Abstract
A design optimization system for Francis turbine was developed. The system consists of design program and CFD solver. Flow passage shapes are optimized automatically by using the system with Muiti-Objective Genetic Algorithm (MOGA). In this study, the system was applied to a high specific speed Francis turbine (nsp=250m-kW). The runner profile and the draft tube shape were optimized to decrease hydraulic losses. As the results , it was shown that the turbine efficiency was improved in wide operating range, furthermore, the height of draft tube was reduced with the hydraulic performance kept.
