Browsing NTNU Open by Author "Wilhelmsen, Øivind"
Now showing items 1-20 of 81
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A consistent reduction of the two-layer shallow-water equations to an accurate one-layer spreading model
Fyhn, Eirik Holm; Lervåg, Karl Yngve; Ervik, Åsmund; Wilhelmsen, Øivind (Journal article; Peer reviewed, 2019)The gravity-driven spreading of one fluid in contact with another fluid is of key importance to a range of topics. These phenomena are commonly described by the two-layer shallow-water equations (SWE). When one layer is ... -
A Novel Experimental Setup for Measuring Corrosion Under Insulation with Electrochemical Noise Monitoring
Ulrichsen, Christian (Master thesis, 2024)Corrosion is a prominent field of interest across many industries, and corrosion under insulation (CUI) can be particularly challenging to detect and assess. Not only is visible detection hindered by the insulation material ... -
A Study of the Entropy Production in Liquid Phase Shock Waves
Maltby, Tage Winther (Master thesis, 2022)Vi har simulert en sjokkbølge i væskefase ved bruk av Non-Equilibrium Molecular dynamics (NEMD) og Navier-Stokes (N-S) ligningene. Den nye anvendelsen av N-S ligningene kombinerte en tilstandslikning (EOS) for et ... -
Accurate quantum-corrected cubic equations of state for helium, neon, hydrogen, deuterium and their mixtures
Aasen, Ailo; Hammer, Morten; Lasala, Silvia; Jaubert, Jean-Noël; Wilhelmsen, Øivind (Journal article; Peer reviewed, 2020)Cubic equations of state have thus far yielded poor predictions of the thermodynamic properties of quantum fluids such as hydrogen, helium and deuterium at low temperatures. Furthermore, the shape of the optimal α functions ... -
Addressing Challenges in Fabricating Reflection-2 Based Fiber Optic Interferometers
Wahl, Markus Solberg; Wilhelmsen, Øivind; Hjelme, Dag Roar (Journal article; Peer reviewed, 2019)abrication of multimode fiber optic interferometers requires accurate control of certain parameters to obtain reproducible results. This paper evaluates the consequences of practical challenges in fabricating reflection-based, ... -
Bulk and interfacial thermodynamics of ammonia, water and their mixtures
Aasen, Ailo; Jervell, Vegard Gjeldvik; Hammer, Morten; Strøm, Bjørn; Skarsvåg, Hans Langva; Wilhelmsen, Øivind (Journal article; Peer reviewed, 2024)Bulk and interfacial thermodynamics of ammonia, water and their mixtures -
Bulk and interfacial thermodynamics of mixtures: From aqueous systems to ultracryogenic fluids
Aasen, Ailo (Doctoral theses at NTNU;2020:38, Doctoral thesis, 2020) -
Chemical Potential Differences in the Macroscopic Limit from Fluctuations in Small Systems
Bråten, Vilde; Wilhelmsen, Øivind; Schnell, Sondre Kvalvåg (Peer reviewed; Journal article, 2021)We present a new method for computing chemical potential differences of macroscopic systems by sampling fluctuations in small systems. The small system method, presented by Schnell et al. [Schnell et al., J. Phys. Chem. ... -
Choice of reference, influence of non-additivity and present challenges in thermodynamic perturbation theory for mixtures
Hammer, Morten; Aasen, Ailo; Ervik, Åsmund; Wilhelmsen, Øivind (Peer reviewed; Journal article, 2020)This work revisits the fundamentals of thermodynamic perturbation theory for fluid mixtures. The choice of reference and governing assumptions can profoundly influence the accuracy of the perturbation theory. The statistical ... -
Choked liquid flow in nozzles: crossover from heterogeneous to homogeneous cavitation and insensitivity to depressurization rate
Wilhelmsen, Øivind; Aasen, Ailo (Peer reviewed; Journal article, 2021)The critical mass flow rate is the maximum flow rate that can pass through a constrained geometry such as a nozzle. For liquid CO2, it has been shown that homogeneous relaxation models systematically underpredict the ... -
Classical density functional theory for interfacial properties of hydrogen, helium, deuterium, neon and their mixtures
Hammer, Morten; Bauer, Gernot; Stierle, Rolf; Gross, Joachim; Wilhelmsen, Øivind (Peer reviewed; Journal article, 2023)The DFT is developed to study the interfacial properties of hydrogen, helium, neon, deuterium and their mixtures, i.e. fluids that are strongly influenced by quantum effects at low temperatures. White Bear fundamental ... -
A combined fluid-dynamic and thermodynamic model to predict the onset of rapid phase transitions in LNG spills
Lervåg, Karl Yngve; Skarsvåg, Hans Langva; Aursand, Eskil; Ouassou, Jabir Ali; Hammer, Morten; Reigstad, Gunhild Allard; Ervik, Åsmund; Fyhn, Eirik Holm; Gjennestad, Magnus Aashammer; Aursand, Peder; Wilhelmsen, Øivind (Peer reviewed; Journal article, 2020)Transport of liquefied natural gas (LNG) by ship occurs globally on a massive scale. The large temperature difference between LNG and water means LNG will boil violently if spilled onto water. This may cause a physical ... -
Combined temperature and RI sensor for exploring the phase transitions of ethanol solutions
Wahl, Markus Solberg; Wilhelmsen, Øivind; Hjelme, Dag Roar (Chapter, 2018)A fiber optic interferometer based on core diameter mismatch is used in reflection mode to study the behavior of ethanol solutions with regards to concentration dependent thermal properties and phase transitions. A method ... -
A comparative study of experiments and theories on steady-state evaporation of water
Rauter, Michael Tobias; Aasen, Ailo; Kjelstrup, Signe Helene; Wilhelmsen, Øivind (Journal article, 2022)A precise description of energy and mass transport across the liquid-vapor interface of water is central in dis- ciplines spanning from climatology to seawater desalination. We present a critical assessment of six recent ... -
Comparing exergy losses and evaluating the potential of catalyst-filled plate-fin and spiral-wound heat exchangers in a large-scale Claude hydrogen liquefaction process
Skaugen, Geir; Berstad, David Olsson; Wilhelmsen, Øivind (Peer reviewed; Journal article, 2020)Detailed heat exchanger designs are determined by matching intermediate temperatures in a large-scale Claude refrigeration process for liquefaction of hydrogen with a capacity of 125 tons/day. A comparison is made of ... -
Concepts for Large Scale Hydrogen Liquefaction Plants
Eckroll, Jørgen (Master thesis, 2017)The main objective of this thesis is to perform a technical-exergetic analysis of a large-scale hydrogen liquefaction system. The system boundary of the technical analysis is isolated to the precooling part of the overall ... -
Concepts for Large Scale Hydrogen Production
Jakobsen, Daniel; Åtland, Vegar (Master thesis, 2016)The objective of this thesis is to perform a techno-economic analysis of large-scale, carbon-lean hydrogen production in Norway, in order to evaluate various production methods and estimate a breakeven price level. Norway ... -
Cryogenic CO2 condensation and membrane separation of syngas for large-scale LH2 production
Berstad, David Olsson; Wilhelmsen, Øivind; Skjervold, Vidar T.; Nekså, Petter (Chapter, 2017)Liquid hydrogen (LH2) has the potential to become a global energy commodity analogous to liquefied natural gas (LNG) in the future. This will require LH2 production capacities of similar scale as for large-scale LNG plants. ... -
Curvature Corrections Remove the Inconsistencies of Binary Classical Nucleation Theory
Aasen, Ailo; Reguera, David; Wilhelmsen, Øivind (Peer reviewed; Journal article, 2020)The study of nucleation in fluid mixtures exposes challenges beyond those of pure systems. A striking example is homogeneous condensation in highly surface-active water-alcohol mixtures, where classical nucleation theory ... -
De Første Stegene mot en Perturbasjonsteori for Små Systemer
Zhang, Daniel Tianhou (Master thesis, 2020)Tilstandsligninger (EOS) utviklet gjennom perturbasjonsteori er kjent i litteraturen og kan være et nyttig verktøy for å modellere væskeoppførsel. Selv om populære perturbasjonsteorier av f.eks. Barker-Henderson (BH) ...