Response surface-based shape optimization of a Francis draft tube

Purpose - This paper aims to develop an efficient and accurate numerical method that can be used in the design process of the waterways in a hydropower plant. Design/methodology/approach - A range of recently published (2002-2006) works, which aim to form the basis of a shape optimization tool for flow design and to increase the knowledge within the field of computational fluid dynamics (CFD) and surrogate-based optimization techniques. Findings - Provides information about how crude the optimization method can be regarding, for example, the design variables, the numerical noise and the multi objectives, etc. Research limitations/implications - It does not give a detailed interpretation of the flow behaviour due to the lack of validation data. Practical implications - A very useful flow design methodology that can be used in both academy and industry. Originality/value - Shape optimization of hydraulic turbine draft tubes with aid of CFD and numerical optimization techniques has not been performed until recently due to the high CPU requirements on CFD simulations. The paper investigates the possibilities of using the global optimization algorithm response surface methodology in the design process of a full scale hydraulic turbine draft tube.