The Francis turbine is the most common type of water turbine used in Norwegian hydropower plants, and has been for many years. About half of the world’s Francis turbines are found in Norwegian plants. But for the past few years, more and more of these turbines have been breaking.
The problem has been particularly pronounced in high-pressure turbines, which run at waterfall heights of 200-300 metres. Professor Ole Gunnar Dahlhaug of the Department of Energy and Process Engineering at the Norwegian University of Science and Technology think to know what’s causing the problem, but they aren’t able to make the calculations that would enable to better understand it. The problem has to do with resonance, and an interaction between pressure from the water and the steel in the turbine blades. To solve this problem, researchers, power companies and turbine manufacturers have all come together to collaborate. Competing businesses are sharing and comparing data in several different research projects, all working towards the same goal.