• Damping Measurements on a Multi-Blade Cascade with Multiple Degrees of Freedom: A Francis-99 Test Case 

      Bergan, Carl Werdelin; Tengs, Erik Os; Solemslie, Bjørn Winther; Østby, Petter Thorvald Krogh; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2019)
      Due to thinner blades and higher demands for flexibility, the high-head Francis runners designed today face considerable challenges that severely affect the runners' expected lifetime. For many high-head Francis runners, ...
    • Experimental Study of a Low-Specific Speed Francis Model Runner during Resonance 

      Agnalt, Einar; Østby, Petter Thorvald Krogh; Solemslie, Bjørn Winther; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2018)
      An analysis of the pressure in a runner channel of a low-specific speed Francis model runner during resonance is presented, which includes experiments and the development of a pressure model to estimate both the convective ...
    • Fatigue loads in a Francis turbine runner 

      Lødemel, Eirik (Master thesis, 2019)
      Utvidelsen av fornybare energikilder i det europeiske energimarkedet fører til en økende etterspørsel etter regulerbare energikilder som kan stabilisere nettfrekvensen. Vannkraft kan fungere som en regulerbar energikilde, ...
    • Fatigue loads in a Francis turbine runner 

      Lødemel, Eirik (Master thesis, 2019)
      Utvidelsen av fornybare energikilder i det europeiske energimarkedet fører til en økende etterspørsel etter regulerbare energikilder som kan stabilisere nettfrekvensen. Vannkraft kan fungere som en regulerbar energikilde, ...
    • Fluid structure interaction of Francis-99 turbine and experimental validation 

      Østby, Petter Thorvald Krogh; Agnalt, Einar; Haugen, Bjørn; Billdal, Jan Tore; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2019)
      The ability to predict a francis runners dynamic response to the exciting forces is paramount to avoid unwanted disintegration of the turbines components. In this article, each of the principal factors contributing to the ...
    • Hydrodynamic Damping of a Fluttering Hydrofoil in High-speed Flows 

      Bergan, Carl Werdelin; Solemslie, Bjørn Winther; Østby, Petter Thorvald Haug; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2018)
      A hydrofoil resembling a high head Francis runner blade was submerged in a rectangular channel and attached to the walls in a fixed-beam configuration. The hydrofoil was excited by piezoelectric Macrofiber composite actuators ...