Blar i USN Open Archive på forfatter "Vågsæther, Knut"

Viser treff 21-40 av 44

    • Minimum ignition energy of hydrogen and hydrogen-carrying fuels 

      Jakar, Sarthak (Master thesis, 2022)
      Hydrogen is touted to be the fuel of the future leading to low carbon emissions globally. But as this fuel is being popularized all over the world for all the industry sectors, very little is known about the combustion ...

    • Modeling an image analysis of FAE 

      Vågsæther, Knut; Christensen, Svein Olav; Bjerketvedt, Dag (Conference lecture, 2008-09)

    • Modeling and simulation of hydrogen flow in a maritime fuel cell system 

      Valand, Stian (Master thesis, 2022)
      The climate change challenge is one of today's greatest challenges, and the need to reduce emissions is more significant than ever. Hydrogen can be a potential zero-carbon fuel, and together with a maritime fuel cell system, ...

    • Modeling of evaporation of hydrogen during accidental releases 

      Afzali, Mojtaba (Master thesis, 2021)
      Hopefully, in the near future, liquid hydrogen will be commonly utilized as energy. The cleanest fuel that the primary limit of producing and using it, is safety issues. High possibility safety issues are generated by large ...

    • Modelling of fast fueling of pressurized hydrogen tanks for maritime applications 

      Kesana, Netaji Ravikiran; Welahettige, Prasanna; Hansen, Per Morten; Ulleberg, Øystein; Vågsæther, Knut (Journal article; Peer reviewed, 2023)
      This paper studies fast fueling of gaseous hydrogen into large hydrogen (H2) tanks suitable for maritime applications. Three modeling methods have been developed and evaluated: (1) Two-dimensional computational fluid dynamic ...

    • Modelling of gas explosions 

      Vågsæther, Knut (Doctoral theses at NTNU;2010:221, Doctoral thesis; Peer reviewed, 2010-12-03)
      The content of this thesis is a study of gas explosions in complex geometries and presentation and validation of a method for simulating flame acceleration and deflagration to detonation transition. The thesis includes a ...

    • Numerical study of premixed gas explosion in a 1-m channel partly filled with 18650 cell-like cylinders with experiments 

      Henriksen, Mathias; Vågsæther, Knut; Lundberg, Joachim; Forseth, Sissel; Bjerketvedt, Dag (Peer reviewed; Journal article, 2022)
      Abused and defective Li-ion cells can cause a catastrophic failure of a Li-ion battery (LIB), leading to severe fires and explosions. In recent years, several numerical and experimental studies have been conducted on the ...

    • One-dimensional model of turbulent flow of non-Newtonian drilling mud in non-prismatic channels 

      Welahettige, Prasanna Kumara Welahetti; Lundberg, Joachim; Bjerketvedt, Dag; Lie, Bernt; Vågsæther, Knut (Peer reviewed; Journal article, 2019)
      One-dimensional model of non-Newtonian turbulent flow in a non-prismatic channel is challenging due to the difficulty of accurately accounting for flow properties in the 1-D model. In this study, we model the 1-D Saint–Venant ...

    • Pressure wave propagation in Managed Pressure Drilling- model comparison with real life data 

      Berg, Christian; Stakvik, Jon Åge; Lie, Bernt; Vågsæther, Knut; Kaasa, Glenn-Ole (Peer reviewed; Journal article, 2019)
      Drilling for oil and gas is a complex process, involving pumping of fluid through kilometers of pipes. Even though the drilling fluid has a high speed of sound (˜1000 m/s), the large lengths involved make pressure wave ...

    • Proceedings of the Tenth International Seminar on Fire and Explosion Hazards, 22-27 May 2022, Oslo, Norway 

      Vågsæther, Knut; Lach, Agnieszka; Bradley, Derek; Lundberg, Joachim (Conference object; Peer reviewed, 2022)
      The Tenth International Seminar on Fire and Explosion Hazards (ISFEH10) organized in Oslo, Norway from 22 to 27 May 2022, is a place to share research on the physical effects of hazards, prediction methods for consequences, ...

    • A Real-Time Flow-Measuring Algorithm for Open Venturi Channel Non-Newtonian Flow 

      Welahettige, Prasanna Kumara Welahetti; Lie, Bernt; Vågsæther, Knut (Peer reviewed; Journal article, 2019)
      A real-time flow measuring algorithm is developed for the open Venturi channel non-Newtonian flow measurement. Using a single level sensor reading at downstream of the open Venturi channel, a drilling-well return flow rate ...

    • Release of liquid CO2 from the bottom of a duct 

      Mohammed Ibrahim, Osama Kabbashi; Gaathaug, Andre Vagner; Hansen, Per Morten; Bjerketvedt, Dag; Vågsæther, Knut (Peer reviewed; Journal article, 2023)
      This paper presents experimental results of the rapid phase transition of liquid CO2 released from the bottom of a small rectangular duct (BR). The aim is to consider the factors influencing the phase transitions and the ...

    • Riemann solver for combustion waves 

      Vågsæther, Knut (Professional article, 2011-05-03)

    • Safety review and risk study for hydrogen storage 

      Vindenes, Cathrine (Master thesis, 2022)
      The energy sector is rapidly adjusting towards the green change by cutting emissions and using more renewable energy sources. The interest in hydrogen economy has increased in the last decade due to environmental concerns ...

    • Simulation of burning velocities in gases vented from thermal run-a-way lithium ion batteries 

      Johnsplass, Jonathan; Henriksen, Mathias; Vågsæther, Knut; Lundberg, Joachim; Bjerketvedt, Dag (Journal article; Peer reviewed, 2017)
      This paper describes the results from simulations of laminar burning velocities in the premixed air and flammable gases vented from abused Li-ion batteries. The released mixture from such batteries contain mixtures of ...

    • Simulation of FA and DDT in a channel with repeated obstacles with an under-resolved mesh 

      Vågsæther, Knut; Bjerketvedt, Dag (Conference object; Peer reviewed, 2009)

    • Simulation of flame acceleration and DDT in H-2-air mixture with a flux limiter centered method 

      Vågsæther, Knut; Knudsen, Vegeir; Bjerketvedt, Dag (Journal article; Peer reviewed, 2007)
      Flame acceleration and deflagration to detonation transition (DDT) is simulated with a numerical code based on a flux limiter centered method for hyperbolic differential equations. The energy source term is calculated by ...

    • Simulation of flame acceleration in an obstructed tube with LES 

      Vågsæther, Knut; Bjerketvedt, Dag (Conference object; Peer reviewed, 2007)

    • Simulation of hydrogen tank refueling 

      Salcido Sanchez, Jose Luis (Master thesis, 2021)
      Several simulations of hydrogen filling process for a type IV tank were completed using openFOAM Computational Fluid Dynamics (CFD) open-source code. CFD codes have been proven to be a useful method for estimating temperature ...

    • Simulation of Hydrogen Tank Refuelling 

      Mojarrad, Masih (Master thesis, 2020)
      As an alternative to fossil fuels and as a sustainable energy carrier, there are considerable interestsin investigating hydrogen. Hence, it seems significant to evaluate the behavior of hydrogen in refueling or storing. ...