Now showing items 1-20 of 143

    • A generic lifetime estimation model for Francis turbines 

      Hvistendahl, Eivind (Master thesis, 2022)
      Ettersom mer intermitterende energikilder kobles til strømnettet må Francisturbiner i økende grad tilby balanseringstjenester. Dette fører til at turbinene periodisk opererer i suboptimale konfigurasjoner. Siden Francisturbiner ...
    • A new Design of a Francis Turbine in order to reduce Sediment Erosion 

      Meland, Hallvard (Master thesis, 2010)
      This Master Thesis is about the sand erosion challenges with the Francis turbines. The background for studying this subject is the fact that the sand erosion problem is a very negative factor for the development of new ...
    • A reference pelton turbine - design and efficiency measurements 

      Solemslie, Bjørn Winther; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2014)
      The Pelton turbine has been subject to a varying degree of research interest since the debut of the technology over a century ago. Despite its age there are gaps in the knowledge concerning the flow mechanisms effecting ...
    • Adaptively Learned Modeling for a Digital Twin of Hydropower Turbines with Application to a Pilot Testing System 

      Wang, Hong; Ou, Shiqi; Dahlhaug, Ole Gunnar; Storli, Pål-Tore Selbo; Skjelbred, Hans Ivar; Vilberg, Ingrid Kristine (Peer reviewed; Journal article, 2023)
      In the development of a digital twin (DT) for hydropower turbines, dynamic modeling of the system (e.g., penstock, turbine, speed control) is crucial, along with all the necessary data interface, virtualization, and dashboard ...
    • Aeroelastic analysis of an offshore wind turbine: Design and Fatigue Performance of Large Utility-Scale Wind Turbine Blades 

      Fossum, Peter Kalsaas (Master thesis, 2012)
      Aeroelastic design and fatigue analysis of large utility-scale wind turbine blades are performed. The applied fatigue model is based on established methods and is incorporated in an iterative numerical design tool for ...
    • Aeroelastic Instability and Flutter for a 10 MW Wind Turbine 

      Vatne, Sigrid Ringdalen (Master thesis, 2011)
      The goal of this thesis is to evaluate if flutter is a challenge to a 10 MW wind turbine. Flutter is an aeroelastic instability which occurs due to the interaction between the aerodynamic forces and the elasticity of the ...
    • An Experimental Investigation of the Hydroynamic Damping of Vibrating Hydrofoils 

      Bergan, Carl Werdelin; Tengs, Erik Os; Solemslie, Bjørn Winther; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2019)
      As Francis turbines are chasing a higher efficiency, while trying to accommodate a wider load region, turbine blade fatigue is becoming a more pronounced problem. Details of the Fluid-Structure Interaction (FSI) between ...
    • Application of hydro-abrasive erosion model from IEC 62364:2019 standard in Francis turbines 

      Acharya, Nirmal; Gautam, Saroj; Chitrakar, Sailesh; Trivedi, Chirag; Dahlhaug, Ole Gunnar (Peer reviewed; Journal article, 2022)
      Hydro-abrasive erosion in hydraulic turbines is critical and one of the prominent issue due to its association with maintenance costs and production losses in the hydropower plant. IEC 62364:2019* standard guide focuses ...
    • Blade passage modeling strategy for hydraulic turbine 

      Gong, Ruzhi; Trivedi, Chirag; Dahlhaug, Ole Gunnar; Nielsen, Torbjørn Kristian (Journal article; Peer reviewed, 2017)
      CFD has played a significant role to investigate the performance and improve the design of hydraulic turbines; however, the improvement of CFD method demands powerful computer resources including time, CPU, memory, and ...
    • Calibration and uncertainty analysis of pressure sensors used for dynamic measurements 

      Melaaen, Aase Sørum (Master thesis, 2017)
      Dynamic calibration of pressure sensors is challenging. Often, steady-state calibration is applied on pressure sensors used to measure dynamical measurements. Steady-state calibration does not represent the dynamic behavior ...
    • Calibration of strain gauges on a model runner blade combining numerical and experimental data 

      Kverno, Johannes Opedal; Iliev, Igor; Solemslie, Bjørn Winther; Dahlhaug, Ole Gunnar (Peer reviewed; Journal article, 2023)
      In this paper, we present the calibration setup, method, and results for a set of strain gauges installed on the trailing edge of the runner blades of a model Francis turbine. The calibration work is done as a step in the ...
    • CFD Analysis of a Pelton Turbine 

      Barstad, Lorentz Fjellanger (Master thesis, 2012)
      A Pelton design software is currently being developed at the Waterpower laboratory at NTNU. The motivation behind this software is to streamline the parametric design process for Pelton turbines. A numerical flow model is ...
    • CFD Analysis of Wave Induced Loads on Tidal Turbine Blades 

      Holst, Martin Aasved (Master thesis, 2012)
      Abstract— The object of this paper is to investigate the influence of wave-current interaction on a tidal turbine. An experiment at Norwegian Marine Technology Research Institute (MARINTEK) has been carried out, and a CFD ...
    • CFD-analyse av en høytrykks Francis turbin 

      Holo, Anders Linde (Master thesis, 2011)
      I denne masteroppgaven har det blitt gjennomført «fluid structure interaction» (FSI) simuleringer av modellturbinen fra Tokke, ved innløpsbetingelser som var rapportert å gjelde ved best driftspunkt. Simuleringsresultatene ...
    • CFD-analyse av løpehjul og sugerør i en Francis turbin 

      Breivik, Simen Røst (Master thesis, 2011)
      Denne masteroppgaven evaluerer svingningene is sugerørsstrømingen til en Francis turbinved dellast. Bakgrunnen for dette studiet er delvis på grunn av verdens økende energibehov. Med varierende energipriser og vannivåer i ...
    • Challenges with onboard strain measurements on a model Francis turbine runner 

      Kverno, Johannes Opedal; Vefring, Gaute Elde; Iliev, Igor; Solemslie, Bjørn Winther; Dahlhaug, Ole Gunnar (Peer reviewed; Journal article, 2023)
      As the world transitions towards more renewable energy sources, as a step to reduce the emissions of CO2, intermittent and non-dispatchable sources like solar and wind will take up a larger proportion of the energy production. ...
    • A comprehensive review of verification and validation techniques applied to hydraulic turbines 

      Trivedi, Chirag; Dahlhaug, Ole Gunnar (Peer reviewed; Journal article, 2019)
      The paper critically reviews the verification and validation (VV) techniques applied to investigate hydraulic turbines. Although there are well-established standards such as AIAA G-077-1998 and ERCOFTAC guide for turbulence ...
    • Constraints of Parametrically Defined Guide Vanes for a High-Head Francis Turbine 

      Stojkovski, Filip; Lazarevikj, Marija; Markov, Zoran; Iliev, Igor; Dahlhaug, Ole Gunnar (Peer reviewed; Journal article, 2021)
      This paper is focused on the guide vane cascade as one of the most crucial stationary sub-systems of the hydraulic turbine, which needs to provide efficient inflow hydraulic conditions to the runner. The guide vanes direct ...
    • Control system on a wind turbine 

      Varpe, Steffen Andreas (Master thesis, 2008)
      The aim for this project is to prepare a wind turbine controller and a wind turbine computer model suitable for controller development. The wind turbine is a Vestas V27, and the wind turbine drive train is modified by ...
    • Control System on a Wind Turbine: Evaluation of Control Strategies for a Wind Turbine with Hydraulic Drive Train by Means of Aeroelastic Analysis 

      Frøyd, Lars (Master thesis, 2009)
      The evolution of wind turbines are going towards floating offshore structures. To improve the stability of these turbines, the weight of the nacelle should be as low as possible. The company ChapDrive has developed a ...