Browsing NTNU Open by Author "Aasen, Ailo"
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A Study of Rotational Water Waves using Bifurcation Theory
Aasen, Ailo (Master thesis, 2014)This thesis is concerned with the water wave problem. Using local bifurcation we establish small-amplitude steady and periodic solutions of the Euler equations with vorticity. Our approach is based on that of Ehrnström, ... -
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 ... -
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) -
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 ... -
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 ... -
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 ... -
Equation of state and force fields for Feynman-Hibbs-corrected Mie fluids. II. Application to mixtures of helium, neon, hydrogen and deuterium
Aasen, Ailo; Hammer, Morten; Müller, Erich; Wilhelmsen, Øivind (Peer reviewed; Journal article, 2020)We extend the statistical associating fluid theory of quantum corrected Mie potentials (SAFT-VRQ Mie), previously developed for pure fluids [Aasen et al., J. Chem. Phys. 151, 064508 (2019)], to fluid mixtures. In this ... -
Equation of state and force fields for Feynman–Hibbs-corrected Mie fluids. I.Application to pure helium, neon, hydrogen, and deuterium
Aasen, Ailo; Hammer, Morten; Ervik, Åsmund; Müller, Erich A.; Wilhelmsen, Øivind (Journal article; Peer reviewed, 2019)We present a perturbation theory that combines the use of a third-order Barker–Henderson expansion of the Helmholtz energy with Miepotentials that include first- (Mie-FH1) and second-order (Mie-FH2) Feynman–Hibbs quantum ... -
Equation of state for confined fluids
Bråten, Vilde; Zhang, Daniel Tianhou; Hammer, Morten; Aasen, Ailo; Schnell, Sondre Kvalvåg; Wilhelmsen, Øivind (Peer reviewed; Journal article, 2022)Fluids confined in small volumes behave differently than fluids in bulk systems. For bulk systems, a compact summary of the system's thermodynamic properties is provided by equations of state. However, there is currently ... -
Estimating metastable thermodynamic properties by isochoric extrapolation from stable states
Aasen, Ailo; Hammer, Morten; Reguera, David; Wilhelmsen, Øivind (Journal article; Peer reviewed, 2024)The description of metastable fluids, those in local but not global equilibrium, remains an important problem of thermodynamics, and it is crucial for many industrial applications and all first order phase transitions. One ... -
Free energy of critical droplets - From the binodal to the spinodal
Aasen, Ailo; Wilhelmsen, Øivind; Hammer, Morten; Reguera, David (Peer reviewed; Journal article, 2023)Arguably, the main challenge of nucleation theory is to accurately evaluate the work of formation of a critical embryo in the new phase, which governs the nucleation rate. In Classical Nucleation Theory (CNT), this work ... -
Ice formation and growth in supercooled water–alcohol mixtures: Theory and experiments with dual fiber sensors
Wahl, Markus Solberg; Aasen, Ailo; Hjelme, Dag Roar; Wilhelmsen, Øivind (Peer reviewed; Journal article, 2020)Increased knowledge on fluid-solid phase transitions is needed, both when they are undesired and can impair processes operation, and when strict control is required in fields such as food technology, the pharmaceutical ... -
One-dimensional mathematical modeling of two-phase ejectors: Extension to mixtures and mapping of the local exergy destruction
Wilhelmsen, Øivind; Aasen, Ailo; Banasiak, Krzysztof; Herlyng, Halvor; Hafner, Armin (Peer reviewed; Journal article, 2022)The ejector is a process equipment frequently used in refrigeration processes. There is currently a knowledge gap on the efficiency of ejectors operating with mixtures. To address this knowledge gap, we present a one-dimensional ... -
Optimization of Pipe Geometries with Entropy Production Minimization in Viscous Flow
Herlyng, Halvor (Master thesis, 2022)Hvordan termodynamiske irreversibiliteter i strømningen i ejektorer kan reduseres og hvordan optimalt design av ejektorer skal utføres er enda ikke helt forstått. Ejektorer er utstyr som brukes i forskjellige energiprosesser ... -
Reducing the exergy destruction in the cryogenic heat exchangers of hydrogen liquefaction processes
Wilhelmsen, Øivind; Berstad, David Olsson; Aasen, Ailo; Nekså, Petter; Skaugen, Geir (Journal article; Peer reviewed, 2018)A present key barrier for implementing large-scale hydrogen liquefaction plants is their high power consumption. The cryogenic heat exchangers are responsible for a significant part of the exergy destruction in these plants ... -
Thermodynamic modeling with equations of state: present challenges with established methods
Wilhelmsen, Øivind; Aasen, Ailo; Skaugen, Geir; Aursand, Peder; Austegard, Anders; Aursand, Eskil; Gjennestad, Magnus Aashammer; Lund, Halvor; Linga, Gaute; Hammer, Morten (Journal article; Peer reviewed, 2017)Equations of state (EoS) are essential in the modeling of a wide range of industrial and natural processes. Desired qualities of EoS are accuracy, consistency, computational speed, robustness and predictive ability outside ... -
Thermodynamic models to accurately describe the PVTxy-behavior of water / carbon dioxide mixtures
Aasen, Ailo; Hammer, Morten; Skaugen, Geir; Jakobsen, Jana Poplsteinova; Wilhelmsen, Øivind (Journal article; Peer reviewed, 2017)Carbon dioxide/water (CO2/H2O) mixtures are of much interest in carbon capture and storage, atmospheric science, in the description of human lungs and in the processing of food and beverages. We present a comprehensive ... -
Thermodynamic properties of the 3D Lennard-Jones/spline model
Hafskjold, Bjørn; Travis, Karl; Bailey, Amanda H.; Hammer, Morten; Aasen, Ailo; Wilhelmsen, Øivind (Peer reviewed; Journal article, 2019)In the Lennard-Jones spline (LJ/s) model, the Lennard-Jones (LJ) potential is truncated and splined so that both the pair potential and the force continuously approach zero at rc ≈ 1.74σ. It exhibits the same structural ...