Optimization of crescent-shaped block downstream a row of cylindrical holes to enhance film cooling effectiveness

The present work has been conducted to find the optimial geometrical parameter combination for the crescent-shaped block downstream of a row of cylindrical holes. The effects of geometrical parameters on the cooling performance are evaluated from the results of a parametric study. The maximum area-averaged cooling effectiveness is pursued using the genetic algorithm combined with the CFD method at two blowing ratios of 0.5 and 1.5. Compared with the reference block, the corresponding optimal block demonstrates an increase in area-average cooling effectiveness by 6.2% at a blowing ratio of 0.5 and 98.3% at a blowing ratio of 1.5, respectively. The enhancement in the cooling performance mainly results from the improvement in the streamwise coolant coverage and the lateral coolant coverage at blowing ratios of 0.5 and 1.5, respectively.