Continuum Modeling of Strongly-coupled Diffusion, Stress, and Solute Concentration

2012 ◽  
Keyword(s):  
Solute Concentration ◽  
Continuum Modeling ◽  
Strongly Coupled ◽  
Coupled Diffusion ◽  
Diffusion Stress

Continuum and atomistic models of strongly coupled diffusion, stress, and solute concentration

2011 ◽  
Vol 196 (1) ◽  
pp. 361-370 ◽  
Author(s):  
Hamed Haftbaradaran ◽  
Jun Song ◽  
W.A. Curtin ◽  
Huajian Gao
Keyword(s):  
Solute Concentration ◽  
Strongly Coupled ◽  
Coupled Diffusion ◽  
Atomistic Models ◽  
Diffusion Stress

scholarly journals A Coupled Thermodynamic Model for Transport Properties of Thin Films during Physical Aging

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 387 ◽  
Author(s):  
Hongjiu Hu ◽  
Xiaoming Fan ◽  
Yaolong He
Keyword(s):  
Thin Films ◽  
Transport Properties ◽  
Free Volume ◽  
Physical Aging ◽  
Field Equations ◽  
Lattice Contraction ◽  
Strongly Coupled ◽  
Coupled Diffusion ◽  
Coupled Field Equations ◽  
Short Time

A coupled diffusion model based on continuum thermodynamics is developed to quantitatively describe the transport properties of glassy thin films during physical aging. The coupled field equations are then embodied and applied to simulate the transport behaviors of O2 and CO2 within aging polymeric membranes to validate the model and demonstrate the coupling phenomenon, respectively. It is found that due to the introduction of the concentration gradient, the proposed direct calculating method on permeability can produce relatively better consistency with the experimental results for various film thicknesses. In addition, by assuming that the free volume induced by lattice contraction is renewed upon CO2 exposure, the experimental permeability of O2 within Matrimid® thin film after short-time exposure to CO2 is well reproduced in this work. Remarkably, with the help of the validated straightforward permeability calculation method and free volume recovery mechanism, the permeability behavior of CO2 is also well elucidated, with the results implying that the transport process of CO2 and the variation of free volume are strongly coupled.

A model of hindered solute transport in a poroelastic shale

1994 ◽  
Vol 445 (1925) ◽  
pp. 679-692 ◽  
Keyword(s):  
Pore Pressure ◽  
Direct Effect ◽  
Swelling Pressure ◽  
Solute Concentration ◽  
Solute Diffusion ◽  
Permeable Membrane ◽  
Coupled Diffusion ◽  
Final Steady State ◽  
Thermodynamic Pressure ◽  
Osmotic Pressure Difference

Theories for the transport of solvent and solute through an imperfect semi-permeable membrane are used as the basis for a model of transport through shale. The flow of solute is reduced, relative to that of solvent, by a transmission coefficient λ ≼ 1. In this model, it is assumed that the chemical composition of the pore fluid has no direct effect upon the swelling of the shale, other than via the thermodynamic pressure p . Invasion is governed by a pair of coupled diffusion equations. There is an initial, rapid diffusion of pressure, leading to a swelling pressure (1-λ) RT ∆ x / V w , where RT ∆ x / V w is the van’t Hoff osmotic pressure difference due to a change in solute mole fraction ∆ x . A subsequent slow diffu­sion process, dominated by diffusion of the solute, then occurs. A change in solute concentration has been assumed to have no direct effect upon the rock, and ultimately has no effect upon the pore pressure and stress. Nevertheless, imperfect exclusion of solute can lead to transient changes in pore pressure which might destabilize the shale before the final steady state is achieved. This is demonstrated by a poroelastic analysis of pressure and solute diffusion into rock surrounding a wellbore.

A finite element simulation on fully coupled diffusion, stress and chemical reaction

2022 ◽  
pp. 104217
Author(s):  
Hui-Jie Cheng ◽  
Xian-Cheng Zhang ◽  
Yun-Fei Jia ◽  
Fuqian Yang ◽  
Shan-Tung Tu
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Chemical Reaction ◽  
Coupled Diffusion ◽  
Element Simulation ◽  
Diffusion Stress ◽  
Fully Coupled

Mixed isogeometric analysis of strongly coupled diffusion in porous materials

2018 ◽  
Vol 114 (1) ◽  
pp. 28-46 ◽  
Author(s):  
B. Dortdivanlioglu ◽  
A. Krischok ◽  
L. Beirão da Veiga ◽  
C. Linder
Keyword(s):  
Porous Materials ◽  
Isogeometric Analysis ◽  
Strongly Coupled ◽  
Coupled Diffusion

scholarly journals Strongly Coupled Diffusion Fluxes

Nature ◽  
1972 ◽  
Vol 235 (5334) ◽  
pp. 130-130
Keyword(s):  
Strongly Coupled ◽  
Coupled Diffusion
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