Blar i NTNU Open på forfatter "Nielsen, Torbjørn Kristian"

Viser treff 21-40 av 76

    • Effektregulering av vannkraftverk med Peltonturbiner 

      Riise, Tarjei Lid (Master thesis, 2016)
      Denne masteroppgaven er en fortsettelse av prosjektoppgaven "Dynamisk dimensjonering av vannkraftverk". Evanger kraftverk skal rehabiliteres. Kraftverket er driftet av BKK og er Norges 10. største. Ønsket er nå å oppnå mer ...

    • Eksperimentell oppgave relatert til Gibson-metoden 

      Østgård, Idun Schjerven (Master thesis, 2008)
      Det er kjent at Gibsons metode gir store avvik ved lave gjennomsnittshastigheter og korte avstander mellom måletverrsnittene, noe som gjør metoden lite egnet i mange kraftverk. Våren 2008 ble det etablert en testrigg i ...

    • Evaluering av modulert kavitasjon i vannkraftturbiner 

      Kolsaker, Kristin Tessem (Master thesis, 2013)
      Det har lenge vært ønskelig å bygge en kavitasjonsrigg ved Vannkraftlaben for å forske på modulert kavitasjon på vingeprofiler. Formålet med oppgaven er å prosjektere en slik rigg, samt beskrive nødvendig instrumentering ...

    • Fast transition from pump to turbine mode of operation 

      Svarstad, Magni Fjørtoft; Nielsen, Torbjørn Kristian (Journal article; Peer reviewed, 2018)
      The reversible pump turbine (RPT) is a suitable machine to control fluctuations in the energy market. The usage of RPTs for this purpose will increase the number of operational mode changes of the machine. In order to ...

    • Flow and efficiency measurements by use of clamp-on ultrasonic equipment 

      Dhital, Tilak Chand (Master thesis, 2019)
      Hydrauliske virkningsgradsmålinger er nødvendig for å få informasjon om ytelsen til hydrauliske maskiner i vannkraftverk. Virkningsgradsmålinger utføres vanligvis før og etter rehabilitering av vannkraftverk. Det er ofte ...

    • Flow conditions in spiral casing and the influence of various bend geometries 

      Augustson, Tage Morken (Master thesis, 2013)
      Both previous experiments and CFD simulations show that bends have a significant influence on the downstream flow field, especially by causing so-called ?skewed velocity profiles?. Based on the simulations carried out in ...

    • Flow in Pelton turbines 

      Furnes, Kjartan (Master thesis, 2013)
      The flow in Pelton turbines is subsonic, turbulent, multiphase (water, air, and water vapor from cavitation), has high speeds, sharp gradients, free surface and dynamic boundary conditions. A static grid is unsuitable for ...

    • Hydraulic scale modelling and thermodynamics of mass oscillations in closed surge tanks 

      Vereide, Kaspar; Lia, Leif; Nielsen, Torbjørn Kristian (Journal article; Peer reviewed, 2015)
      The design and results from a hydraulic scale model of mass oscillations in a hydropower plant with a closed surge tank constructed as an underground rock cavern are presented. The results from the model test of an existing ...

    • Hydraulics and Thermodynamics of Closed Surge Tanks for Hydropower Plants 

      Vereide, Kaspar Vatland (Doctoral thesis at NTNU;2016:20, Doctoral thesis, 2016)
      This work has studied the hydraulic and thermodynamics of closed surge tanks for hydropower plants. Surge tanks are applied in hydropower plants to control and reduce the acceleration forces of the water during change of ...

    • Hydropower 

      Cavazzini, Giovanna; Storli, Pål-Tore Selbo; Nielsen, Torbjørn Kristian (Chapter, 2021)
      Hydropower has a very long tradition in many countries and was first used to provide working power for grinding corn, sawing timber and other previously manual tasks. The development of the modern turbine took a big step ...

    • Hysteresis characteristic in the hump region of a pump-turbine model 

      Li, Deyou; Wang, Hongjie; Chen, Jinxia; Nielsen, Torbjørn Kristian; Qin, Daqing; Wei, Xianzhu (Peer reviewed; Journal article, 2016)
      The hump feature is one of the major instabilities in pump-turbines. When pump-turbines operate in the hump region, strong noise and serious fluctuations can be observed, which are harmful to their safe and stable operation ...

    • Improvement of response time and cutting capability of Blow Out Preventer (BOP) 

      Østby, Petter (Master thesis, 2008)
      There is a general demand in the market for BlowOut Preventers (BOP), which are capable of cutting tougher materials and cutting them faster than what is available today. This will give better safety and a more efficient ...

    • Improvement of response time and cutting capability of Blow Out Preventer (BOP) 

      Ostby, Petter (Master thesis, 2008)
      There is a general demand in the market for BlowOut Preventers (BOP), which are capable of cutting tougher materials and cutting them faster than what is available today. This will give better safety and a more efficient ...

    • Improvements of a Kaplan type small turbine: Forbedre og vidreutvikle en Kaplan småturbin 

      Fjærvold, Lars (Master thesis, 2012)
      The goal with this master thesis was to establish Hill diagrams and improve a Kaplan turbine intended for use in Afghanistan. The turbine efficiency has been tested in setting 1 and 2. Turbine efficiency in setting 3 and ...

    • Increasing power output from Francis turbines: Effektøkning i vannkraftverk med Francis turbiner 

      Brunes, Bente Taraldsten (Master thesis, 2009)
      The main objective in this thesis was to investigate a potential increase of power output from the existing turbines at Ruacana Hydropower Station. This was restricted to only consider a runner replacement, and only technical ...

    • Investigation of the Flow through the Runner of a Cross-Flow Turbine 

      Walseth, Eve Cathrin (Master thesis, 2009)
      The cross-flow turbine is unique due to the generation of power during two stages. The water flows through the rectangular cross-section nozzle and enters the runner, where the first stage power is generated. The water ...

    • Investigation of unsteady flow in the vaneless gap between impeller and diffusor. 

      Strømme, Hans Kristian (Master thesis, 2016)
      I denne oppgaven er det undersøkt hvorvidt vibrasjoner i en vertikalsentrifugalpumpe stammer fra sekundærstrømninger i gapet mellom impellerog diffusor. En model av dette gapet ble laget ut fra arbeidstegninger overpumpen ...

    • LDV Measurements in Centrifugal Pump Diffuser 

      Bjørgen, Karl Oskar Pires (Master thesis, 2015)
      This thesis describes experimental research on the flow inside a vaned diffuser of a centrifugal pump. The measurements were conducted inside one of the ten curved diffuser channels on the single-stage centrifugal pump ...

    • Måling av pumpevirkningsgrad ved hjelp av termodynamisk metode 

      Ljones, Gudrun (Master thesis, 2009)
      Målet med denne oppgaven er å måle pumpevirkningsgrad ved hjelp av termodynamisk metode. Termodynamisk metode måler strømningstapene over en hydraulisk strømningsmaskin. For strømningsmaskiner med løftehøyde over 100 m ...

    • Measurements and simulations of turbines on common grid 

      Nielsen, Torbjørn Kristian; Storli, Pål-Tore Selbo (Journal article; Peer reviewed, 2014)
      Speed droop control is of basic importance for the primary governing in the Nordic grid. The speed droop control. a mandatory and build-in regulatory loop on all larger units. is automatically changing the produced power ...