Do not be Afraid of Small High-Speed Francis Turbines

In the first quarter of the last century hydraulic power plants were equipped with high-speed Francis turbines even in the situation when a contemporary project manager would suggest Kaplan turbine. The reason is simple. Mr. Kaplan patented his turbine only in 1912 [1], https://en.wikipedia.org/wiki/Viktor_Kaplan . Those high-speed Francis turbines have just reached their lifetime. Mainly runners need repair. Our customers’ respond is that even renowned firms refuse to deliver runners with better parameters. Offer is to replace whole turbine with Kaplan or to make a copy of the existing runner. This paper presents experience and results of such a high-speed runner design. The runner substituted the one of Prokopa & sons from 1939 in powerhouse and mill at Křemže stream. Virtual prototyping technique has been used.