Blar i NTNU Open på forfatter "Johansen, Stein Tore"
-
Judging the Generalized Newtonian Fluid assumption for cuttings transport modelling by applying time scale comparisons
Busch, Alexander; Johansen, Stein Tore (Chapter, 2018)Cellulose (PAC) solutions are often employed as drilling fluid model systems in experimental laboratory studies to investigate cuttings transport. For this purpose, PAC solutions are typically assumed to behave purely ... -
Membrane-Assisted Chemical Switching Reforming for pure hydrogen production with integrated CO2 capture
Wassie, Solomon Assefa (Doctoral theses at NTNU;2018:217, Doctoral thesis, 2018)Concerns regarding the anthropogenic greenhouse gas emissions on climate change have drawn substantial research efforts to develop new technologies that can mitigate or, if possible, eliminate anthropogenic emissions of ... -
Modelling and Measuring Transient Flow in Natural Gas Pipelines: Effect of Ambient Heat Transfer Models
Oosterkamp, Antonie (Doctoral thesis at NTNU;2016:163, Doctoral thesis, 2016)The central question of this thesis is how and to what extent the representation of ambient heat transfer in the calculation models contributes to observed deviations between modelled and measured flow parameters in natural ... -
Modelling of dispersed oil/water flow in a near-horizontal pipe
Kjølaas, Jørn; Schümann, Heiner; Gonzalez Rengifo, Diana Carolina; Johansen, Stein Tore (Journal article; Peer reviewed, 2022)A gravity-diffusion model was implemented for predicting water concentration profiles in dispersed oil-continuous oil–water flows. In this model, the measured droplet size distributions were used instead of a droplet size ... -
Modelling of the Transient Pressure Build-up in Long Wellbores
Sissener, Olaf Hedberg (Master thesis, 2015)Drilling of long oil wells becomes increasingly more common in the oil and gas industry, as cost rises and complexity of undrilled reservoirs increases. This introduces a challenge that grow in severity with the length of ... -
New Insights into the Modeling of Energy Generation and Storage by Salinity Gradients
Jalili, Zohreh (Doctoral theses at NTNU;2021:25, Doctoral thesis, 2020) -
Numerical approach for generic three‐phase flow based on cut‐cell and ghost fluid methods
Dang, Son Tung; Meese, Ernst A.; Morud, John; Johansen, Stein Tore (Peer reviewed; Journal article, 2019)In this paper, we introduce numerical methods that can simulate complex multiphase flows. The finite volume method, applying Cartesian cut‐cell is used in the computational domain, containing fluid and solid, to conserve ... -
On particle transport and turbulence in wellbore flows of non-Newtonian fluids - Findings from a cuttings transport process analysis by means of computational fluid dynamics, rheometry, and dimensional analysis
Busch, Alexander (Doctoral theses at NTNU;2020:95, Doctoral thesis, 2020)Cuttings transport modeling was analyzed with a major focus on three dimensional (3D) Computational Fluid Dynamics (CFD) approaches including rheometry and to a lesser extent on one-dimensional modeling and dimensional ... -
On the validity of the two-fluid-KTGF approach for dense gravity-driven granular flows as implemented in ANSYS Fluent R17.2
Busch, Alexander; Johansen, Stein Tore (Peer reviewed; Journal article, 2020)As a subproblem of solid transport in wellbores, we have investigated the cliff collapse problem by means of the Two-Fluid-Model (TFM), where the rheological description of the second phase (sand) is governed by the Kinetic ... -
Performance evaluation of a complete Lagrangian KTGF approach for dilute granular flow modelling
Cloete, Schalk; Johansen, Stein Tore; Amini, Shahriar (Journal article; Peer reviewed, 2012)Finely resolved gas–solid flow simulations were carried out using an improved Lagrangian method known as the dense discrete phase model (DDPM). The DDPM differs from the traditional Eulerian two fluid model (TFM) approach ... -
A Pragmatic Model for Alumina Feeding
Johansen, Stein Tore; Einarsrud, Kristian Etienne; Solheim, Asbjørn; Vachaparambil, Kurian J. (Peer reviewed; Journal article, 2022)In this paper, we demonstrate how we can develop a coarse-grained model for the alumina distribution in an aluminium reduction cell. The model is designed to have the potential of being a part of a control system or play ... -
A Pragmatic Model for Bath Temperature Evolution During Alumina Feeding
Vachaparambil, Kurian J.; Johansen, Stein Tore; Solheim, Asbjørn; Einarsrud, Kristian Etienne (Peer reviewed; Journal article, 2023)In this paper, we extend the pragmatic model for alumina feeding, presented in Johansen et al. Light metals 2022, to treat the associated evolution of bath temperature. The underlying idea of the framework is to reduce its ... -
Rheological characterization of Polyanionic Cellulose solutions with application to drilling fluids and cuttings transport modeling
Busch, Alexander; Myrseth, Velaug; Khatibi, Milad; Skjetne, Paal; Hovda, Sigve; Johansen, Stein Tore (Journal article; Peer reviewed, 2018)In petroleum drilling, aqueous Polyanionic Cellulose solutions (PAC) are often used as a drilling fluid model system in experimental laboratory studies to investigate cuttings transport. Cuttings transport refers to the ... -
Simulation and Evaluation of Slurry Erosion
Strømme, Erik Grimm (Master thesis, 2015)Erosion from sand particles is a large problem in piping systems, especially in the oil and gas industries. Different types of erosion occur depending on the concentration of particles present in the fluid. Computational ... -
Soft: a framework for semantic interoperability of scientific software
Hagelien, Thomas Fjæstad; Chesnokov, Andrey; Johansen, Stein Tore; Meese, Ernst A.; Løvfall, Bjørn Tore (Chapter, 2017)In this paper we present our strategy and implementation of a datacentric modelling framework (SOFT, SINTEF Open Framework and Tools) with focus on information interchange in throughprocess and multiscale applications. ... -
The effect of frictional pressure, geometry and wall friction on the modelling of a pseudo-2D bubbling fluidised bed reactor
Cloete, Schalk Willem Petrus; Johansen, Stein Tore; Zaabout, Abdelghafour; van Sint Annaland, Martin; Gallucci, Fausto; Amini, Shahriar (Journal article; Peer reviewed, 2015)The two fluid model (TFM) closed by the kinetic theory of granular flows (KTGF) has been developed to a high level of maturity over the past three decades. However, significant uncertainties still remain about the influence ... -
The generality of the standard 2D TFM approach in predicting bubbling fluidized bed hydrodynamics
Cloete, Schalk Willem Petrus; Zaabout, Abdelghafour; Johansen, Stein Tore; Annaland, MV; Gallucci, F; Amini, Shahriar (Journal article; Peer reviewed, 2013)Hydrodynamic simulations of a pseudo-2D bubbling fluidized bed were carried out and compared to experiments conducted over a wide range of flow conditions. The primary purpose of this study was to assess the generality of ... -
Transient dynamikk i gasstransport
Lyssand, Torbjørn (Master thesis, 2011)Beregningsmodeller som i dag brukes til prediksjon og overvåkning av gasstransport, er stort sett basert på 1 dimensjonale betraktninger. Friksjonsfaktoren som brukes i disse modellene er gjerne av typen Colebrook-White, ...