Frequency dependence of acoustic response due to randomness and uncertainties in physical properties of porous media

1998 ◽  
Vol 103 (5) ◽  
pp. 2934-2935
Author(s):  
Yongke Mu ◽  
Mohsen Badiey ◽  
Alexander H.‐D. Cheng
Keyword(s):  
Porous Media ◽  
Physical Properties ◽  
Frequency Dependence ◽  
Acoustic Response

Numerical Model of Complex Porous Media

2002 ◽  
Author(s):  
Andre´ Chambarel ◽  
Herve´ Bolvin
Keyword(s):  
Porous Media ◽  
Numerical Model ◽  
Physical Properties ◽  
Space Distribution ◽  
Partial Differential ◽  
Differential Problem ◽  
Classical Models ◽  
Element Approach ◽  
Statistical Approaches ◽  
Percolation Phenomenon

In complex porous media we often notice a percolation phenomenon [KIR 71] [GRI 89]. Usually these media present discontinuous characteristics and a random space distribution [LET 00] [BIR 95]. There results that the classical models based on the resolution of a partial differential problem become inefficient because we have non-derivable function [MAU 01]. Statistical approaches based on the resolution of partial differential problems pose notably the questions concerning the continuity of the functions representing the physical properties of the medium. In this work we propose to study a numerical model of porous media based on a mixture of 2 components in a percolation context. In practice, the main difficulty is based on the complex physical properties. We present also a model of homogenization. Our numerical model is based on the Finite Element approach.

Moisture Effective Diffusivity in Porous Media with Different Physical Properties

2006 ◽  
Vol 258-260 ◽  
pp. 207-212
Author(s):  
Miranda M.N.N. ◽  
M.A. Silva
Keyword(s):  
Porous Media ◽  
Diffusion Coefficient ◽  
Moisture Content ◽  
Mass Transport ◽  
Physical Properties ◽  
Pore Size ◽  
Structural Properties ◽  
Effective Diffusivity ◽  
Nay Zeolite ◽  
Moisture Effective Diffusivity

In the drying of porous media, the mass transport occurs in the pores as well as on the surface of the solid. The mechanisms involved can take place simultaneously, influenced by the predominant one and can change depending on the moisture content. In this work, the moisture effective diffusivity was estimated in solids with distinct structural properties in order to verify the predominant mechanisms according to the moisture content, analyzing the influence of the physical properties. The materials studied were NaY Zeolite, Kaolin, Silica and Alumina. The results of diffusion coefficient present a minimum at low moisture content that can be related to pore size.

Frequency dependence of sound propagation in superfluid-filled porous media

1994 ◽  
Vol 50 (21) ◽  
pp. 15896-15908 ◽  
Author(s):  
Kevin Warner ◽  
J. R. Beamish
Keyword(s):  
Porous Media ◽  
Frequency Dependence ◽  
Sound Propagation

scholarly journals Dryout and Replenishment of Bottom-Heated Saturated Porous Media with an Overlying Plain Water Layer

2018 ◽  
Vol 8 (12) ◽  
pp. 2607
Author(s):  
Montserrat Carbonell ◽  
Luis Virto ◽  
Pedro Gamez-Montero
Keyword(s):  
Porous Media ◽  
Physical Properties ◽  
Thermal State ◽  
Water Layer ◽  
Coarse Sand ◽  
Solid Matrix ◽  
Plain Water ◽  
Liquid Phases ◽  
State Evolution ◽  
The Stability

The aim of this paper is to elucidate the influence of the physical properties of both phases—solid matrix and saturating liquid—of bottom-heated porous media with an overlying plain water layer. The dryout, the stability of the system’s water layer-vapor region, and the thermal state evolution are studied. The porous media under study are a bronze powder saturated by water, and a solution of surfactant and coarse sand saturated by the same liquids. From the experimental data obtained, a theoretical approach is carried out to describe the dryout and rewetting process. The influence of the nature and physical properties of the solid and liquid phases is also analyzed, with special attention to the addition of surfactant in the saturating liquid.

scholarly journals Analysis of CT-Measured Pore Characteristics of Porous Media Relative to Physical Properties

2016 ◽  
Vol 95 ◽  
pp. 442-449 ◽  
Author(s):  
P. Adhikari ◽  
S.H. Anderson ◽  
R.P. Udawatta ◽  
S. Kumar
Keyword(s):  
Porous Media ◽  
Physical Properties ◽  
Pore Characteristics

A Pore-Scale Reactive Transport Model Approach for Investigating the Effect of Soil Physical Properties on Biogeochemical Processes

2020 ◽  
Author(s):  
Amir Golparvar ◽  
Matthias Kästner ◽  
Martin Thullner
Keyword(s):  
Porous Media ◽  
Physical Properties ◽  
Vadose Zone ◽  
Reactive Transport ◽  
Soil Physical Properties ◽  
Transport Processes ◽  
Biogeochemical Processes ◽  
Pore Scale ◽  
Model Approach

<p>The vadose zone hosts a wide range of various microorganisms which provide different soil ecosystem services from nutrient cycling to biodegradation of harmful chemical substances. The efficiency of such in-situ biodegradation is influenced by different biotic and abiotic factors ranging from physical properties of the soil to the redox conditions controlled by the activity of the involved chemical compounds. One important feature of the soil system is the dynamical and simultaneous interplay of these factors, boosting or deteriorating the residing microbial community’s abundance and/or activity and hence shaping biodegradation of vadose zone contaminants. Physical properties of porous media – e.g. the pore geometry, pore size distribution, connectivity as well as the water content – play a major role in enhancing or restricting the bioavailable concentration of contaminants and other reaction partners. Pore-scale phenomena have been shown to be considerably affecting the macro-scale processes, therefore a quantitative bottom-top approach of these mechanisms in situ is adamant. Hence it is of paramount importance to understand the effect of soil physical properties on microbial activity and biodegradation of carbon compounds in soil.</p><p>Pore scale reactive transport processes have a complex, nonlinear dependency on the aforementioned factors, which severely challenges the experimental and/or numerical investigation of biodegradation at in in-situ conditions. However, the recent technological advances, specifically the imaging techniques, have made it easier to study biological and microbial evolution in porous media, but there is still a need for putting all these information together. For this purpose, numerical methods would offer the possibility of simulating a variable/controllable water saturation conditions and considering water/air dynamics and advective and diffusive micro-scale transport of all components in both, air and water phase, in porous medium structures directly obtained from CT scanned samples. Up to now, such pore-sale model approaches considering also the fate of biogeochemically reactive compounds are scarce. In this work we propose a novel reactive transport modelling technique combining the pore-scale numerical characterization of water flow and solute transport in unsaturated porous media and of biogeochemical process. For a variably saturated porous system, the presented model approach is solving the Navier Stokes equation and scalar transport equations for any arbitrary geometry and is simulating the dynamics of biogeochemical processes with any degree of complexity. Simulations are compared to experimental data to assess the effect of soil physical properties on the transport and degradation of contaminants in soil.</p>

scholarly journals Laboratory Measurement and Interpretation of the Changes of Physical Properties after Heat Treatment in Tight Porous Media

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Yili Kang ◽  
Mingjun Chen ◽  
Lijun You ◽  
Xiangchen Li
Keyword(s):  
Heat Treatment ◽  
Porous Media ◽  
Physical Properties ◽  
Gas Production ◽  
Treatment Temperature ◽  
High Temperature Treatment ◽  
Tight Gas ◽  
Tight Sandstone ◽  
Structure Generation ◽  
Tight Porous Media

Prevention of water blocking and optimization of multiscale flow channels will increase gas production of tight reservoirs. Physical properties of samples from representative tight gas reservoirs were measured before and after high temperature treatment. Results show that, with the increase of treatment temperature, mass decreases, acoustic transit time increases, and permeability and porosity increase. Permeability begins to increase dramatically if treatment temperature exceeds the threshold value of thermal fracturing, which is 600~700°C, 500~600°C, 300~500°C, and 300~400°C for shale, mudstone, tight sandstone, and tight carbonate rock, respectively. Comprehensive analyses indicate that the mechanisms of heat treatment on tight porous media include evaporation and dehydration of water, change of mineral structure, generation of microfracture, and network connectivity. Meanwhile, field implementation is reviewed and prospected. Interpretations indicate that, according to the characteristics of multiscale mass transfer in tight gas formation, combining heat treatment with conventional stimulation methods can achieve the best stimulation result.

Acoustic response characteristics of unsaturated porous media

2010 ◽  
Vol 53 (8) ◽  
pp. 1388-1396 ◽  
Author(s):  
HaiBo Zhao ◽  
XiuMing Wang ◽  
ShuMin Chen ◽  
LaiLin Li
Keyword(s):  
Porous Media ◽  
Unsaturated Porous Media ◽  
Acoustic Response ◽  
Response Characteristics

scholarly journals Frequency dependence simulation of electromagnetic characteristics for saturated porous media

2016 ◽  
pp. 425-436
Author(s):  
Д.А. Лисицын ◽  
Л.Е. Довгилович
Keyword(s):  
Porous Media ◽  
Frequency Dependence ◽  
Density Functional ◽  
Water Saturation ◽  
Numerical Models ◽  
Density Functional Method ◽  
Relative Dielectric Permittivity ◽  
Effective Parameters ◽  
Component Distribution ◽  
Electromagnetic Characteristics

Представлен метод, позволяющий проводить численное моделирование эффективных спектральных электромагнитных характеристик многокомпонентно насыщенных пористых сред. Приведены результаты применения этого метода к численным моделям пористых сред, распределение компонентов флюида в которых определяется путем прямого гидродинамического моделирования методом функционала плотности. Обсуждаются результаты моделирования частотной зависимости эффективной электрической проводимости и эффективной диэлектрической проницаемости модели пористой среды при различных величинах водонасыщенности модели и при различных условиях смачиваемости материала породы. Проведено сравнение результатов для случаев без учета и с учетом частотной зависимости параметров одного из компонентов флюида. Выполнен анализ влияния соотношения между характеристиками компонентов системы на результаты моделирования. A method to perform numerical simulations of effective spectral electromagnetic characteristics for porous media saturated with multicomponent fluid is proposed. This method is applied to numerical models of porous media whose fluid component distribution is determined by the direct hydrodynamic simulation using the density functional method. The numerical results obtained for the effective electrical conductivity and relative dielectric permittivity of porous media with various water saturation values and rock wettability are discussed. The results obtained with consideration of the frequency dependence of one of the fluid components and without considering such a dependence are compared. The effect of the relation between the electrical characteristics of components in the model on the effective parameters is analyzed.

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