Abo Bibliothek: Guest

ANISOTROPIC DIFFUSION IN FIBROUS POROUS MEDIA

Volumen 13, Ausgabe 1, 2010, pp. 1-11
DOI: 10.1615/JPorMedia.v13.i1.10
Get accessDownload

ABSTRAKT

Some porous media possess fibrous structures. Examples include the geologically deformed porous rocks, white matter in human brain tissue, and fiber-reinforced composite materials. These anisotropic porous media show strong diffusive anisotropy. This study focused on a system consisting of randomly placed parallel rods as a model of fibrous porous media, and describes the analysis of three-dimensional diffusive anisotropy through the lattice random walk computer simulations. The rods were completely impermeable, and nonsorbing random walkers migrate in the percolated pore space between the parallel rods. Direction-dependent self-diffusivity was calculated by taking the time derivative of the mean square displacement of the walkers, and its three-dimensional shape was expressed graphically as a shell-like object by polar representation. Systematic simulations for varied rod packing densities revealed that the shell-like object was no longer convex ellipsoidal, but was constricted in the direction normal to the rod axis when the maximum-to-minimum diffusivity ratio of the diffusion ellipsoids exceeded 1.5 (i.e., when the rod volume fraction exceeded 34 vol %). An analytical solution of the direction-dependent self-diffusivity with constriction is presented for the lattice walk along a straight pore. The solution suggests that the ellipsoid constriction observed for the randomly placed parallel rods is a remnant of the anisotropic pore structure of the hexagonal closest packing, which is the end member of the rod packing. The onset condition of the constriction of the shape of the direction-dependent self-diffusivity is investigated analytically using a diffusion tensor expression. The analysis reveals that the constriction occurs when the maximum-to-minimum diffusivity ratio exceeds exactly 1.5, which agrees well with the simulation results. The critical value of 1.5 can also be applicable to the geologically deformed natural porous rocks having more complex pore structure compared with the simple rod packing system.

REFERENZIERT VON
  1. Nakashima Yoshito, Nakano Tsukasa, Steady-State Local Diffusive Fluxes in Porous Geo-Materials Obtained by Pore-Scale Simulations, Transport in Porous Media, 93, 3, 2012. Crossref

  2. Zhu Fanglong, Zhou Yu, Feng Qianqian, Xia Dehong, Moisture diffusivity in structure of random fractal fiber bed, Physics Letters A, 377, 37, 2013. Crossref

  3. Javid Khurram, Khan Salah Ud-Din, Khan Shahab Ud-Din, Hassan Mohsan, Khan Abdullah, Alharbi Sulaiman Ali, Mathematical modeling of magneto-peristaltic propulsion of a viscoelastic fluid through a complex wavy non-uniform channel: an application of hall device in bio-engineering domains, The European Physical Journal Plus, 136, 2, 2021. Crossref

Zukünftige Artikel

ON THERMAL CONVECTION IN ROTATING CASSON NANOFLUID PERMEATED WITH SUSPENDED PARTICLES IN A DARCY-BRINKMAN POROUS MEDIUM Pushap Sharma, Deepak Bains, G. C. Rana Effect of Microstructures on Mass Transfer inside a Hierarchically-structured Porous Catalyst Masood Moghaddam, Abbas Abbassi, Jafar Ghazanfarian Insight into the impact of melting heat transfer and MHD on stagnation point flow of tangent hyperbolic fluid over a porous rotating disk Priya Bartwal, Himanshu Upreti, Alok Kumar Pandey Numerical Simulation of 3D Darcy-Forchheimer Hybrid Nanofluid Flow with Heat Source/Sink and Partial Slip Effect across a Spinning Disc Bilal Ali, Sidra Jubair, Md Irfanul Haque Siddiqui Fractal model of solid-liquid two-phase thermal transport characteristics in the rough fracture network shanshan yang, Qiong Sheng, Mingqing Zou, Mengying Wang, Ruike Cui, Shuaiyin Chen, Qian Zheng Application of Artificial Neural Network for Modeling of Motile Microorganism-Enhanced MHD Tangent Hyperbolic Nanofluid across a vertical Slender Stretching Surface Bilal Ali, Shengjun Liu, Hongjuan Liu Estimating the Spreading Rates of Hazardous Materials on Unmodified Cellulose Filter Paper: Implications on Risk Assessment of Transporting Hazardous Materials Heshani Manaweera Wickramage, Pan Lu, Peter Oduor, Jianbang Du ELASTIC INTERACTIONS BETWEEN EQUILIBRIUM PORES/HOLES IN POROUS MEDIA UNDER REMOTE STRESS Kostas Davanas Gravity modulation and its impact on weakly nonlinear bio-thermal convection in a porous layer under rotation: a Ginzburg-Landau model approach Michael Kopp, Vladimir Yanovsky Pore structure and permeability behavior of porous media under in-situ stress and pore pressure: Discrete element method simulation on digital core Jun Yao, Chunqi Wang, Xiaoyu Wang, Zhaoqin Huang, Fugui Liu, Quan Xu, Yongfei Yang Influence of Lorentz forces on forced convection of Nanofluid in a porous lid driven enclosure Yi Man, Mostafa Barzegar Gerdroodbary SUTTERBY NANOFLUID FLOW WITH MICROORGANISMS AROUND A CURVED EXPANDING SURFACE THROUGH A POROUS MEDIUM: THERMAL DIFFUSION AND DIFFUSION THERMO IMPACTS galal Moatimid, Mona Mohamed, Khaled Elagamy CHARACTERISTICS OF FLOW REGIMES IN SPIRAL PACKED BEDS WITH SPHERES Mustafa Yasin Gökaslan, Mustafa Özdemir, Lütfullah Kuddusi Numerical study of the influence of magnetic field and throughflow on the onset of thermo-bio-convection in a Forchheimer‑extended Darcy-Brinkman porous nanofluid layer containing gyrotactic microorganisms Arpan Garg, Y.D. Sharma, Subit K. Jain, Sanjalee Maheshwari A nanofluid couple stress flow due to porous stretching and shrinking sheet with heat transfer A. B. Vishalakshi, U.S. Mahabaleshwar, V. Anitha, Dia Zeidan ROTATING WAVY CYLINDER ON BIOCONVECTION FLOW OF NANOENCAPSULATED PHASE CHANGE MATERIALS IN A FINNED CIRCULAR CYLINDER Noura Alsedais, Sang-Wook Lee, Abdelraheem Aly Porosity Impacts on MHD Casson Fluid past a Shrinking Cylinder with Suction Annuri Shobha, Murugan Mageswari, Aisha M. Alqahtani, Asokan Arulmozhi, Manyala Gangadhar Rao, Sudar Mozhi K, Ilyas Khan CREEPING FLOW OF COUPLE STRESS FLUID OVER A SPHERICAL FIELD ON A SATURATED BIPOROUS MEDIUM Shyamala Sakthivel , Pankaj Shukla, Selvi Ramasamy
Digitales Portal Digitale Bibliothek eBooks Zeitschriften Referenzen und Berichte Forschungssammlungen Preise und Aborichtlinien Begell House Kontakt Language English 中文 Русский Português German French Spain