Design of Francis turbine runners based on a surrogate model approach

Based on a new parametric definition of the Francis turbine runner blade, in combination with extensive and systematic CFD and FEM simulations, the authors' company is now implementing a surrogate model approach in its Francis turbine design process. This makes it possible to evaluate a large range of factors simultaneously, tuning the surrogate models to mimic the Francis turbine runner responses. The surrogate model is also a useful way to gain insight into the global behaviour of various runner profiles. A complete new design series of Common Blade™ Francis runners are under development based on this approach.