Genetic algorithm optimization of film cooling effectiveness over a rotating blade

Shape optimization of a laterally diffused hole has been performed to enhance the film cooling effectiveness under rotating conditions. The blade rotates at three different speeds of 0, 300 and 500 rpm. The shape of the hole is defined by three geometric design variables, namely, the injection angle of the hole, the lateral expansion angle and the ratio of the length to the diameter of the hole. The numerical results for the film-cooling effectiveness were validated by a comparison with the available experimental data. More than sixty designs within the design spaces are selected and numerically simulated to calculate the objective function at three rotational speeds. The objective function, which is defined as the area averaged film-cooling effectiveness, is approximated using curve fitting method (CFM) to search for the optimal point. The optimizations are carried out for three different rotational speed using genetic algorithm (GA) method. The film-cooling effectiveness has been successfully improved with the CFM-GA optimization at three rotational speeds as compared to the reference cylindrical hole.