Blar i NTNU Open på forfatter "Bedeaux, Dick"
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Local thermodynamic description of isothermal single-phase flow in porous media
Galteland, Olav; Rauter, Michael Tobias; Bratvold, Mina S.; Trinh, Thuat; Bedeaux, Dick; Kjelstrup, Signe (Journal article; Peer reviewed, 2022)Darcy's law for porous media transport is given a new local thermodynamic basis in terms of the grand potential of confined fluids. The local effective pressure gradient is determined using non-equilibrium molecular dynamics, ... -
Molecular alignment in molecular fluids induced by coupling between density and thermal gradients
Daub, Christopher David; Tafjord, Joakim; Kjelstrup, Signe; Bedeaux, Dick; Bresme, Fernando (Journal article; Peer reviewed, 2016)We investigate, using non-equilibrium molecular dynamics simulations and theory, the response of molecular fluids confined in slit pores under the influence of a thermal gradient and/or an applied force. The applied force ... -
Molecular Dynamics Simulations of Metal / Molten Alkali Carbonate Interfaces
Roest, D.L.; Ballone, P.A.; Bedeaux, Dick; Kjelstrup, Signe (Journal article, 2017)Neutral and charged interfaces between molten alkali carbonates M2CO3 (M = Li, Na, and K) and planar solid walls have been investigated by molecular dynamics based on a rigid-ions force field. Simulations cover the temperature ... -
Multi-component interfacial transport as described by the square gradient model: evaporation and condensation.
Glavatskiy, Kirill (Doktoravhandlinger ved NTNU, 1503-8181; 2009:176, Doctoral thesis, 2009)The aim of this thesis is to build a theoretical approach which allows to describe the behavior of fluid during evaporation and condensation in multicomponent systems. We consider isotropic non-polarizable mixtures. We ... -
Multi-component interfacial transport as described by the square gradient model: evaporation and condensation.
Glavatskiy, Kirill (Doktoravhandlinger ved NTNU, 1503-8181; 2009:176, Doctoral thesis, 2009)The aim of this thesis is to build a theoretical approach which allows to describe the behavior of fluid during evaporation and condensation in multicomponent systems. We consider isotropic non-polarizable mixtures. We ... -
Nanothermodynamic Description and Molecular Simulation of a Single-Phase Fluid in a Slit Pore
Galteland, Olav; Bedeaux, Dick; Kjelstrup, Signe (Peer reviewed; Journal article, 2021)We have described for the first time the thermodynamic state of a highly confined single-phase and single-component fluid in a slit pore using Hill’s thermodynamics of small systems. Hill’s theory has been named ... -
Non-isothermal transport of multi-phase fluids in porous media. Constitutive equations
Kjelstrup, Signe; Bedeaux, Dick; Hansen, Alex; Hafskjold, Bjørn; Galteland, Olav (Journal article; Peer reviewed, 2019)We define a representative elementary volume of a porous medium in terms of lumped extensive variables, including properties of homogeneous phases, interfaces, and contact lines. Using the grand potential, we define the ... -
Non-isothermal transport of multi-phase fluids in porous media; The entropy production
Kjelstrup, Signe; Bedeaux, Dick; Hansen, Alex; Hafskjold, Bjørn; Galteland, Olav (Journal article; Peer reviewed, 2018)We derive the entropy production for transport of multi-phase fluids in a non-deformable, porous medium exposed to differences in pressure, temperature, and chemical potentials. Thermodynamic extensive variables on the ... -
Nonequilibrium thermodynamics of surfaces captures the energy conversions in a shock wave
Hafskjold, Bjørn; Bedeaux, Dick; Kjelstrup, Signe; Wilhelmsen, Øivind (Peer reviewed; Journal article, 2020)A theory for the entropy production in a shock wave was developed using Gibbs’ excess properties in the framework of non-equilibrium thermodynamics (NET) of surfaces. The theory was used to analyze numerical results from ... -
Onsager-symmetry obeyed in athermal mesoscopic systems: Two-phase flow in porous media
Winkler, Mathias; Gjennestad, Magnus Aashammer; Bedeaux, Dick; Kjelstrup, Signe; Cabriolu, Raffaela; Hansen, Alex (Peer reviewed; Journal article, 2020)We compute the fluid flow time correlation functions of incompressible, immiscible two-phase flow in porous media using a 2D network model. Given a properly chosen representative elementary volume, the flow rate distributions ... -
Peltier effects in lithium-ion battery modeling
Spitthoff, Lena; Gunnarshaug, Astrid Fagertun; Bedeaux, Dick; Burheim, Odne Stokke; Kjelstrup, Signe (Peer reviewed; Journal article, 2021)A high battery temperature has been shown to be critical for lithium-ion batteries in terms of performance, degradation, and safety. Therefore, a precise knowledge of heat sources and sinks in the battery is essential. We ... -
Phase transitions in multicomponent systems at the nano-scale: the existence of a minimal bubble size
Wilhelmsen, Øivind; Bedeaux, Dick; Kjelstrup, Signe; Reguera, David (Journal article; Peer reviewed, 2014)The formation of nanoscale droplets/bubbles from a metastable bulk phase is still connected to many unresolved scientific questions. In this work we analyze the stability of multicomponent liquid droplets and bubbles in ... -
Pressures Inside a Nano-Porous Medium. The Case of a Single Phase Fluid
Galteland, Olav; Bedeaux, Dick; Hafskjold, Bjørn; Kjelstrup, Signe (Journal article; Peer reviewed, 2019)We define the pressure of a porous medium in terms of the grand potential and compute its value in a nano-confined or nano-porous medium, meaning a medium where thermodynamic equations need be adjusted for smallness. On ... -
Pressures inside a nano-porous medium. The case of a single phase fluid
Galteland, Olav; Kjelstrup, Signe; Bedeaux, Dick (Research report, 2018)We define the pressure of a porous medium in terms of the grand potential, and compute its value in a nano-confined or nano-porous medium, meaning a medium where thermodynamic equations need be adjusted for smallness. On ... -
Seebeck, Peltier, and Soret effects: On different formalisms for transport equations in thermogalvanic cells
Kjelstrup, Signe; Kristiansen, Kim Roger; Gunnarshaug, Astrid Fagertun; Bedeaux, Dick (Peer reviewed; Journal article, 2023)Thermogalvanic cells convert waste heat directly to electric work. There is an abundance of waste heat in the world and thermogalvanic cells may be underused. We discuss theoretical tools that can help us understand and ... -
Selectivity and self-diffusion of CO2 and H2 in a mixture on a graphite surface
Trinh, Thuat; Vlugt, Thijs J.H.; Hagg, May-Britt; Kjelstrup, Signe; Bedeaux, Dick (Journal article; Peer reviewed, 2013)We performed classical molecular dynamics (MD) simulations to understand the mechanism of adsorption from a gas mixture of CO2 and H2 (mole fraction of CO2 = 0.30) and diffusion along a graphite surface, with the aim to ... -
Size and shape effects on the thermodynamic properties of nanoscale volumes of water
Strøm, Bjørn; Simon, Jean-Marc; Schnell, Sondre Kvalvåg; Kjelstrup, Signe; He, Jianying; Bedeaux, Dick (Journal article; Peer reviewed, 2017)Small systems are known to deviate from the classical thermodynamic description, among other things due to their large surface area to volume ratio compared to corresponding big systems. As a consequence, extensive ... -
Small Size Effects in Open and Closed Systems: What Can We Learn from Ideal Gases about Systems with Interacting Particles?
Bråten, Vilde; Bedeaux, Dick; Wilhelmsen, Øivind; Schnell, Sondre Kvalvåg (Peer reviewed; Journal article, 2021)Small systems have higher surface area-to-volume ratios than macroscopic systems. The thermodynamics of small systems therefore deviates from the description of classical thermodynamics. One consequence of this is that ... -
The reversible heat effects at lithium iron phosphate- and graphite electrodes
Gunnarshaug, Astrid Fagertun; Kjelstrup, Signe; Bedeaux, Dick; Richter, Frank; Burheim, Odne Stokke (Journal article; Peer reviewed, 2019)Lithium ion batteries are used to store and produce electric energy. During the charging- and discharging processes, net heat is released or adsorbed in the battery. Temperature is one of the most important factors for ... -
Theory and simulation of shock waves: Entropy production and energy conversion
Hafskjold, Bjørn; Bedeaux, Dick; Kjelstrup, Signe; Wilhelmsen, Øivind (Journal article; Peer reviewed, 2021)We have considered a shock wave as a surface of discontinuity and computed the entropy production using nonequilibrium thermodynamics for surfaces. The results from this method, which we call the “Gibbs excess method” ...