Blar i USN Open Archive på forfatter "Vågsæther, Knut"
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A case study of fire and explosion risk at hydrogen facilities, an ignition probability study
Meland, Signe Natten (Master thesis, 2024)Hydrogen is an essential energy carrier, making it very important for the global energy decarbonization process. Because of limited knowledge of ignition mechanisms, its elevated ignition risk compared to other gases present ... -
A solution method for one-dimensional shallow water equations using flux limiter centered scheme for open Venturi channels
Welahettige, Prasanna Kumara Welahetti; Vågsæther, Knut; Lie, Bernt (Journal article; Peer reviewed, 2018)The one-dimensional shallow water equations were modified for a Venturi contraction and expansion in a rectangular open channel to achieve more accurate results than with the conventional one-dimensional shallow water ... -
An experimental investigation of rapid boiling of CO2
Tøsse, Sindre; Vågsæther, Knut; Bjerketvedt, Dag (Journal article; Peer reviewed, 2014-09-27)Storage of pressurized liquified gases is a growing safety concern in many industries. Knowledge of the thermodynamics and kinetics involved in the rapid depressurization and evaporation of such substances is key to the ... -
An experimental study of temperatures in cloud from release of flashing liquid CO2 in 3m long channel.
Adhikari, Amrit; Gaathaug, André Vagner; Bjerketvedt, Dag; Vågsæther, Knut (Journal article; Peer reviewed, 2014)Flashing of the liquid CO2 is an accidental hazards that may occurs in many industrial sector such as, process industries, carbon capture and storage projects, crude oil extraction process etc. Sometimes the accidental ... -
Boiling liquid expanding vapour explosion in CO2 small scale experiments
Bjerketvedt, Dag; Egeberg, Kjersti; Ke, Wei; Gaathaug, André Vagner; Vågsæther, Knut; Nilsen, Sandra Hennie (Journal article; Peer reviewed, 2011-04)Carbon capture and storage systems require handling large volumes of high pressure CO2. Having thorough knowledge of the related hazards is essential, as is knowing how to prevent, detect, control and mitigate accidents. ... -
CFD Simulation of Solidification of non-Newtonian Fluid Flowing in a Complex Geometry Pipeline in Turbulent Flow Regime
Vesjolaja, Ludmila; Bujalski, Jakub M; Vågsæther, Knut (Journal article; Peer reviewed, 2018)In this CFD (Computational Fluid Dynamics) study, the turbulent flow of a non-Newtonian fluid through an industrial scale transportation pipeline is modelled in Ansys Fluent®, with a focus on the fluid solidification due ... -
CFD-Simulations of inhomogeneous H2-air explosions
Aghaabbasi, Omid (Master thesis, 2021)Since demands for energy resources increase globally in recent years due to growth of application consumption, finding alternative resources for traditional fossil fuels raises. These current fuels are diminishing continuously ... -
Comparison of OpenFoam and ANSYS Fluent. Compitational Fluid Dynamic Simulation of Gas-Gas Single Phase Mixing with and without Static Mixer
Welahettige, Prasanna Kumara Welahetti; Vågsæther, Knut (Chapter; Peer reviewed, 2016)Gas-gas single phase mixing were numerically evaluated with static mixer and without static mixer using OpenFoam and ANSYS Fluent codes. The main goal was the gas-gas mixing simulation comparison between ANSYS Fluent and ... -
Computational fluid dynamics study of flow depth in an open Venturi channel for Newtonian fluid
Welahettige, Prasanna Kumara Welahetti; Lie, Bernt; Vågsæther, Knut (Journal article; Peer reviewed, 2017)Open Venturi channel flow measurement could be a cheap method to be used in drill bit pressure control. The main objective of this study is to identify the factors related with the flow depth in an open Venturi channel. A ... -
Computational Fluid Dynamics Study of Shear Thinning Fluid (Drilling Fluid) Viscosity Models in an Open Venturi Channel
Welahettige, Prasanna Kumara Welahetti; Lie, Bernt; Vågsæther, Knut (Journal article; Peer reviewed, 2019)We aim to develop an improved kick/loss detection technology by developing smart flow-sensor technology for returned flow from the oil well in open Venturi channels. This is a detailed study about a capacity of use of ... -
Computational Fluid Dynamics Study of the Effects of Drill Cuttings on the Open Channel Flow
Welahettige, Prasanna Kumara Welahetti; Berg, Christian; Lundberg, Joachim; Lie, Bernt; Vågsæther, Knut (Peer reviewed; Journal article, 2019)A three-dimensional computational fluid dynamics (CFD) study was carried out for drilling fluid flow with drill cuttings in open channels. The flow is similar to the return flow when drilling, stream containing drilling ... -
Detonation propagation in stratified reactant layers
Gaathaug, André Vagner; Bjerketvedt, Dag; Lundberg, Joachim; Vågsæther, Knut (Journal article; Peer reviewed, 2017)A numerical investigation of detonation propagation in stratified reactant layers is presented in this paper. It is baesed on the reactive Euler equations using a two step chemical kinetics approach. The numerical simulations ... -
Evaporation characteristics during decompression of liquified CO2 from a conical-shaped vessel
Ibrahim, Osama Kabbashi M.; Hansen, Per Morten; Bjerketvedt, Dag; Vågsæther, Knut (Peer reviewed; Journal article, 2021)Safe transport of pressurized CO2 requires a profound knowledge of the processes' effect during the phase transition on catastrophic failure of a tanker filled with liquid CO2. This study presents experimental results and ... -
Experimental Study of Gas Explosions in Hydrogen Sulfide-Natural Gas-Air Mixtures
Gaathaug, André Vagner; Bjerketvedt, Dag; Vågsæther, Knut; Nilsen, Sandra Hennie (Journal article; Peer reviewed, 2014-08-21)An experimental study of turbulent combustion of hydrogen sulfide (H2S) and natural gas was performed to provide reference data for verification of CFD codes and direct comparison. Hydrogen sulfide is present in most crude ... -
Experimental study of primary atomization characteristics of sonic air-assist atomizers
Sikka, Raghav; Vågsæther, Knut; Bjerketvedt, Dag; Lundberg, Joachim (Journal article; Peer reviewed, 2021)The present study compares two twin-fluid atomizer concepts based on the airflow (shock waves) pattern obtained through shadowgraph imaging for atomization of water with a low air/water pressure supply. The research work ... -
Experiments with flame propagation in a channel with one obstacle and premixed H2-air
Gaathaug, André Vagner; Bjerketvedt, Dag; Vågsæther, Knut (Conference object; Peer reviewed, 2009-07)This abstract presents experimental results of flame propagation in a square channel with a single obstacle. The background for the experimental study was to investigate how a flame propagated when and after the flame ... -
Explosion characteristics for Li-ion battery electrolytes at elevated temperatures
Henriksen, Mathias; Vågsæther, Knut; Lundberg, Joachim; Forseth, Sissel; Bjerketvedt, Dag (Peer reviewed; Journal article, 2019)Li-ion batteries are used in electronic devices and electric cars, yet they create safety concerns due to the possibility of the release of combustible materials. The electrolyte, one of the main components in a Li-ion ... -
Flow regime changes at hydraulic jumps in an open Venturi channel for Newtonian fluid
Welahettige, Prasanna Kumara Welahetti; Lie, Bernt; Vågsæther, Knut (Journal article; Peer reviewed, 2017) -
Hydrodynamics - calculation of added mass on complex objects
Kaasa, Sondre (Master thesis, 2021)Added mass er et komplekst fenomen innen hydrodynamikk, hvor det finnes lite forståelse i industrien. Dermed var motivasjonen for dette arbeidet å bygge kunnskap innen hydrodynamikk og numerisk modellering av hydrodynamiske ... -
Investigation of the performance of a pilotscale CO2 desorption column using CFD simulations
Shakeri, Avishan (Master thesis, 2021)Technology Center Mongstad (TCM) is the world’s largest and most flexible test facility for amine based CO2 absorption and desorption. This master thesis is based on an operational problem at TCM where excess liquid loading ...