RECENT ADVANCES ON FRACTAL MODELING OF PERMEABILITY FOR FIBROUS POROUS MEDIA

Fractals ◽  
2015 ◽  
Vol 23 (01) ◽  
pp. 1540006 ◽  
Author(s):  
JIANCHAO CAI ◽  
LIANG LUO ◽  
RAN YE ◽  
XIANGFENG ZENG ◽  
XIANGYUN HU
Keyword(s):  
Porous Media ◽  
Pore Structure ◽  
Fractal Geometry ◽  
Influence Factor ◽  
Fractal Model ◽  
Fibrous Materials ◽  
Permeability Model ◽  
Fractal Modeling ◽  
Fibrous Porous Media ◽  
Future Work

Permeability is an important hydraulic parameter for characterizing heat and mass transfer properties of fibrous porous media. However, it is difficult to be quantitatively predicted due to the complex and irregular pore structure of fibrous porous media. Fractal geometry has been verified to be an effective method for determining the permeability of fibrous porous media. In this study, recent works on the permeability of fibrous porous media by means of fractal geometry are reviewed, the advances for each presented fractal model are analyzed and summarized, parameter equations used in available fractal permeability models are also briefly compared and reviewed. Future work for more generalized permeability model of fibrous porous media need to conducted by considering the special characters of fibrous materials, uniform pore structure parameter model and the influence factor of capillary pressure, electrokinetic phenomena, etc.

Fractal Model for Thermal Conductivity of Wetting, Fibrous Porous Media

2012 ◽  
Vol 496 ◽  
pp. 12-16
Author(s):  
Fang Long Zhu ◽  
De Hong Xia ◽  
Yu Zhou
Keyword(s):  
Thermal Conductivity ◽  
Porous Media ◽  
Fractal Dimension ◽  
Effective Thermal Conductivity ◽  
Fractal Model ◽  
Self Similarity ◽  
Conductivity Model ◽  
Electrical Analogy ◽  
Fibrous Porous Media ◽  
Thermal Conductivity Model

The current paper deals with the fractal effective thermal conductivity model for fibrous porous media containing unsaturated water moisture. The model is based on the thermal-electrical analogy and statistical self-similarity of porous media. The fractal effective thermal conductivity model can be expressed as a function of the pore structure (fractal dimension) and architectural parameters of porous media. It is expected that the model will be helpful in the evaluation of thermal comfort for textiles in the whole range of porosity.

A fractal model for capillary flow through a single tortuous capillary with roughened surfaces in fibrous porous media

Fractals ◽  
2020 ◽  
Author(s):  
Boqi Xiao ◽  
Qiwen Huang ◽  
Yan Wang ◽  
Hanxin Chen ◽  
Xubing Chen ◽  
...  
Keyword(s):  
Porous Media ◽  
Capillary Flow ◽  
Fractal Model ◽  
Fibrous Porous Media ◽  
Flow Through

scholarly journals Fractal Modeling of Pore Structure and Ionic Diffusivity for Cement Paste

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yun Gao ◽  
Jin-yang Jiang ◽  
Kai Wu
Keyword(s):  
Pore Structure ◽  
Cement Paste ◽  
Mercury Intrusion Porosimetry ◽  
Fractal Model ◽  
Homogenization Method ◽  
Solid Mass ◽  
Fractal Modeling ◽  
Mass Fractal ◽  
Chloride Migration ◽  
Ionic Diffusivity

Pore structure in cement based composites is of paramount importance to ionic diffusivity. In this paper, pore structure in cement paste is modeled by means of the recently proposed solid mass fractal model. Moreover, an enhanced Maxwell homogenization method that incorporates the solid mass fractal model is proposed to determine the associated ionic diffusivity. Experiments are performed to validate the modeling, that is, mercury intrusion porosimetry and rapid chloride migration. Results indicate that modeling agrees well with those obtained from experiments.

A FRACTAL MODEL FOR KOZENY–CARMAN CONSTANT AND DIMENSIONLESS PERMEABILITY OF FIBROUS POROUS MEDIA WITH ROUGHENED SURFACES

Fractals ◽  
2019 ◽  
Vol 27 (07) ◽  
pp. 1950116 ◽  
Author(s):  
BOQI XIAO ◽  
YIDAN ZHANG ◽  
YAN WANG ◽  
GUOPING JIANG ◽  
MINGCHAO LIANG ◽  
...  
Keyword(s):  
Porous Media ◽  
Fractal Dimension ◽  
Fluid Transport ◽  
Fractal Theory ◽  
Fractal Model ◽  
Physical Mechanisms ◽  
Relative Roughness ◽  
Fibrous Porous Media ◽  
Effect Of Surface ◽  
Good Agreement

In this paper, fluid transport through fibrous porous media is studied by the fractal theory with a focus on the effect of surface roughness of capillaries. A fractal model for Kozeny–Carman (KC) constant and dimensionless permeability of fibrous porous media with roughened surfaces is derived. The determined KC constant and dimensionless permeability of fibrous porous media with roughened surfaces are in good agreement with available experimental data and existing models reported in the literature. It is found that the KC constant of fibrous porous media with roughened surfaces increases with the increase of relative roughness, porosity, area fractal dimension of pore and tortuosity fractal dimension, respectively. Besides, it is seen that the dimensionless permeability of fibrous porous media with roughened surfaces decreases with increasing relative roughness and tortuosity fractal dimension. However, it is observed that the dimensionless permeability of fibrous porous media with roughened surfaces increases with porosity. With the proposed fractal model, the physical mechanisms of fluids transport through fibrous porous media are better elucidated.

GAS–WATER RELATIVE PERMEABILITIES FRACTAL MODEL IN DUAL-WETTABILITY MULTISCALE SHALE POROUS MEDIA DURING INJECTED WATER SPONTANEOUS IMBIBITION AND FLOW BACK PROCESS

Fractals ◽  
2020 ◽  
Vol 28 (07) ◽  
pp. 2050103
Author(s):  
WENHUI SONG ◽  
JUN YAO ◽  
YANG LI ◽  
HAI SUN ◽  
DONGYING WANG ◽  
...  
Keyword(s):  
Porous Media ◽  
Pore Structure ◽  
Gas Phase ◽  
Gas Flow ◽  
Fractal Dimensions ◽  
Fractal Model ◽  
Spontaneous Imbibition ◽  
Relative Permeabilities ◽  
Free Gas ◽  
Study Results

The multiphase flow behavior in shale porous media is known to be affected by multiscale pore size, dual surface wettability, and nanoscale transport mechanisms. However, it has not been fully understood so far. In this study, fractal model of gas–water relative permeabilities (RP) in dual-wettability shale porous media for both injected water spontaneous imbibition and the flow back process are proposed using fractal geometry. The shale pore structure is described as tortuous with different pore sizes and morphologies including slit pore, equilateral triangle, circular pore and square pore. The proportion of each pore morphology can be obtained from SEM/FIB-SEM pore structure characterization results. Injected water spontaneous imbibition after hydraulic fracturing is modeled as the capillary force dominated process and injected water flow back is modeled as a non-wetting gas phase drainage process in inorganic matter. The organic pores are deemed to be not accessible by injected water. The boundary slip of water and free gas flow in the inorganic matrix are considered while both free gas flow and adsorbed gas flow are modeled in organic matter. The proposed gas–water RP fractal model is verified via comparisons with the available experimental data and is discussed in detail. Study results reveal that gas phase RP increases with increasing pore fractal dimensions and tortuosity fractal dimensions, whereas it decreases with increasing Total Organic Carbon (TOC) volumes. Water phase RP decreases with increasing of pore fractal dimensions and tortuosity fractal dimensions, whereas it increases with increasing TOC volumes.

A difference-fractal model for the permeability of fibrous porous media

2010 ◽  
Vol 374 (10) ◽  
pp. 1201-1204 ◽  
Author(s):  
Dahua Shou ◽  
Jintu Fan ◽  
Feng Ding
Keyword(s):  
Porous Media ◽  
Fractal Model ◽  
Fibrous Porous Media
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