Blar i NTNU Open på forfatter "Munkejord, Svend Tollak"
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A robust method for calculating interface curvature and normal vectors using an extracted local level set
Ervik, Åsmund; Lervåg, Karl Yngve; Munkejord, Svend Tollak (Journal article, 2014)The level-set method is a popular interface tracking method in two-phase flow simulations. An often-cited reason for using it is that the method naturally handles topological changes in the interface, e.g. merging drops, ... -
An experimental investigation of liquid droplets impinging vertically on a deep liquid pool
Zhao, He (Doctoral Theses at NTNU, 1503-8181; 2009:230, Doctoral thesis, 2009)Interactions between droplets and liquid films are found widely in our daily life, and many interesting phenomena can be observed. Scientists study the phenomena not only because they are fascinating but also apply the ... -
An experimental method for studying the discrete droplet impact phenomena in a flammable gas environment
Zhao, He; Brunsvold, Amy; Munkejord, Svend Tollak; Mølnvik, Mona J. (Journal article; Peer reviewed, 2010)To improve the initial design as well as to gain insight into operational issues of heat exchangers and other process equipment involving complex two-phase flow phenomena, one can choose to conduct full-scale ... -
An exponential time-differencing method for monotonic relaxation systems
Aursand, Peder; Evje, Steinar; Flåtten, Tore; Teigen, Knut Erik; Munkejord, Svend Tollak (Journal article; Peer reviewed, 2014)We present first and second-order accurate exponential time differencing methods for a special class of stiff ODEs, denoted as monotonic relaxation ODEs. Some desirable accuracy and robustness properties of our methods are ... -
Analysis of the two-fluid model and the drift-flux model for numerical calculation of two-phase flow
Munkejord, Svend Tollak (Doktoravhandlinger ved NTNU, 1503-8181; 2005:219, Doctoral thesis, 2006)Flerfasestrømning er av betydning i en lang rekke anvendelser, blant annet i olje- og gassindustrien, i den kjemiske og i prosessindustrien, inkludert i varmepumpende systemer, samt i sikkerhetsanalyse av kjernekraftverk. ... -
Calculation of the interface curvature and normal vector with the level-set method
Lervåg, Karl Yngve; Müller, Bernhard; Munkejord, Svend Tollak (Journal article, 2013)This article addresses the use of the level-set method for capturing the interface between two fluids. One of the advantages of the level-set method is that the curvature and the normal vector of the interface can be readily ... -
CO2 pipeline integrity: A coupled fluid-structure model using a reference equation of state for CO2
Aursand, Eskil; Aursand, Peder; Berstad, Torodd; Dørum, Cato; Hammer, Morten; Munkejord, Svend Tollak; Nordhagen, Håkon Ottar (Journal article; Peer reviewed, 2013)We present a coupled fluid-structure model to study crack propagation and crack arrest in pipelines. Numerical calculations of crack arrest, crack velocity and pressure profiles have been performed for steel pipes with an ... -
CO2 pipeline integrity: A new evaluation methodology
Berstad, Torodd; Dørum, Cato; Jakobsen, Jana Poplsteinova; Kragset, Steinar; Li, Hailong; Lund, Halvor; Morin, Alexandre; Munkejord, Svend Tollak; Mølnvik, Mona Jacobsen; Nordhagen, Håkon Ottar; Østby, Erling (Journal article; Peer reviewed, 2011)A coupled fluid-structure model for pipeline integrity simulations has been developed. The pipe material and fracture propagation have been modelled using the finite-element method with a local fracture criterion. The ... -
Depressurization of CO2 in pipes: Analysis of experiments and non-equilibrium flashing flow models
Log, Alexandra Metallinou (Doctoral theses at NTNU;2023:427, Doctoral thesis, 2023)CO2 capture and storage is expected to play a vital role in reaching net zero emissions by 2050. In this context, large-scale CO2 pipeline transportation networks must be deployed. In order to perform safety analyses and ... -
Depressurization of in a pipe: Effect of initial state on non-equilibrium two-phase flow
Log, Alexandra Metallinou; Hammer, Morten; Deng, Han; Austegard, Anders; Hafner, Armin; Munkejord, Svend Tollak (Peer reviewed; Journal article, 2023)It is key in several industrial applications to accurately describe rapid depressurization of liquid and dense phase states. Examples include refrigeration systems, nuclear reactor cooling and capture and storage (CCS). ... -
Development and investigation of HLLC-type finite-volume methods for one and two-phase flow in pipes with varying cross-sectional area.
Log, Alexandra Metallinou (Master thesis, 2020)I dette arbeidet er den numeriske løseren Harten-Lax van Leer Contact (HLLC) utvidet for å anvendes på strømning i rør med varierende tverrsnitt. I tillegg blir den homogene likevekts-tofasemodellen (HEM) løst av HLLC for ... -
Development of an immersed boundary method for simulating contaminated fluid interfaces in two-phase flow
Lysgaard, Morten Olsen (Master thesis, 2015)This thesis covers the theory and implementation, verification and validation of an immersed boundary method for simulating the effect of an elastic membrane covering water drops in crude oil. First an introduction to ... -
Experimental and computational studies of water drops falling through model oil with surfactant and subjected to an electric field
Ervik, Åsmund; Hellesø, Svein Magne; Munkejord, Svend Tollak; Müller, Bernhard (Chapter, 2014)The behaviour of a single sub-millimetre-size water drop falling through a viscous oil while subjected to an electric field is of fundamental importance to industrial applications such as crude oil electrocoalescers. ... -
Experiments and modelling of choked flow of CO2 in orifices and nozzles
Hammer, Morten; Deng, Han; Austegard, Anders; Log, Alexandra Metallinou; Munkejord, Svend Tollak (Peer reviewed; Journal article, 2022)In order to accelerate the deployment of capture and storage (CCS), engineers need experimentally validated models, among other things, to predict the mass flow rate in process equipment and flow restrictions like valves, ... -
A flashing flow model for the rapid depressurization of CO2 in a pipe accounting for bubble nucleation and growth
Log, Alexandra Metallinou; Hammer, Morten; Munkejord, Svend Tollak (Peer reviewed; Journal article, 2023)Flashing flow is encountered in many industrial systems involving nozzles, valves and decompression of vessels and pipes. In the context of CO2 capture and storage (CCS), the design of safe and efficient CO2 transportation ... -
Frictional Pressure Drop for Two-phase Flow of Carbon Dioxide in a Tube: Comparison between Models and Experimental Data
Aakenes, Frøydis; Munkejord, Svend Tollak; Drescher, Michael (Journal article; Peer reviewed, 2014)We compare models for two-phase frictional pressure drop with experimental data for pure CO2 taken in a tube of 10 mm inner diameter. The flow was nearly adiabatic, and the mass fluxes ranged from 1058 to 1663 kg/(m2 s), ... -
Frictional pressure-drop models for steady-state and transient two-phase flow of carbon dioxide
Aakenes, Frøydis (Master thesis, 2012)Related to the technology of CO2 capture, transport, and storage (CCS), an accurate transport model which predicts the behaviour of carbon-dioxide mixtures during steady-state and transient situations, is needed. A correct ... -
HLLC-type methods for compressible two-phase flow in ducts with discontinuous area changes
Log, Alexandra Metallinou; Munkejord, Svend Tollak; Hammer, Morten (Peer reviewed; Journal article, 2021)In this work, the Harten-Lax-van Leer Contact (HLLC) approximate Riemann solver is extended to two-phase flow through ducts with discontinuous cross-sections. Two main strategies are explored regarding the treatment of the ... -
Hyperbolic Conservation Laws with Relaxation Terms: A Theoretical and Numerical Study
Aursand, Peder Kristian (Master thesis, 2011)Hyperbolic relaxation systems is an active field of research, with a largenumber of applications in physical modeling. Examples include modelsfor traffic flow, kinetic theory and fluid mechanics. This master s thesis is ... -
Influence of surfactants on the electrohydrodynamic stretching of water drops in oil
Ervik, Åsmund; Penne, Torstein Eidsnes; Hellesø, Svein Magne; Munkejord, Svend Tollak; Müller, Bernhard (Journal article; Peer reviewed, 2017)In this paper we present experimental and numerical studies of the electrohydrodynamic stretching of a sub-millimetre-sized salt water drop, immersed in oil with added non-ionic surfactant, and subjected to a suddenly ...