Unsteady numerical simulation of suction side leading edge cavitation in a Francis turbine runner
Document typeConference report
PublisherShanghai University Press
Rights accessOpen Access
Cavitation appearance within the runner of the water turbines is a common problem that induces vibrations and provokes the erosion of the blades. Although many investigations have been carried out in simple configurations such as 2D and 3D hydrofoils in cavitation tunnels, few works have been done to simulate the cavitation dynamic behavior in actual turbine geometries. In this paper, the unsteady numerical simulation of suction side leading edge cavitation has been carried out for the GAMM Francis runner. For that, the two-phase model available in ANSYS¿ CFX and the Shear Stress Transport (SST) turbulence model have been used. A sensitivity analysis of various model parameters has been done and the results have been validated with experimental values obtained in a reduced scale model test utility at the best efficiency point. Special attention has been given to determine if a shedding process also exists and to understand the main hydrodynamic mechanisms involved. In conclusion, the instability of the leading edge cavitation seems to be mainly caused by field pressure perturbations originating from the guide vanes or the draft tube.
CitationChen, J.; Escaler, X. Unsteady numerical simulation of suction side leading edge cavitation in a Francis turbine runner. A: International Symposium of Cavitation and Multiphase Flow. "The 3rd International Symposium of Cavitation and Multiphase FlowShanghai, China, April 19th-22nd, 2019 ISCM2019: accepted abstracts, full papers". Shanghai University Press, 2019, p. 1-8.