Browsing NTNU Open by Author "Dahlhaug, Ole Gunnar"
Now showing items 81-100 of 153
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Hydropower Providing Flexibility for a Renewable Energy System: Three European Energy Scenarios
Siemonsmeier, Marius; Baumanns, Philipp; van Bracht, Niklas; Schönefeld, Maik; Schönbauer, Andrea; Moser, Albert; Dahlhaug, Ole Gunnar; Heidenreich, Sara (Research report, 2018) -
Hydropower Providing Flexibility for a Renewable Energy System: Three European Energy Scenarios
Siemonsmeier, Marius; Baumanns, Philipp; van Bracht, Niklas; Schönefeld, Maik; Schönbauer, Andrea; Moser, Albert; Dahlhaug, Ole Gunnar; Heidenreich, Sara (Report, 2018)The Horizon 2020 Project ‘Increasing the value of Hydropower through increased Flexibility (HydroFlex)’ aims towards scientific and technological breakthroughs to enable hydropower to operate with very high flexibility in ... -
Impact from flexible operations on High Head Francis turbines
Skorpen, Andreas Nilssen (Master thesis, 2018)Today the European energy grid contains more renewable energy sources than ever before, yet there is little to no research on how the increased amount affects the cost structure of the remaining energy sources of the grid. ... -
Interaction between trailing edge wake and vortex rings in a Francis turbine at runaway condition: Compressible large eddy simulation
Trivedi, Chirag; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2018)The present study aims to investigate the unsteady flow phenomenon that produces high energy stochastic fluctuations in a highly skewed blade cascade. A complex structure such as a turbine is operated at runaway speed, ... -
Investigation and implementation of turbulent wind in a specialized software tool for offshore wind turbines
Pedersen, Hans Børge (Master thesis, 2014)This thesis presents the theoretical models and standards behind the generation of turbu-lence in aeroelastic software. The required knowledge behind offshore wind have beeninvestigated and the necessary changes from onshore ... -
Investigation of a Francis turbine during speed variation: Inception of cavitation
Trivedi, Chirag; Iliev, Igor; Dahlhaug, Ole Gunnar; Zoran, Markov; Engstrom, Fredrik; Lysaker, Henning (Peer reviewed; Journal article, 2020)Variable-speed operation of a hydro turbine is considered as an alternative option to meet fluctuating energy demand as it allows high-ramping rate. Cavitation can be a limiting factor to utilize the variable-speed technology ... -
Investigation of sediment erosion phenomenon for different blade angle distribution in Francis runner
Acharya, Nirmal; Trivedi, Chirag; Gautam, Saroj; Dahlhaug, Ole Gunnar (Peer reviewed; Journal article, 2021)Wear and tear of hydraulic turbine due to sediment erosion is one of the major problems in hydropower plants located in the Himalayan and Andes regions. High sediment concentration in water of such areas wears down the ... -
Investigation of suction capability of a centrifugal pump impeller
Fosse, Rita Ones (Master thesis, 2021)Sentrifugalpumper er en turbomaskin, hvor løpehjulet øker trykket i væsken. Den første kjente prototypen for en sentrifugalpumpe eksisterte allerede på 1400-tallet. Det har vært en konstant utvikling fra den første kjente ... -
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 the Unsteady Pressure Pulsations in the Prototype Francis Turbines -Part 1: Steady State Operating Conditions
Trivedi, Chirag; Gogstad, Peter Joachim; Dahlhaug, Ole Gunnar (Journal article, 2018)Hydropower is one of the most reliable renewable sources of electricity generation. With high efficiency and good regulating capacity, hydropower has the ability to meet rapid changes in power demand. Large investments in ... -
Investigation of the unsteady pressure pulsations in the prototype Francis turbines during load variation and startup
Trivedi, Chirag; Gogstad, Peter Joachim; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2017)This work investigates the unsteady pressure fluctuations in two prototype Francis turbines during load variation and start-up. Although hydraulic turbines are expected to experience such events over their lifetime, the ... -
Investigations of unsteady pressure loading in a Francis turbine during variable-speed operation
Trivedi, Chirag; Agnalt, Einar; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2017)Current study was aimed to investigate the unsteady pressure loading in a model Francis turbine under variable-speed configurations. Focus was to investigate the time-dependent characteristic frequencies and the pressure ... -
ldentifisering av sprekker i Francis turbiner
Dahlhaug, Ole Gunnar; Støren, Gine Kirkebøen (HydroCen brief;Nr. 22, Report, 2021) -
Leakage Vortex Progression through a Guide Vane’s Clearance Gap and the Resulting Pressure Fluctuation in a Francis Turbine
Acharya, Nirmal; Gautam, Saroj; Chitrakar, Sailesh; Trivedi, Chirag; Dahlhaug, Ole Gunnar (Peer reviewed; Journal article, 2021)A clearance gap (CG) between guide vanes (GVs) and facing plates exists at both ends of a Francis turbine and allows the opening angle to be adjusted for varying operating conditions. Leakage flow is induced through this ... -
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 ... -
Modal testing of the Francis-99 runner
Solemslie, Bjørn Winther; Dahlhaug, Ole Gunnar; Sigurdsson, Bjarki; Tengs, Erik Os (Peer reviewed; Journal article, 2021)The Francis-99 low specific speed Francis runner has undergone much study in the years since it was first made available to the public. The High Head Francis(HiFrancis) project, hosted by the Waterpower Laboratory at NTNU, ... -
Modelltester av Peltonturbiner ved Vannkraftlaboratoriet
Trefall, Stine (Master thesis, 2011)Ved design av nye turbiner kan modelltester gjennomføres for å kartlegge driftsområde og ytelse. Informasjon fra testene kan benyttes til å avdekke eventuelle feil og estimere levetid. Modelltester kan videre benyttes til ... -
Multi Stage Turbine for wave energy plant
Mong, Nina (Master thesis, 2007)A wave energy plant based on the patended Seawave Slot-Cone Generator (SSG) is under development by the Norwegian company WAVEenergy AS. The concept is based on the principle that the incoming waves will run uphill on a ... -
Numerical and experimental investigation of erosive wear in Francis runner blade optimized for sediment laden hydropower projects in Nepal
Gautam, Saroj; Acharya, Nirmal; Lama, Ram; Chitrakar, Sailesh; Neopane, Hari Prasad; Zhu, Baoshan; Dahlhaug, Ole Gunnar (Peer reviewed; Journal article, 2022)The design of the Francis turbine aims to maximize its performance in terms of efficiency. This design approach has overlooked effects on the turbine due to sediment erosion for power plants operating under high sediment ... -
Numerical and experimental investigation of the unsteady flow field over a simplified hydrofoil plate
Pislevikj, Jasmina (Master thesis, 2017)In this thesis, the behavior of a simplified hydrofoil in an unsteady water flow field is tested. Due to frequent load variations in high head Francis turbines, the runner vanes happen to break. Rotor stator interaction ...