Browsing NTNU Open by Author "Nordam, Tor"
Now showing items 1-20 of 39
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A comparison of two parallel solution schemes for the advection-diffusion equation - Velocity guided random walk of paticles vs finite volume discretization on Cartesian grid
Pedersen, Fredrik (Master thesis, 2017)In this thesis two methods for solving the diffusion-advection equation was implemented using MPI. The two methods was a velocity guided random walk of particles and solving the advection-diffusion equation on a grid. Both ... -
A Fast Simulation Method for Ultrasonic Wave Propagation in Coupled Non-parallel Plates
Arnestad, Håvard Kjellmo (Master thesis, 2021)Enkelte systemer i ultralydtesting kan tilnærmes som to ikke-parallelle plater koblet med et fluid, der utstrålende Lamb-bølger brer seg ut i hver plate. Denne oppgaven utvikler en rask og nøyaktig simuleringsmetode for ... -
Advancing Ocean Observation with an AI-driven Mobile Robotic Explorer
Saad, Aya; Stahl, Annette; Våge, Andreas; Davies, Emlyn John; Nordam, Tor; Aberle-Malzahn, Nicole; Ludvigsen, Martin; Johnsen, Geir; Sousa, João; Rajan, Kanna (Journal article; Peer reviewed, 2020)Rapid assessment and enhanced knowledge of plankton communities and their structure in the productive upper water column is of crucial importance to understand the impact of the changing climate on upper ocean processes. ... -
Analysis of Integration Architecture in Integrated Environmental Monitoring System - Development of Front-End Prototype for Decision Support for Drilling in Areas with Sensitive Fauna
Torgersen, Therese (Master thesis, 2017)This master's thesis is a continuation of the specialization project, which focused on the underlying need for better surveillance of sensitive fauna, during drilling operation, and an industry developed software solution ... -
Boundary artifact analysis in diffusion modelling with stochastic differential equations
Yip, Mauhing (Master thesis, 2019)In many research areas, it is common to model advection-diffusion problems with Lagrangian particle methods. This is the same as solving a stochastic differential equation, with drift and diffusion coefficients derived ... -
Climate Change and Fate of Arctic Oil Spills
Nordam, Tor; Beegle-Krause, Cynthia Juyne; Reed, Mark (Chapter, 2017)To investigate how the fate of oil released in the Arctic Ocean may change with a warmer climate, we have performed ensembles of oil spill simulations using Arctic environmental information (winds, currents, ice cover, ... -
A comparison of Eulerian and Lagrangian methods for vertical particle transport in the water column
Nordam, Tor; Kristiansen, Ruben; Nepstad, Raymond; van Sebille, Erik; Booth, Andy (Journal article, 2023)A common task in oceanography is to model the vertical movement of particles such as microplastics, nanoparticles, mineral particles, gas bubbles, oil droplets, fish eggs, plankton, or algae. In some cases, the distribution ... -
Computing Hyperbolic Lagrangian Coherent Structures in Three-Dimensional Flow Systems
Løken, Arne Magnus Tveita (Master thesis, 2018)A generic flow system can be described as a system whose state depends on flowing streams of energy, material, or information. Traditional examples of such systems are the transport of properties such as pressure, temperature, ... -
Computing hyperbolic Lagrangian coherent structures in three-dimensional flows from their variational theory
Nordgreen, Simon (Master thesis, 2018)Lagrangian coherent structures (LCSs) are dynamic surfaces that shape the flow patterns in complex transport systems. Accurate identification of LCSs has applications in particle transport, including dissemination of oil ... -
Convergence of Ensemble Simulations for Environmental Risk Assessment
Nordam, Tor; Brönner, Ute; Daae, Ragnhild Lundmark (Chapter, 2017)Ensemble simulations of oil fate and transport for a hypothetical oil spill, sometimes referred to as "stochastic simulations", are frequently used for environmental risk assessment related to offshore operations. In this ... -
Effects of chemical dispersants on feathers from Arctic seabirds
Fritt-Rasmussen, Janne; Linnebjerg, Jannie Fries; Nordam, Tor; Rigét, Frank F.; Kristensen, Paneeraq; Skancke, Jørgen; Wegeberg, Susse; Mosbech, Anders; Gustavson, Kim (Journal article; Peer reviewed, 2023)Chemical dispersion is an oil spill response strategy where dispersants are sprayed onto the oil slick to enhance oil dispersion into the water. However, accidental application could expose seabirds to dispersants, thereby ... -
Experimental and numerical studies of the scattering of light from a two-dimensional randomly rough interface in the presence of total internal reflection: Optical Yoneda peaks
Gonzalez-Alcalde, A. K.; Banon, Jean-Philippe; Hetland, Øyvind Storesund; Maradudin, Alexei A.; Mendez, Eugenio; Nordam, Tor; Simonsen, Ingve (Journal article; Peer reviewed, 2016)The scattering of polarized light from a dielectric film sandwiched between two different semi-infinite dielectric media is studied experimentally and theoretically. The illuminated interface is planar, while the back ... -
The fate of hydrocarbon leaks from plugged and abandoned wells by means of natural seepages
Tveit, Mari Røstvig; Khalifeh, Mahmoud; Nordam, Tor; Saasen, Arild (Peer reviewed; Journal article, 2020)When a well reaches the end of its productive life, it is permanently plugged and abandoned. Even though new technology and verification methods are being evaluated, it is evident that operational, barrier material and ... -
Handling Discontinuities in Numerical ODE Methods
Mørk, Jenny Margareta (Master thesis, 2021)Et vanlig ønske i mange typer arbeid er å finne den fremgangsmåten som gir best resultat uten å kreve for mye innsats. For eksempel så krever modellering av hvordan forurensende stoffer sprer seg i havet at man beregner ... -
High-resolution numerical modelling of a marine mine tailings discharge in Western Norway
Nepstad, Raymond; Muñoz, Maria Liste; Alver, Morten; Nordam, Tor; Davies, Emlyn John; Glette, Tormod (Peer reviewed; Journal article, 2020)Waste from mining operations includes mine tailings, a slurry of fine-grained mineral particles and processing chemicals that remains after the desired compounds have been extracted from the ore. In some cases, the method ... -
Identifying Lagrangian Coherent Structures Using Clustering
Skagestad, Andreas Bjerke (Master thesis, 2018)In these times of rapid environmental changes, our understanding of nature becomes ever more crucial. For example, the spread of oil spills and microplastics can have far reaching consequences for the ecology. Previous ... -
An impact-based environmental risk assessment model toolbox for offshore produced water discharges
Nepstad, Raymond; Kotzakoulakis, Konstantinos; Hansen, Bjørn Henrik; Nordam, Tor; Carroll, JoLynn (Peer reviewed; Journal article, 2023)We present a novel approach to environmental risk assessment of produced water discharges based on explicit impact and probability, using a combination of transport, fate and toxicokinetic-toxicodynamic models within a ... -
Implementing and reviewing a published cellular automaton model for simulating erosion and deposition processes due to turbidity currents
Gundersen, Steinar Brattøy (Master thesis, 2019)Gruveindustrien har i lengre tid benyttet seg av sjødeponi for lagring av "tailings". I slike sjødeponi er det vanlig at turbiditetsstrømmer oppstår som følge av utslippet, hvilket medfører at partiklene fraktes en lengre ... -
Introducing CoSTA: A Deep Neural Network Enabled Approach to Improving Physics-Based Numerical Simulations
Blakseth, Sindre Stenen (Master thesis, 2021)Hybrid analyse og modellering (HAM) er et fremvoksende modelleringsparadigme hvor fysikkbasert modellering (FBM) og datadreven modellering (DDM) kombineres for å utvikle modeller som er generaliserbare, pålitelige, nøyaktige, ... -
Lagrangian methods and density estimation for advection-diffusion problems
Rikardsen, Edel Sofie Ulvåg (Master thesis, 2021)Denne oppgaven undersøker numerisk transport i to dimensjoner i et periodisk dobbel-vortex strømningsfelt som presentert i Shadden et al. (2005) med konstant diffusjon, gjennom å benytte både eulerske og lagrangske metoder. ...