Optimum design of the chute-flip bucket system using evolutionary algorithms considering conflicts between decision-makers

Various stakeholders with conflicting preferences are involved in the design of the chute-flip bucket system. In this research, a feasible methodology is proposed for optimizing the design of the chute-flip bucket system that considers the conflicting preferences of various stakeholders. Accordingly, the FLOW-3D® model was developed and calibrated and was used to simulate the hydraulic behavior of the chute-flip bucket system. This model was then run for different geometric scenarios, and the resulting database was used to train an MLP-ANN meta-model. Given the utility functions of different stakeholders, the meta-model was coupled with the NSGA-II and NSGA-III optimization models. Results show that the latter performed better. Lastly, to obtain the best design alternative and a compromise among the stakeholders, Pareto optimal solutions were examined using Social Choice Rules and the Unanimity Fallback Bargaining method. The application of the proposed method in Jareh Dam, Iran, showed that the optimum scenario (selected by the Unanimity Fallback Bargaining method) enhance the energy dissipation and cavitation index by about 12.5 and 9.5%, respectively, while compared to the current chute-flip bucket system the cost remained almost constant. The results provide useful knowledge regarding the robust design of hydraulic structures, taking into account the conflicting objectives of different stakeholders.