Blar i Institutt for energi og prosessteknikk på forfatter "Iliev, Igor"
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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 ... -
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. ... -
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 ... -
Design study of a reversible lobe pump-turbine for low-head seawater pumped hydro storage applications
Gans, Luiz Henrique Accorsi (Doctoral theses at NTNU;2024:116, Doctoral thesis, 2024) -
Design-Optimization of a Francis turbine draft tube
Herland, Ingelin (Master thesis, 2020)Denne masteroppgaven omhandler optimalisering av sugerøret til en Francisturbin som opererer på variabelt turtall. Forbedrede design er diskutert relativt et referansedesign, i form av økt trykkgjenvinning gjennom sugerøret ... -
An experimental and numerical study of a three-lobe pump for pumped hydro storage applications
Gans, Luiz H.A.; Trivedi, Chirag; Iliev, Igor; Storli, Pål-Tore Selbo (Peer reviewed; Journal article, 2023)Pumped hydro storage (PHS) plays an important role as a matured technology that accounts for the vast majority of global energy storage capacity, and its expansion is therefore desirable. The expansion of PHS in mid- and ... -
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 ... -
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 ... -
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 ... -
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 ... -
Numerical study of a Francis turbine over wide operating range: Some practical aspects of verification
Trivedi, Chirag; Iliev, Igor; Dahlhaug, Ole Gunnar (Peer reviewed; Journal article, 2020)Hydropower plays an essential role in maintaining energy flexibility. Modern designs focus on sustainability and robustness using different numerical tools. Automatic optimization of the turbines is widely used, including ... -
On the Rotor Stator Interaction Effects of Low Specific Speed Francis Turbines
Agnalt, Einar; Iliev, Igor; Solemslie, Bjørn Winther; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2019)The rotor stator interaction in a low specific speed Francis model turbine and a pump-turbine is analyzed utilizing pressure sensors in the vaneless space and in the guide vane cascade. The measurements are analyzed relative ... -
Optimization of Francis Turbines for Variable Speed Operation Using Surrogate Modeling Approach
Iliev, Igor; Tengs, Erik Os; Trivedi, Chirag; Dahlhaug, Ole Gunnar (Peer reviewed; Journal article, 2020)Previous studies suggested variable speed operation (VSO) of Francis turbines as a measure to improve the efficiency at off-design operating conditions. This is, however, strongly dependent on the hydraulic design and, for ... -
Parameter based tool for Francis turbine guide vanes design using coupled MATLAB-ANSYS approach
Lazarevikj, Marija; Stojkovski, Filip; Markov, Zoran; Iliev, Igor; Dahlhaug, Ole Gunnar (Peer reviewed; Journal article, 2022)The complex geometry of Francis turbine components can be defined parametrically so that automatic optimization techniques based on parametrization can be used. This is convenient for a hydraulic redesign of individual ... -
Pressure Pulsation and Stresses in a Francis Turbine Operating at Variable Speed
Sannes, Daniel Braathen (Master thesis, 2018)The introduction of new intermittent energy sources on the electrical grid increases the need of regulated power to ensure stability of grid frequency. Hydropower has the unique possibility to deliver both stability and ... -
Sediment erosion in the labyrinths of Francis turbine: A numerical study
Gautam, Saroj; Acharya, Nirmal; Chitrakar, Sailesh; Neopane, Hari Prasad; Iliev, Igor; Dahlhaug, Ole Gunnar (Peer reviewed; Journal article, 2022)Development of new hydropower projects in Himalayan regions aims for the efficient performance of the turbine with lesser operation and maintenance cost. Over the past two decades, significant efforts have been made to ... -
Simplified hydrodynamic analysis on the general shape of the hill charts of Francis turbines using shroud-streamline modeling
Iliev, Igor; Trivedi, Chirag; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2018)The paper presents a simplified one-dimensional calculation of the efficiency hill-chart for Francis turbines, based on the velocity triangles at the inlet and outlet of the runner's blade. Calculation is done for one ... -
Test of a Francis turbine with new guide vanes
West, Halvor Hølmkjær (Master thesis, 2022)Verden har gjennom Parisavtalen i 2015 og senere den oppdaterte Glasgowavtalen i 2021 blitt enig om å fase ut kullkraft. I tillegg til et større forbruk med store variasjoner, er det et behov for å bygge ut fornybare ... -
Test of a Francis turbine with variable speed operation
Langleite, Gro Mari Kjellstadli (Master thesis, 2020)I disse dager med utfordringer knyttet til frekvens responsen på nettet, kan Francis turbiner ha mulighet til å tilføre mer intermitterende energi på nettet. Dessverre kan løpehjulet oppleve utmatning eller sprekke grunnet ... -
Variable-speed operation and pressure pulsations in a Francis turbine and a pump-turbine
Iliev, Igor; Trivedi, Chirag; Agnalt, Einar; Dahlhaug, Ole Gunnar (Journal article; Peer reviewed, 2019)The paper presents result from model measurements of the efficiency and pressure pulsation intensities for two low-specific-speed hydraulic turbines operated at variable speed, namely, one splitter-bladed Francis turbine ...