Blar i NTNU Open på forfatter "Dahlhaug, Ole Gunnar"

Viser treff 61-80 av 153

    • Experimental Investigation of a High Head Model Francis Turbine During Steady-State Operation at Off-Design Conditions 

      Bergan, Carl Werdelin; Goyal, Rahul; Cervantes, Michel; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2016)
      Francis-99 is a set of workshops aiming to determine the state of the art of high head Francis turbine simulations (flow and structure) under steady and transient operating conditions as well as promote their development ...

    • Experimental investigation on a high head model Francis turbine during load rejection 

      Goyal, Rahul; Bergan, Carl Werdelin; Cervantes, Michel; Gandhi, B. K.; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2016)
      Francis-99 is a set of workshop aiming to determine the state of the art of high head model Francis turbine simulations (flow and structure) under steady and transient operating conditions as well as to promote their ...

    • Experimental methods and design of a Pelton bucket 

      Solemslie, Bjørn Winther (Doctoral thesis at NTNU;2016:01, Doctoral thesis, 2016)
      The Pelton turbine is a widely used technology for power generation first patented in 1880. Despite being a mature technology, there is still little published knowledge regarding the design method of Pelton turbines. ...

    • Experimental study of a Francis turbine under variable-speed and discharge conditions 

      Trivedi, Chirag; Agnalt, Einar; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2018)
      This work investigates the unsteady pressure fluctuations in a hydraulic turbine that are observed during steep ramping. Although hydraulic turbines are expected to operate seamlessly during steep ramping, the resulting ...

    • 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 ...

    • Fast Transition between Operational Modes of a reversible Pump-Turbine 

      Svarstad, Magni Fjørtoft (Doctoral theses at NTNU;2019:49, Doctoral thesis, 2019)
      The future demands of energy production to balance more intermittent energy sources creates two main technical challenges for the hydro power production. Increased off-design operation, including both operation outside ...

    • Flexible operation of Francis turbines 

      Kverno, Johannes Opedal (Doctoral theses at NTNU;2023:387, Doctoral thesis, 2023)
      With the planned cuts in emissions, more of the electric energy will have to come from renewable sources. Two of the largest potential sources are wind- and solar, which have the downside of also being intermittent and ...

    • 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 ...

    • Francis turbines for variable speed operation 

      Iliev, Igor (Doctoral theses at NTNU;2020:79, Doctoral thesis, 2020)
      Ascribing to the recent trends of market-driven electricity production and increased deployment of non-dispatchable renewables globally, several researchers have suggested the use of variable speed technology to improve ...

    • Frekvensresponsmålinger ved Svartisen Kraftverk 

      Høigaard, Morten (Master thesis, 2010)
      Mål Simulere Svartisen Kraftverk i LVTrans og sammenligne med frekvensresponsmålinger. Oppgaven skal bearbeides utifra følgende punkter: 1) Kandidaten skal sette seg in i teorien bak og metoder for frekvens respons målinger ...

    • FSI investigation of a hydrofoil 

      Heggebø, Karoline Eiane (Master thesis, 2017)
      Due to the changes in electricity production where intermittent energy sources like wind and solar power increase their ratio, a stabilizing energy source is required, which hydropower plants provides. The stabilization ...

    • FSI Simulation of a Guide Vane 

      Rasmussen, Bjørn Erik S (Master thesis, 2016)
      When fluid flows over an object, vortexes can develop, depending on the geometry of the object and conditions in the flow. Unwanted vortexes can be generated around both stay vanes and guide vanes in a hydropower plant, ...

    • FSI-analysis of a Francis turbine 

      Bergmann-Paulsen, Jonas (Master thesis, 2012)
      Sediment erosion in Francis turbines is a big problem in hydropower plants in and around the Himalayas. The sediment composition in the rivers contains high levels of the hard mineral quarts. When the sediments enter the ...

    • Funksjonstest av ventilasjonsvifte 

      Lien, Kjell Erik (Master thesis, 2010)
      Økt fokus på energibruk i bygninger gjør det interessant å sjekke virkningsgrad til vifter for ventilasjonsformål som mistenkes å være lav. 15 \% av energien i nye bygg går i dag til å drive ventilasjonsvifter. Slik designen ...

    • High flexibility in Francis turbine operation and design philosophy: A review 

      Kverno, Johannes Opedal; Iliev, Igor; Dahlhaug, Ole Gunnar (Peer reviewed; Journal article, 2022)
      This paper examines and discusses how various operation schemes and design philosophies can prolong the expected lifetime of a hydro turbine subjected to many start-stop cycles and high ramping rates. With the proliferation ...

    • How to avoid gas supersaturation in the river downstream a hydro power plant 

      Gütle, Vera Franziska (Master thesis, 2021)
      Abstract will be available on 2022-10-01

    • Hydraulic design of a Francis turbine that will be influenced by sediment erosion 

      Dahl, Gjert Aaberge (Master thesis, 2014)
      High amount of sediments in the Himalayas are at present a large problem for power companies in Nepal, preventing them of utilizing the large amount of hydro power available in the area. In the Jhimruk power plant the ...

    • Hydraulic Design of Francis Turbine Exposed to Sediment Erosion 

      Gjøsæter, Kristine (Master thesis, 2011)
      Sediment erosion is a large problem for turbines operated in sand laden water, especially in the Himalayas and the Andes Mountains, where the contents of hard minerals in the rivers are high. A program called RenewableNepal ...

    • Hydraulic design of Francis turbine exposed to sediment erosion 

      Gogstad, Peter Joachim (Master thesis, 2012)
      High concentrations of sediments is a serious problem for hydropower stations in the Himalayas and the Andes Mountains. For run-of-river power plants sediment causes heavy erosion even with settling basins. This leads to ...

    • 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 ...