Modelling of the Francis turbine runner in power stations. Part II: Stress analysis

Abstract

The second part of this paper presents results of stress analysis of the whole Francis turbine runner at Derbendikan power station by using the Finite Element Method (FEM). Computations were carried out with appropriate boundary and loading conditions for water pressure obtained from CFD analysis. The analysis focuses on stress distribution in the runner blades. It has been found that the maximum stresses due to the water pressure are located at the trailing edge of the runner blade towards the transition between the blade and the crown. This explains why this region has been identified as a critical area for fatigue crack initiation in the Francis turbine runner. © 2009 WIT Press.