scholarly journals Non-equilibrium Computer Simulations of Coupling Effects under Thermal Gradients

2017 ◽  
Vol 23 (3) ◽  
Author(s):  
Fernando Bresme
Keyword(s):  
Computer Simulations ◽  
Thermal Gradients ◽  
Coupling Effects ◽  
Non Equilibrium

A Theoretical Study of the Temperature Gradient Effect on the Soret Coefficient in n-Pentane/n-Decane Mixtures Using Non-Equilibrium Molecular Dynamics

2020 ◽  
Vol 45 (4) ◽  
pp. 319-332
Author(s):  
Xiaoyu Chen ◽  
Ruquan Liang ◽  
Yong Wang ◽  
Ziqi Xia ◽  
Lichun Wu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Temperature Gradient ◽  
Thermal Gradient ◽  
Linear Response ◽  
Theoretical Study ◽  
Soret Coefficient ◽  
Thermal Gradients ◽  
Gradient Effect ◽  
Non Equilibrium Molecular Dynamics ◽  
Non Equilibrium

AbstractThe effect of the temperature gradient on the Soret coefficient in n-pentane/n-decane (n-C5/n-C10) mixtures was investigated using non-equilibrium molecular dynamics (NEMD) with the heat exchange (eHEX) algorithm. n-Pentane/n-decane mixtures with three different compositions (0.25, 0.5, and 0.75 mole fractions, respectively) and the TraPPE-UA force field were used in computing the Soret coefficient ({S_{T}}) at 300 K and 1 atm. Added/removed heat quantities (ΔQ) of 0.002, 0.004, 0.006, 0.008, and 0.01 kcal/mol were employed in eHEX processes in order to study the effect of different thermal gradients on the Soret coefficient. Moreover, a phenomenological description was applied to discuss the mechanism of this effect. Present results show that the Soret coefficient values firstly fluctuate violently and then become increasingly stable with increasing ΔQ (especially in the mixture with a mole fraction of 0.75), which means that ΔQ has a smaller effect on the Soret coefficient when the temperature gradient is higher than a certain thermal gradient. Thus, a high temperature gradient is recommended for calculating the Soret coefficient under the conditions that a linear response and constant phase are ensured in the system. In addition, the simulated Soret coefficient obtained at the highest ΔQ within three different compositions is in great agreement with experimental data.

Umbrella sampling in non-equilibrium computer simulations

2005 ◽  
Vol 169 (1-3) ◽  
pp. 64-68 ◽  
Author(s):  
Ronald Blaak ◽  
Hartmut Löwen
Keyword(s):  
Computer Simulations ◽  
Umbrella Sampling ◽  
Non Equilibrium

D-gun Sprayed Fe-Al Single Particle Solidification

2014 ◽  
Vol 59 (1) ◽  
pp. 211-220 ◽  
Author(s):  
W. Wołczyński ◽  
C. Senderowski ◽  
J. Morgiel ◽  
G. Garzeł
Keyword(s):  
Steel Substrate ◽  
Equilibrium Phase ◽  
Thermal Gradients ◽  
Proposed Model ◽  
Solidification Processes ◽  
Solid Liquid Interface ◽  
Solidification Mechanism ◽  
Solid Liquid ◽  
Al Coating ◽  
Non Equilibrium

Abstract Some Fe-Al particles less than 50 μm in diameter were deposited onto the steel substrate by means of the D-gun spraying. A solidification mechanism of an individual particle is described. The particle subjected to the description contained nominally 63 at.% Al. The description was preceded by the TEM / SAED analysis of both the Fe-Al coating and Ni-20Cr interlayer. The whole number of the analyzed particles was partially melted during the deposition. The solidification products like: amorphous phase sub-layer, oscillatory sub-layer which contains two types lamellae distributed alternately and typically non-equilibrium phase sub-layer were revealed. In the micro scale, solidification was considered as a process which occurred in two directions: towards the substrate and towards the non-melted particle part. Both solidification processes underwent the positive thermal gradients. The boron addition was localized within the eutectic precipitates pushed and then rejected by the solid/liquid interface of the solidifying non-equilibrium phase. The proposed model is a general one and therefore can be applied to other systems ;description.

Nonequilibrium depletion interactions in active microrheology

Soft Matter ◽  
2017 ◽  
Vol 13 (48) ◽  
pp. 9093-9102 ◽  
Author(s):  
R. Wulfert ◽  
U. Seifert ◽  
T. Speck
Keyword(s):  
Computer Simulations ◽  
Colloidal Particle ◽  
Superposition Approximation ◽  
Non Equilibrium ◽  
Depletion Forces ◽  
Depletion Interactions

We calculate non-equilibrium depletion forces between a driven and a passive colloidal particle within a dynamical superposition approximation and in computer simulations.

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