Investigation of the Film-Cooling Performance of 2.5D Braided Ceramic Matrix Composite Plates with Preformed Hole

• Published in: Aerospace 2021-04, Vol.8 (4), p.116
• Main Authors: Zhao, Chenwei, Tu, Zecan, Mao, Junkui
• Format: Article
• Language: English
• Subjects: 2.5D braided composite; anisotropic thermal conductivity; Braided composites; Braiding; Ceramic matrix composites; Composite materials; Composite structures; Cooling; Extrusion; film cooling; Heat conductivity; Heat resistance; Heat transfer; Investigations; Manufacturing; Mathematical models; Mechanical properties; Numerical models; Oxidation; preformed hole; R&D; Research & development; Stress concentration; Temperature; Temperature gradients; Yarn
• ISSN: 2226-4310; 2226-4310
• DOI: 10.3390/aerospace8040116

The film-cooling performance of a 2.5D braided ceramic matrix composite (CMC) plate with preformed holes was numerically studied. Four numerical models containing braided structures were established: one model with film-cooling holes preformed through fiber extrusion deformation (EP-Hole), one model with film-cooling holes directly woven through fibers (WP-Hole), and two models with directly drilled holes (DP-Hole1,2). Besides, the influence of the ratio between the equivalent thermal conductivities on the axial and radial directions of fiber Kr was investigated. The results show that the preformed holes have better performance in controlling the thermal gradient with the increase of Kr. The maximum thermal gradient around the DP-Hole is significantly higher than that of the WP-Hole and EP-Hole, and the maximum relative variation reaches 123.3%. With Kr increasing from 3.32 to 13.05, the overall cooling effectiveness on the hot-side wall decreases for all models, by about 10%. Compared with the traditional drill method, the new preformed film-cooling hole studied in this paper can reduce the temperature and the thermal gradient in the region around the holes.