite. It has been found that large-diameter particles can easily invade the interior of the film holes. At different blowing ratios, the trailing edges of the film holes showed varying degrees of blockage, and the blockage structure diminished with the increase in the blowing ratio. In addition, based on the degree of grid deformation in the film hole area, a blockage model in the hole under different blowing ratios was constructed, and the change in cooling efficiency was when three types of holes were blocked. After the blockage, the fan-shaped hole is least affected by the blockage, while the cylindrical hole is most affected by the blockage. And the average surface cooling efficiency of the slit holes has the largest increase as the blowing ratio rise.