Blar i NTNU Open på forfatter "Hansen, Alex"
-
Effective Rheology of Bi-viscous Non-newtonian Fluids in Porous Media
Talon, Laurent; Hansen, Alex (Peer reviewed; Journal article, 2020)We model the flow of bi-viscous non-Newtonian fluids in porous media by a square lattice where the links obey a piece-wise linear constitutive equation. We find numerically that the flow regime, where the network transitions ... -
Effective rheology of immiscible two-phase flow in porous media consisting of random mixtures of grains having two types of wetting properties
Fyhn, Hursanay; Sinha, Santanu; Hansen, Alex (Peer reviewed; Journal article, 2023)We consider the effective rheology of immiscible two-phase flow in porous media consisting of random mixtures of two types of grains having different wetting properties using a dynamic pore network model under steady-state ... -
Effective rheology of two-phase flow in a capillary fiber bundle model
Roy, Subhadeep; Hansen, Alex; Sinha, Santanu (Journal article; Peer reviewed, 2019)We investigate the effective rheology of two-phase flow in a bundle of parallel capillary tubes carrying two immiscible fluids under an external pressure drop. The diameter of the tubes vary along the length which introduce ... -
Ensemble distribution for immiscible two-phase flow in porous media
Savani, Isha; Bedeaux, Dick; Kjelstrup, Signe; Vassvik, Morten; Sinha, Santanu; Hansen, Alex (Journal article, 2017)We construct an ensemble distribution to describe steady immiscible two-phase flow of two incompressible fluids in a porous medium. The system is found to be ergodic. The distribution is used to compute macroscopic flow ... -
Exploring Biopolymers by the Fibre Bundle Model
Indrehus, Sunniva (Master thesis, 2017)Bundles of polymeric chains in biological systems represent the analogue of macroscopic fibrous materials such as textile, wood or paper, scaled down to nanometric dimensions, and performing the same mechanical functions ... -
Felles publiseringstjeneste i UH-sektoren: Rapport fra arbeidsgruppe utnevnt av UHR-Bibliotek
Kolstrup, Gitte Solveig; Aspaas, Per Pippin; Hansen, Alex; Haugen, Ole-Jørgen; Karlstrøm, Henrik; Røeggen, Anders (Research report, 2021) -
Film flow dominated simultaneous flow of two viscous incompressible fluids through a porous medium
Aursjø, Olav; Erpelding, Marion; Tallakstad, Ken Tore; Flekkøy, Eirik Grude; Hansen, Alex; Måløy, Knut Jørgen (Journal article; Peer reviewed, 2014-11-19)We present an experimental study of two-phase flow in a quasi-two-dimensional porous medium. The two phases, a water-glycerol solution and a commercial food grade rapeseed/canola oil, having an oil to water-glycerol viscosity ... -
Flow-Area Relations in Immiscible Two-Phase Flow in Porous Media
Roy, Subhadeep; Sinha, Santanu; Hansen, Alex (Journal article; Peer reviewed, 2020)We present a theoretical framework for immiscible incompressible two-phase flow in homogeneous porous media that connects the distribution of local fluid velocities to the average seepage velocities. By dividing the pore ... -
Fluid Meniscus Algorithms for Dynamic Pore-Network Modeling of Immiscible Two-Phase Flow in Porous Media
Sinha, Santanu; Gjennestad, Magnus Aashammer; Vassvik, Morten; Hansen, Alex (Peer reviewed; Journal article, 2021)We present in detail a set of algorithms for a dynamic pore-network model of immiscible two-phase flow in porous media to carry out fluid displacements in pores. The algorithms are universal for regular and irregular pore ... -
Fracture networks in sea ice
Vevatne, Jonas Nesland; Rimstad, Eivind; Hope, Sigmund Mongstad; Korsnes, Reinert; Hansen, Alex (Journal article; Peer reviewed, 2014-04-16)Fracturing and refreezing of sea ice in the Kara sea are investigated using complex network analysis. By going to the dual network, where the fractures are nodes and their intersections links, we gain access to topological ... -
Fracturing of Optimal Paths in a Random Lattice
Voigt, Andre (Master thesis, 2011)The subject of this thesis is the study of the creation of fault lines in a random lattice, provoked by the successive failure of optimal paths. Using the recently developed Optimal Path Cracked model, we investigate how ... -
Hyperballistic Superdiffusion and Explosive Solutions to the Non-Linear Diffusion Equation
Flekkøy, Eirik Grude; Hansen, Alex; Baldelli, Beatrice (Peer reviewed; Journal article, 2021)By means of a particle model that includes interactions only via the local particle concentration, we show that hyperballistic diffusion may result. This is done by finding the exact solution of the corresponding non-linear ... -
Implications of Realistic Fracture Criteria on Crack Morphology
Skjetne, Bjørn; Hansen, Alex (Journal article; Peer reviewed, 2019)We study the effects realistic fracture criteria have on crack morphology obtained in numerical simulations with a stochastic discrete element method. Results are obtained with two criteria which are consistent with the ... -
In-plane Fracture Front Propagation in the Thin Plate Fiber Bundle Model
Vågan, Jørgen (Master thesis, 2016)A new history independent thin plate Fiber Bundle Model is derived in or- der to model in-plane material fracture. The model provides an easy way of studying the not yet fully understood fracture processing zone. Only ... -
Integration of Time Shift Data and Acoustic Impedance - And Complex Time-Lapse Imaging
Sletten, Karl Oskar (Master thesis, 2015)This thesis consists of several projects related to time-lapse seismic data from the Norne field. For the first part of this thesis, I have investigated methods for integration of the time shift data and the seismic ... -
Investigating the Local Load Sharing Fibre Bundle Model in Higher Dimensions
Kjellstadli, Jonas T. (Master thesis, 2015)We introduce a generalization of the history-independent local load sharing fibre bundle model that is valid in arbitrarily high dimensions, and study this model numerically in one to five dimensions. Simulations show ... -
Local dynamics of a randomly pinned crack front: a numerical study
Gjerden, Knut Skogstrand; Stormo, Arne; Hansen, Alex (Journal article; Peer reviewed, 2014)We investigate numerically the dynamics of crack propagation along a weak plane using a model consisting of fibers connecting a soft and a hard clamp. This bottom-up model has previously been shown to contain the competition ... -
Local statistics of immiscible and incompressible two-phase flow in porous media
Fyhn, Hursanay; Sinha, Santanu; Hansen, Alex (Peer reviewed; Journal article, 2023)We consider immiscible and incompressible two-phase flow in porous media under steady-state conditions using a dynamic pore network model. We focus on the fluctuations in a Representative Elementary Area (REA), with the ... -
Local versus Equal Load Sharing in the Fiber Bundle Model
Kjellstadli, Jonas Tøgersen (Doctoral theses at NTNU;2019:368, Doctoral thesis, 2019)Fracture is a huge field of research that includes physics, geology, materials science, and engineering. Most approaches are very specialized, but what if we instead want to focus on the big picture to look for general ... -
Miscibility of ionic and neutral fluids in low dimensional systems: A computational investigation of room temperature ionic liquids / hydrocarbon mixtures
Berge, Andreas Greaker (Master thesis, 2014)A new class of organic ionic compounds, liquid at ambient conditions and collectively known as room temperature ionic liquids (RTIL) could represent the solvents of choice to extract hydrocarbons from pores and cracks in ...