Abstract This paper presents preliminary results of an experimental study on the occurrence and development upper part-load instability in a reduced-scale Francis turbine. The includes draft tube pressure measurements, high-speed flow visualization, particle image velocimetry. Our reveal that for operating point within range (70 to 85 % nominal discharge), vortex rope has circular cross section...

Abstract In this paper, we investigate the formation of Rotating Vortex Rope (RVR) using scale-resolving methods, SAS and Wall-Modeled LES (WMLES). We compare results from these simulation methods with experimental data Francis-99 workshop. This comparison shows that general features RVR can be captured both methods. However, WMLES would lead to a better quantitative agreement between velocity ...

The purpose of this paper is to estimate hydroelectric turbine runner modal characteristics from experimental measurements coming asynchronous regimes. This achieved by investigating resonances generated the interaction a structural mode with harmonics rotating speed. Resonances are extracted using order tracking and processed Fast Bayesian algorithm in an ambient manner parameters related unce...