Optimization design of a reversible pump-turbine runner with high efficiency and stability

Frequent changes between pump and turbine operations pose significant challenges in the design of pump turbine runners with high efficiency and stability. In this study, a multiobjective optimization design system, including a 3D inverse design, computational fluid dynamics, design of experiment, response surface methodology, and multiobjective genetic algorithm, is introduced and applied to the design of a middle-high-head pump turbine runner. The key parameters in the design, including the blade loading, the blade lean at the high-pressure side of the runner, and the meridional channel shape, were selected as the optimized parameters. Two runners, one with a large positive blade lean and another with a large negative blade lean, were selected for further numerical investigations and measurements. Model tests show that both runners have good power performances. The runner with a negative blade lean has better stability than the runner with a positive blade lean. (C) 2015 Elsevier Ltd. All rights reserved.