Browsing NTNU Open by Author "Trivedi, Chirag"
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A review on fluid structure interaction in hydraulic turbines: A focus on hydrodynamic damping
Trivedi, Chirag (Journal article; Peer reviewed, 2017)Hydraulic turbines include stationary and rotating components. The interaction of the components, mainly between the runner blades and distributor vanes, is critical when the frequency of the rotor-stator interaction (RSI) ... -
An Analytical quasi 2D steady-state Francis turbine model using first principles
Storli, Pål-Tore Selbo; Trivedi, Chirag (Journal article; Peer reviewed, 2022) -
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 ... -
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 ... -
Design of a Turbine That Utilizes the Energy in Spill Water of Large Ships
Meek, Christoffer (Master thesis, 2018)In this master thesis, a Straflo turbine prototype used for energy recovering in large ships was tested, evaluated, and redesigned. The main goals were first to evaluate the performance of the prototype based on efficiency ... -
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) -
Erosion in Francis turbines due to geometrical positioning of runner and guide vanes
Acharya, Nirmal (Doctoral theses at NTNU;2022:301, Doctoral thesis, 2022)Hydro-abrasive erosion in turbine components is one of the prominent operational challenges for hydropower plants located across basins of regions such as Himalayas in Asia, the Andes in South America, and Pacific coast. ... -
Experimental and Numerical Studies of a High-Head Francis Turbine: A Review of the Francis-99 Test Case
Trivedi, Chirag; Cervantes, Michel; Dahlhaug, Ole Gunnar (Peer reviewed; Journal article, 2016)Hydraulic turbines are widely used to meet real-time electricity demands. Computational fluid dynamic (CFD) techniques have played an important role in the design and development of such turbines. The simulation of a ... -
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 ... -
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 ... -
Fluid structure interaction in circular blade cascade
Jeyakaran, Roshan (Master thesis, 2022)Når væske strømmer over en struktur, kan det utvikles uønskede virvler. I vannkraftindustrien er dette et stort problem som kan genereres i ledeskovler, der virvler går på tvers inn i løperen og forårsaker vibrasjoner. ... -
Fluid-structure interactions in Francis turbines: A perspective review
Trivedi, Chirag; Cervantes, Michel (Journal article; Peer reviewed, 2017)Competitive electricity prices and reduced profit margins have forced hydraulic turbines to operate under critical conditions. The demand for extended operating ranges and the high efficiency of the turbine runners have ... -
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 ... -
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 validation of a Francis turbine at runaway operating conditions
Trivedi, Chirag; Cervantes, Michel; Gandhi, BK (Journal article; Peer reviewed, 2016)Hydraulic turbines exhibit total load rejection during operation because of high fluctuations in the grid parameters. The generator reaches no-load instantly. Consequently, the turbine runner accelerates to high speed, ... -
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 a Francis turbine during start-stop
Eitzen, Fabian Camillo (Master thesis, 2022)En numerisk studie av en Francis-turbin under off-design drift har blitt utført for å undersøke bladbelastningen forårsaket av turbulensfenomener nært grensesnitt og trykkpulseringer. Målet med arbeidet var å identifisere ... -
Investigation of air driven ejector for ballast pump
Olsvold, Vegard Vetvik (Master thesis, 2022)Ballastpumper spiller en viktig rolle for å opprettholde stabiliteten til skip ved å pumpe sjøvann inn eller ut av ballastvannstankene under lasting, lossing og trim av fartøyet. Under pumpedrift må impellerene være nedsenket ... -
Investigation of corner vortex in radial cascade and interaction with the trailing edge vortex
Kamalaraja, Arunn (Master thesis, 2021)Virvelavløsning fra objekter er et strømningsfenomen som kan finnes blant industrielle applikasjoner. Strømningsfenomenet avløser virvler som fører til vibrasjon. Denne vibrasjonen kan forsterkes, dersom virvelavløsningsfrekvensen ...