Film cooling performance and flow structure of single-hole and double-holes with swirling jet

This paper presents the results of a numerical study of the effects of swirling flow in coolant jets on film cooling performance. Some combined-hole designs with swirling coolant flow entering the delivery hole are proposed and analyzed. Adiabatic film cooling effectiveness values for cases with various blowing ratios are compared. Detailed flow structures and underlying mechanisms are discussed. The results show that film cooling effectiveness is improved with jet swirl at high blowing ratios, and that swirl strength has significant influence on film cooling performance. Combined-hole designs can further improve film cooling performance using swirling jets due to mixing of coolant flows and interaction of vortices. The largest improvements of area-averaged film cooling effectiveness for a single-hole swirl case and a combined-hole swirl case over corresponding non-swirling case results are 157% and 173%, respectively.(c) 2021 Chinese Society of Aeronautics and Astronautics. Production and hosting by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This paper presents the results of a numerical study on the effects of swirling flow in coolant jets on film cooling performance. The study proposes and analyzes combined-hole designs with swirling coolant flow, and compares the film cooling effectiveness values for cases with different blowing ratios. The detailed flow structures and underlying mechanisms are discussed. The results indicate that jet swirl improves film cooling effectiveness at high blowing ratios, and swirl strength significantly influences film cooling performance. Combined-hole designs further enhance film cooling performance through coolant flow mixing and vortex interaction.