Experimental study of the overall cooling effectiveness of f-type impinging-film cooling configurations

Impinging film cooling as an efficient design of the cooling structure can be used in the combustor of high-performance aero-engines. In this work, experiments were implemented to investigate the overall cooling effectiveness of the F-type impinging-film structure concerning various geometric parameters and flowing factors. Effects of blowing ratio M , jet-hole diameter d , jet-to plate pitch z , and jet holes spacing y on the overall cooling effectiveness are investigated. Nine configurations with different non-dimensional impinging height Z_n (1.5 ≤ Z_n ≤3.2), non-dimensional jet hole spacing Y_n (1.96 ≤ Y_n ≤3.5), and jet hole diameter d ( d=1,1.2,1.6mm ) are studied. Experiment results show that the overall cooling effectiveness η increases with the increase of blowing ratios M , and this tendency becomes weaker as the blowing ratio M exceeds 1.31. The non-dimensional impinging height Z_n =1.5 makes a high cooling performance at all blowing ratios M . The area-averaged cooling effectiveness of Z_n =1.5 is 2.1