The availability of the energy has changed humanity over last centuries. first types used by were renewable energies: biomass, wind, and water. But, for two centuries, fossil fuels have been protagonists world consumption. However, recently there an awareness great dependence on a finite resource, geographically concentrated in few countries, which addition to degrading environment, is subject ...

Abstract The parameters such as oil density and bulk elastic modulus of hydraulic in steam turbine electro-hydraulic servo system vary with ambient temperature, pressure, other factors, there are unmodeled dynamics the system, so obtaining a satisfactory following effect is challenging task for servo(EHS) system. According to principle force balance flow continuity, mathematical model bilateral...

Francis turbines can experience critical instabilities at high load operating points, limiting their maximum power output. The swirling flow developed in the draft tube produces a cavitating axisymmetric volume, acting as an internal energy source leading to a self-excited surge phenomenon. The pulsation of the vortex rope corresponds to one of the eigenfrequencies of the hydraulic system. Effo...

Abstract This article presents a comparative analysis of flow characteristics behind hydraulic turbine runner in air and water. Swirling with precessing vortex core (PVC) was investigated using laser Doppler anemometer pressure pulsation sensors. The experiments were conducted on aerodynamic hydrodynamic test rigs over wide range operating conditions. Part-load modes operation the Fourier trans...