Multi-Objective Optimization of the Collection Device Shape of an Axial Flow Hydraulic Turbine with a Collection Device

Abstract

In this study, a multi-objective optimization design method, combining a design of experiments single phase flow analysis, response surface method and a multi-objective optimization method was developed to optimize the collection device shape of an axial flow hydraulic turbine with a collection device to achieve high power and low axial thrust. In addition, the effectiveness of this design method was validated through verification experiments in an open channel with shallow water depth and multiphase flow analysis considering a free surface, and the differences from the single phase flow analysis results were also discussed. As a result, the optimized collection device obtained by this design method showed the same axial thrust coefficient and improved power coefficient compared with the original collection device in the single phase flow analysis. In the open channel, the power coefficient of the optimized collection device was significantly higher than that of the original collection device but unlike the results of the single phase flow analysis, the axial thrust coefficient of the diffuser was significantly increased, resulting in a significant increase in total axial thrust coefficient.