An Approach to Evaluate the Lifetime of a High Head Francis Runner

International audience; Nowadays, the electricity market is changing rapidly and the requirements for hydropower plant operators vary between base load electricity production and ancillary services with a high share of transient operational points. The institute for Energy Systems and Thermodynamics, together with partners from the industry, initiated a research project to investigate the effects of these new operational modes on the components of a hydraulic machine. Especially the runner is of high importance due to the long service time and unfavorable flow phenomena when operated at off design points. A method to evaluate the lifetime of a high head Francis runner should be developed to investigate the existing runner and to serve later on a possible procedure for the design stage. Therefore, prototype measurements with applied strain gauges have been carried out for validation purposes of the developed method. Unsteady Numerical flow simulations using the open-source software OpenFOAM and static as well as dynamic Finite Element calculations with Code Aster are performed to investigate the lifetime of the observed Francis runner. The research project is still ongoing but first results regarding the procedure and the methods will be shown in this paper.