Begell House Inc.
Journal of Porous Media
JPM
1091-028X
22
7
2019
A CAHN-HILLIARD APPROACH TO THERMODIFFUSION IN POROUS MEDIA
761-785
10.1615/JPorMedia.2019029077
Melania
Carfagna
DISMA "G.L. Lagrange", Politecnico di Torino, C.so Duca degli Abruzzi 24, I-10129, Torino
(TO), Italy
Alfio
Grillo
DISMA "G.L. Lagrange", Politecnico di Torino, C.so Duca degli Abruzzi 24, I-10129, Torino
(TO), Italy
Soret effect
thermodiffusion
mixture theory
Cahn-Hilliard model
We consider a fluid-saturated porous medium exposed to a nonuniform temperature field and describe it as a nonisothermal biphasic mixture comprising a solid and a two-constituent fluid. We model such a system by assuming
that the fluid free energy density depends on the gradient of the solute mass fraction. This constitutive choice induces a coupling between the temperature gradient and the solute diffusive mass flux, which adds itself to the standard Soret effect. We present numerical simulations of a thermogravitational cell to show how the modified constitutive framework, which is mandatory in diffuse-interface problems (e.g., the Cahn-Hilliard model), could lead to some novel interpretations of thermodiffusion and enrich the phenomenological description of the considered benchmarks.
STUDY AND ANALYSIS OF SPATIAL-TIME NONLINEAR FRACTIONAL-ORDER REACTION-ADVECTION-DIFFUSION EQUATION
787-798
10.1615/JPorMedia.2019025907
Anup
Singh
Department of Mathematical Sciences, Indian Institute of Technology (BHU), Varanasi 221005,
India; Department of Mechanical Engineering, IIT Kanpur
Subir
Das
Department of Mathematical Sciences, Indian Institute of Technology (Banaras Hindu
University), Varanasi-221005, India
porous media
groundwater contamination
Legendre collocation method
operational matrix
reaction-advection-diffusion equation
In the present article, the Legendre collocation method is used to solve the fractional-order advection-diffusion equation having a nonlinear type source/sink term with initial and boundary conditions. The solution profiles of the normalized solute concentration for both reaction-advection-diffusion and reaction-diffusion systems are presented through graphs for different particular cases. The salient features of the article are the pictorial presentations of the effects of fractional-order spatial and time derivatives as well as the advection term on the solution profile. An initiative has been taken to compare the numerical solution of our proposed method with the existing analytical solution through error analysis, which is exhibited through figures and a table.
A METHODOLOGY TO CHARACTERIZE FIBER PREFORM PERMEABILITY BY USING KARDAR–PARISI–ZHANG EQUATION
799-811
10.1615/JPorMedia.2019021772
Hatice S.
Sas
Integrated Manufacturing Technologies Research and Application Center, Sabanci University,
Tuzla, 34956, Istanbul, Turkey; Composite Technologies Center of Excellence, Istanbul Technology Development Zone, Sabanci
University-Kordsa Global, Pendik, Istanbul, Turkey
Pavel
Simacek
Department of Mechanical Engineering and Center for Composite Materials, University of
Delaware, Newark, DE 19716
Suresh G.
Advani
Department of Mechanical Engineering and Center for Composite Materials, University of
Delaware, Newark, DE 19716
permeability
Roughness
KPZ equation
Permeability tensor describes the resistance to fluid flow through the fibrous porous media, which may not be spatially
uniform. This nonuniformity in fiber architecture causes variation in the permeability value of the fibrous domain. The time evolution and geometry of the rough interfaces of the fluid flow in fibrous porous medium are analyzed using
the concepts of dynamic scaling and self-affine fractal geometry, and they are shown to belong to the Kardar–Parisi–Zhang (KPZ) universality class. The resulting growth exponent, β is found to match the 1 + 1 KPZ values, and the roughness exponent, α, describes the standard deviation of the variation in fiber preform permeability. Additionally, this characterization is used to develop a tool to quantify the percentage and strength of defects within the fibrous porous media from flow front profile analysis.
NUMERICAL INVESTIGATION OF TEMPERATURE DISTRIBUTION OF PROTON EXCHANGE MEMBRANE FUEL CELLS AT HIGH CURRENT DENSITY
813-829
10.1615/JPorMedia.2019028954
Jun
Shen
School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Lingping
Zeng
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge,
Massachusetts 02139-4307, USA
Zhengkai
Tu
School of Energy and Power Engineering, Huazhong University of Science and Technology,
Wuhan, 430074, China
Zhichun
Liu
School of Energy and Power Engineering, Huazhong University of Science & Tecnology, 1037 Luo Yu Rd. Hongshan District, Wuhan 430074, China
Wei
Liu
School of Energy and Power Engineering, Huazhong University of Science & Tecnology, 1037 Luo Yu Rd. Hongshan District, Wuhan 430074, China
PEM fuel cell
coolant water
temperature distribution
high current density
thermal resistance network
A three-dimensional model with coolant channels was developed to investigate the temperature distribution and performance of proton exchange membrane fuel cells (PEMFCs) under the impacts of different operating conditions, including Reynolds numbers of the coolant water, current densities, and relative humidity levels of reactants. Numerical simulation results revealed that relative humidity had a significant effect either on cell performance or on temperature distribution, and the temperature of the interface between the catalyst and gas diffusion layers in the cathode was the highest of any part in the fuel cell. Limited by the temperature of the coolant, a small rise in the reactant temperature would have little influence on the overall temperature distribution. Lastly, a novel thermal resistance model was proposed to validate the rules governing temperature distribution in fuel cells.
FAST AND INEXPENSIVE 2D-MICROGRAPH BASED METHOD OF PERMEABILITY ESTIMATION THROUGH MICRO-MACRO COUPLING IN POROUS MEDIA
831-849
10.1615/JPorMedia.2019028855
Bamdad
Barari
Laboratory for Flow and Transport Studies in Porous Media, Department of Mechanical
Engineering, University of Wisconsin-Milwaukee, 3200 Cramer St., Milwaukee, WI, 53211
Saman
Beyhaghi
Laboratory for Flow and Transport Studies in Porous Media, Department of Mechanical
Engineering, University of Wisconsin-Milwaukee, 3200 Cramer St., Milwaukee, WI, 53211
Krishna
Pillai
Mechanical Engineering Department, College of Engineering and Applied Science, University of Wisconsin, Room 945, EMS Building, 3200 N. Cramer Street, Milwaukee, WI 53211, USA
porous media
permeability
Whitaker's closure formulation
cellulose nanofiber
polymer
wick
The closure formulation, developed as a part of the derivation of Darcy's law proposed by Whitaker (1998), is used to develop a method based on two-dimensional (2D) micrographs for estimating the full in-plane (2D) permeability tensor of a porous medium without requiring multiple flow simulations in different directions. The governing equations were solved in the pore space of a representative elementary volume (REV) using the finite-element (FE) method via COMSOL Multiphysics software. The permeabilities of two distinct porous media created from cellulose nanofibers (CNF) and sintered polymer beads were then estimated numerically. In order to use real micrographs in such simulations, scanning electron microscopy (SEM) pictures of the CNF and polymer-wick porous media were considered. The mesh-size independence studies were conducted to find the appropriate FE mesh for computations. A falling-head permeameter was used for measuring the experimental permeability in order to test the accuracy of the permeability results obtained by numerical simulation. Unequal diagonal terms of the permeability tensor pointed to the presence of anisotropicity in CNF; such characterization is a benefit of the proposed method. A good agreement between the numerical permeability results and the experimental results confirmed the accuracy of the proposed micro-macro coupling based method in estimating this crucial property using 2D micrographs. This 2D closure-formulation based permeability estimation, which is faster, less expensive, and less troublesome than its three-dimensional (3D) counterpart, has the potential to emerge as a powerful characterization tool in the arsenal of porous-media scientists and researchers.
MULTISCALE AND MULTIPHASE MODELING OF FLOW BEHAVIOR IN DISCRETE FRACTURE NETWORKS FOR TIGHT OIL RESERVOIRS
851-868
10.1615/JPorMedia.2019026028
Lifeng
Liu
PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083,
China
Ning
Li
PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083,
China
Qiquan
Ran
PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083,
China
Yu-Shu
Wu
Energy Modeling Group, Petroleum Engineering Department, Colorado School of Mines, Golden, Colorado 80401, USA
multiscale media
numerical simulation
network fracturing
tight oil reservoirs
Fluid transport in tight reservoirs is obviously a multiscale behavior. The fluid occurrence status and flow mechanisms
are different in different scales of porous media and their characterization and coupled simulation are complex processes.
This study presents a numerical investigation of pressure and flow transient analysis of oil production from a horizontal,
network-fracturing well in tight oil reservoirs. A specialized three-dimensional, three-phase discrete multimedia
numerical simulator which incorporates known non-Darcy behavior in tight oil reservoirs was developed and used
for this purpose. First, we discuss a multipercolation mechanism, multimedia concepts of different scales for handling
microscopic and macroscopic heterogeneity of tight reservoirs after network fracturing. By using the discrete modeling
method, we describe and characterize different scale pores, discrete natural fractures with different scales, and discrete
artificial fractures. The flow simulation in different scale mediums is carried out by the self-recognition method of the
percolation mechanisms. Then sensitivity studies of flow rate are presented with respect to different pore-size distribution
under the same porosity condition. Different sizes of pore distribution patterns have obvious differences in oil
production, which indicates that the characterization of different scale percolation media is crucial to unconventional
tight oil. Specifically, we will analyze a field example from Changqing tight oil to demonstrate the use of results and
methodology of this study.
MORPHOLOGY OF OPEN-CELL FOAMS: A CRITICAL REVIEW AND GEOMETRIC MODELING
869-887
10.1615/JPorMedia.2019028906
Gaetano
Contento
Italian National Agency for New Technologies, Energy and Sustainable Economical Development Brindisi Research Centre (ENEA), 72100, Brindisi, Italy
Marcello
Iasiello
Universita degli Studi di Napoli Federico II, Department of Industrial Engineering, Piazzale Tecchio 80, 80125 Napoli (Italy)
Maria
Oliviero
Consiglio Nazionale delle Ricerche, Istituto per i Polimeri, Compositi e Biomedici, P.le Fermi 1,
80055 Portici, Italy
Nicola
Bianco
Dipartimento di Ingegneria Industriale, Università degli studi di Napoli Federico II, P.le Tecchio 80, 80125, Napoli, Italy
Vincenzo
Naso
Dipartimento di Ingegneria Industriale, Università degli studi di Napoli Federico II, P.le Tecchio 80, 80125, Napoli, Italy
open-cell foams
morphological parameters and correlations
geometric modeling
specific surface area
Transport phenomena through open-cell foams are strongly affected by their complex microstructure. Morphological
parameters, such as the diameter of pores and cells, the strut thickness, and the specific surface area, play key roles. Due to the intricate nature of an open-cell foam, its morphological models are very useful in engineering applications. We first review correlations in the literature of the morphological parameters that affect transport phenomena in foams. Then, with reference to the Kelvin's foam model, we present a unique model for the characterization of morphological parameters of open-cell foams, accounting for different strut shapes. New correlations among morphological parameters are proposed. There is good agreement between the correlations obtained with the proposed model and the experimental results from the literature. The model, accounting for any shape of the struts cross section, predicts values of foam morphological parameters generally closer to those predicted by available models not valid for all strut shapes.