Abstract The precessing vortex core (PVC), also known as rope, in a draft tube of Francis-99 hydro turbine is investigated. goal to increase our comprehension the root PVC order attenuate or suppress PVC, thus extending stable operational range below best efficiency point at part load conditions. Unsteady Reynolds-averaged Navier– Stokes simulations are conducted and used basis for all analyses...

Several methodologies have successfully described the runner blade shape as a set of discrete sections joining hub and shroud, defined by 3D geometrical forms considerable complexity. This task requires an appropriate parametric approach for its accurate reconstruction. Among them, piecewise Bernstein polynomials been used to create parametrizations twisted blades extracting some cross-sectiona...

Abstract The stability of the electricity grid will be disrupted by massive integration new renewable energies. Hydropower plants have a major role to play in this transformation market increasing their operational flexibility and ability provide ancillary services. However, may lead an accelerated degradation mechanical components. By changing turbine operating point far from best efficiency o...