scholarly journals Three-Scale Multiphysics Modeling of Transport Phenomena within Cortical Bone

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
T. Lemaire ◽  
J. Kaiser ◽  
S. Naili ◽  
V. Sansalone
Keyword(s):  
Cortical Bone ◽  
Transport Phenomena ◽  
Outer Wall ◽  
Scale Model ◽  
Coupled Transport ◽  
Onsager Reciprocity ◽  
Coupled Equations ◽  
Reciprocity Relations ◽  
Fluid Compartments ◽  
Treated Site

Bone tissue can adapt its properties and geometry to its physical environment. This ability is a key point in the osteointegration of bone implants since it controls the tissue remodeling in the vicinity of the treated site. Since interstitial fluid and ionic transport taking place in the fluid compartments of bone plays a major role in the mechanotransduction of bone remodeling, this theoretical study presents a three-scale model of the multiphysical transport phenomena taking place within the vasculature porosity and the lacunocanalicular network of cortical bone. These two porosity levels exchange mass and ions through the permeable outer wall of the Haversian-Volkmann canals. Thus, coupled equations of electrochemohydraulic transport are derived from the nanoscale of the canaliculi toward the cortical tissue, considering the intermediate scale of the intraosteonal tissue. In particular, the Onsager reciprocity relations that govern the coupled transport are checked.

Application of Meshless Pore-Level Model to Pyrolysis and Synthesis of Nuclear Fuels

2007 ◽  
Author(s):  
Xiaolin Wang ◽  
Hui Zhang ◽  
Lili Zheng
Keyword(s):  
Material Processing ◽  
Transport Phenomena ◽  
Nuclear Material ◽  
Processing Technique ◽  
System Level ◽  
Scale Model ◽  
Nuclear Fuels ◽  
Particle Hydrodynamics ◽  
Level Model ◽  
Pore Level

Uranium-ceramic nuclear fuels can be fabricated through pyrolysis-based materials processing technique. This technique requires lower energy compared to sintering route. During the fabrication process, the source material changes composition continuously and chemical reactions and transport phenomena vary accordingly. Therefore, to obtain such nuclear fuel materials with high uniformity of microstructure/species without crack, transport phenomena in the material processing needs to be better understood. A system-scale model has been developed to account for the pyrolysis-based uranium-ceramic nuclear material processing in our prior work. In this study, a pore-scale numerical model based on Smoothed Particle Hydrodynamics (SPH) will be described for modeling the synthesis of SiC matrix and U3O8. The system-level model provides thermal boundary conditions to the pore-level model. The microstructure and compositions of the produced composites will be studied. Since the control of process temperature plays an important role in the material quality, the effects of heating rate and U3O8 particle size and volume on species uniformity and microstructure are investigated.

scholarly journals Electro-Osmotic Behavior of Polymeric Cation-Exchange Membranes in Ethanol-Water Solutions

Entropy ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 692
Author(s):  
V. María Barragán ◽  
Juan P. G. Villaluenga ◽  
Víctor Morales-Villarejo ◽  
M. Amparo Izquierdo-Gil
Keyword(s):  
Cation Exchange ◽  
Streaming Potential ◽  
Membrane System ◽  
Electrolyte Solutions ◽  
Joule Effect ◽  
Potential Coefficient ◽  
Water Solutions ◽  
Onsager Reciprocity ◽  
Ethanol Content ◽  
Reciprocity Relations

The aim of this work is to apply linear non-equilibrium thermodynamics to study the electrokinetic properties of three cation-exchange membranes of different structures in ethanol-water electrolyte solutions. To this end, liquid uptake and electro-osmotic permeability were estimated with potassium chloride ethanol-water solutions with different ethanol proportions as solvent. Current–voltage curves were also measured for each membrane system to estimate the energy dissipation due to the Joule effect. Considering the Onsager reciprocity relations, the streaming potential coefficient was discussed in terms of ethanol content of the solutions and the membrane structure. The results showed that more porous heterogeneous membrane presented lower values of liquid uptake and streaming potential coefficient with increasing ethanol content. Denser homogeneous membrane showed higher values for both, solvent uptake and streaming coefficient for intermediate content of ethanol.

Investigation of Wedge Probe Wall Proximity Effects: Part 2—Numerical and Analytical Modeling

1997 ◽  
Vol 119 (3) ◽  
pp. 605-611 ◽  
Author(s):  
P. D. Smout ◽  
P. C. Ivey
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Outer Wall ◽  
Aerodynamic Characteristics ◽  
Proximity Effects ◽  
Wake Flow ◽  
Scale Model ◽  
Flow Structures ◽  
Flow Features ◽  
Wall Proximity

An experimental study of wedge probe wall proximity effects is described in Part 1 of this paper. Actual size and large-scale model probes were tested to understand the mechanisms responsible for this effect, by which free-stream pressure near the outer wall of a turbomachine may be overindicated by up to 20 percent dynamic head. CFD calculations of the flow over two-dimensional wedge shapes and a three-dimensional wedge probe were made in support of the experiments, and are reported in this paper. Key flow structures in the probe wake were identified that control the pressures indicated by the probe in a given environment. It is shown that probe aerodynamic characteristics will change if the wake flow structures are modified, for example by traversing close to the wall, or by calibrating the probe in an open jet rather than in a closed section wind tunnel. A simple analytical model of the probe local flows was derived from the CFD results. It is shown by comparison with experiment that this model captures the dominant flow features.

Investigation of Wedge Probe Wall Proximity Effects: Part 2 — Numerical and Analytical Modelling

1996 ◽  
Author(s):  
Peter D. Smout ◽  
Paul C. Ivey
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Outer Wall ◽  
Aerodynamic Characteristics ◽  
Proximity Effects ◽  
Wake Flow ◽  
Scale Model ◽  
Flow Structures ◽  
Flow Features ◽  
Wall Proximity

An experimental study of wedge probe wall proximity effects is described in Part 1 of this paper. Actual size and large scale model probes were tested to understand the mechanisms responsible for this effect, by which free stream pressure near the outer wall of a turbomachine may be over indicated by upto 20% dynamic head. CFD calculations of the flow over two-dimensional wedge shapes and a three-dimensional wedge probe were made in support of the experiments, and are reported in this paper. Key flow structures in the probe wake were identified which control the pressures indicated by the probe in a given environment. It is shown that probe aerodynamic characteristics will change if the wake flow structures are modified, for example by traversing close to the wall, or by calibrating the probe in an open jet rather than in a closed section wind tunnel. A simple analytical model of the probe local flows was derived from the CFD results. It is shown by comparison with experiment that this model captures the dominant flow features.

scholarly journals Specimen-specific multi-scale model for the anisotropic elastic constants of human cortical bone

2009 ◽  
Vol 42 (13) ◽  
pp. 2061-2067 ◽  
Author(s):  
Justin M. Deuerling ◽  
Weimin Yue ◽  
Alejandro A. Espinoza Orías ◽  
Ryan K. Roeder
Keyword(s):  
Cortical Bone ◽  
Elastic Constants ◽  
Scale Model ◽  
Multi Scale ◽  
Human Cortical Bone ◽  
Anisotropic Elastic

On the Inclusion of Some Biological Impacts and Influences in Coupled Transport Phenomena in Unsaturated Soil

2010 ◽  
Vol 29 (2) ◽  
pp. 181-191
Author(s):  
Hywel Rhys Thomas ◽  
Suresh Channarayapatna Seetharam ◽  
Philip James Vardon
Keyword(s):  
Unsaturated Soil ◽  
Transport Phenomena ◽  
Coupled Transport ◽  
Biological Impacts
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