Experimental and numerical investigation of film cooling effectiveness for rectangular injection holes

摘要

Purpose - To investigate the film cooling effectiveness in a flat plate with a single row of rectangular injection holes. Design/methodology/approach - Three injection holes in model are in a single row. The holes are rectangular cross section and they are 9 × 6.5 mm. The injection holes are inclined at 30° along the mainstream direction. The blowing ratios are from 0.5 to 2.0. The experiments and their computational models are established to investigate its effects at the 330 and 335 and 340 K injection temperatures and the different blowing ratios. Findings - Results show that the blowing ratio and injection temperature and momentum flux ratio affect the film cooling effectiveness and to provide a good film cooling performance in both mainstream and lateral direction a suitable blowing ratio should be selected. In this study, the highest effectiveness is determined at a blowing ratio of 0.5. Further increasing this ratio results in reverse effect on the film cooling effectiveness. Originality/value - It is the fist time the film cooling effectiveness is compared at the rectangular injection holes as experimental and numerical.