Begell House
Journal of Porous Media
Journal of Porous Media
1091-028X
19
11
2016
EXPERIMENTAL AND COMPUTATIONAL CALCULATION OF LONGITUDINAL SPECIFIC AIR PERMEABILITY IN POPULUS DELTOIDES AND POPULUS EUROAMERICANA WOOD
Specific air permeability was measured in the juvenile and mature sections of two poplar species at three different vacuum pressures using an apparatus with 0.001 s precision; the values were then compared with those obtained through computational calculations based on the number and diameter of vessels in each section. Cylindrical longitudinal specimens were prepared with 17.5 mm diameter, at two lengths of 50 and 100 mm. Results showed that vacuum pressure did not affect the experimental permeability values, although at lower pressures the permeability values tended to slightly decrease. Computational calculation of permeability showed the same permeability values for the two lengths of specimens in both species, while the values obtained from experimental measurement were significantly different due to the settlement of extractives in vessel elements. Permeability values obtained by computational calculations showed compatibility with vessel lumen area and diameter properties; however, no compatibility was found with vessel frequency. Significant correlation was found between the computational and experimental permeability values only when extractive content was low, and when the number and diameter of vessel elements were within a suitable range for computational modeling. It was therefore concluded that further studies should be carried out on a variety of different wood species to establish a final and authentic model for prediction of specific permeability based on the porous structure and vessel properties.
Hamid Reza
Taghiyari
Wood Science and Technology Department, Faculty of Civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
Alireza
Rahbari
The Australian National University
Sajad
Homayoonfar
Department of Mechanical Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
Javad
Kadkhodapour
Department of Mechanical Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
931-940
NUMERICAL STUDY OF POROUS MEDIA TURBULENT COMBUSTION IN A RECUPERATIVE REACTOR
This paper presents two-dimensional simulations of turbulent porous media combustion of a methane−air mixture in a recuperative reactor. Transport equations were written in their time- and volume-averaged form, and a statistical turbulence model k−ε was applied to simulate turbulence generation due to the porous matrix. ANSYS FLUENT was used to simulate the prototype reactor, and user−defined−function (UDF) interfaces for extra terms involving turbulence were incorporated into the solver interface. The study includes the production of thermal NOx modeled by the extended Zeldovich mechanism with postprocessing computation. Different values of operational variables for superficial velocity and equivalence ratio that enable stable combustion within the sistem were sought. For gas mixtures, increasing the fuel gas inlet velocity is accompanied by higher peak temperatures and combustion front displacement toward the reactor outlet. The NOx formation rate is favored with increasing temperature level inside the reactor but is only significant when the temperature exceeds 1800 K. Heat recovery through the system heat bridge raises the temperature of the incoming gas mixture, allowing one to extend the lower limit of flammability for a given set of operational variables, superficial velocity, and equivalence ratio.
Pablo
Donoso-Garcia
Department of Chemical Engineering, Universidad de Santiago de Chile, B. O'Higgins 3363, Chile
Luis
Henriquez-Vargas
Department of Chemical Engineering, Universidad de Santiago de Chile, 3363 B. O'Higgins, Santiago, Chile
941-953
ANALYSIS OF TIME-DEPENDENT BEHAVIOR OF COUPLED FLOW AND DEFORMATION DUE TO A POINT SINK WITHIN A FINITE RECTANGULAR FLUID-SATURATED POROELASTIC MEDIUM
The time-dependent hydromechanical behavior of a finite two-dimensional (2D) fluid-saturated poroelastic medium induced by sine /constant-rate point sink is investigated analytically in detail. In the case of sine point sink, the displacements and pore pressure exhibit approximate cyclicity with time, which is in tune with the periodicity of sine point sink. In the case of a constant-rate point sink, the analytical solution is compared with an uncoupled exact solution available in the literature. Their similarity in form validates the accuracy of the presented analytical solution in some sense. Then the time-dependent behavior in this case is analyzed, and the effects of concerned parameters on the poroelastic behavior are studied. The results reveal that pore pressure tends to be linear with respect to time rather than presenting a typical dissipation effect. This phenomenon is mainly determined by impervious boundary conditions. Unlike the behavior of a pore pressure field, the displacements increase rapidly with time at the early stage and eventually reach a steady state as time is large enough. This remarkable feature is the consequence of combined actions of the pore pressure dissipation effect and the dragging effect. Parametric studies show that the location change of the point sink has a significant influence on the distributions of displacement field and pore pressure field, while the magnitude of pumping rate or scaled sink strength only affects the size of pore pressure or the displacements. Additionally, the geometrical size of the studied region plays a dominant role in determining the consolidation time. The results in this paper are of great help to provide in-depth insights into the time-dependent behavior of fluid-solid interaction due to fluid withdrawal within finite 2D porous materials.
Peichao
Li
Shanghai University of Engineering Science
Keyong
Wang
School of Mechanical Engineering, Shanghai University of Engineering Science, Shanghai
201620, P. R. China
Detang
Lu
Department of Modern Mechanics, University of Science and Technology of China, Hefei 230027, P. R. China
955-973
APPLICATION OF A NEW ANALYTICAL METHOD FOR THE RICHARDS' EQUATION, BASED ON THE BROOKS AND COREY MODEL
This paper is concerned with the traveling wave solutions and analytical treatment of the infiltration equation. Based on the new technique, namely, the tan (Φ(ξ) / 2)-expansion method, the solution procedure of the nonlinear infiltration equation is investigated. We obtained the exact solutions for the aforementioned nonlinear infiltration equation. These solutions contain four types of hyperbolic function, a trigonometric function, and exponential and rational solutions. Recently this method was developed for searching exact traveling wave solutions of nonlinear partial differential equations. It is shown that this method, with the help of symbolic computation, provides a straightforward and powerful mathematical tool for solving nonlinear partial differential equations.
Jalil
Manafian
Department of Applied Mathematics, Faculty of Mathematics Science, University of Tabriz, Tabriz, Iran
Mehrdad
Lakestani
Department of Applied Mathematics, Faculty of Mathematics Science, University of Tabriz, Tabriz, Iran
Ahmet
Bekir
Eskisehir Osmangazi University, Department of Mathematics − Computer, 26480, Eskisehir- Turkey
975-991
APPLICATIONS OF POROUS MATERIALS AND NANOPARTICLES IN IMPROVING SOLAR DESALINATION SYSTEMS
The effect of varying the absorber materials on the productivity of distillate was investigated experimentally. The first absorber material was porous media; light-colored and black-colored sponges. The second absorber material tested was manganese dioxide powder. The porous materials were also combined with the MnO2 nanoparticles to investigate their effects on the distillate output. The baseline model was used for comparison when using different absorber materials. The results of this investigation showed that the addition of porous medium to the absorber increased the distillate output by 38% and 192% for the light and dark sponges, respectively, compared with the baseline model. The addition of MnO2 increased the absorption of solar energy and consequently increased the mass flow rate of distilled water. The highest mass flow rate output was attributed to MnO2 and the dark sponge at 3.648 kg/m2/day, followed by a dark sponge 3.064 kg/m2/day.
Ehab
Bani-Hani
Mechanical Engineering Department, Australian College of Kuwait, Safat 13015, Kuwait
Christopher
Borgford
Mechanical Engineering Department, Australian College of Kuwait, Safat 13015, Kuwait
Khalil
Khanafer
Mechanical Engineering Department, Australian College of Kuwait, Kuwait
993-999
SEQUENTIALLY COUPLED MODEL FOR MULTIPHASE FLOW, MEAN STRESS, AND REACTIVE SOLUTE TRANSPORT WITH KINETIC CHEMICAL REACTIONS: APPLICATIONS IN CO2 GEOLOGICAL SEQUESTRATION
The significance of thermal-hydrological-mechanical-chemical (THMC) interactions is well identified during the operation of CO2 geosequestration. Geomechanical and geochemical effects may significantly affect aqueous phase composition, porosity, and permeability of the formation, which in turn influence flow and transport. A mean stress formulation is proposed to represent the geomechanical effects such as stresses, displacements, and rock deformation. The geochemistry is described mathematically under equilibrium and kinetic conditions. Based on these theories, a sequentially coupled computational framework is proposed and used to simulate reactive transport of water, supercritical CO2, and species in subsurface formation with geomechanics. A practical reactive transport example with complex chemical compositions is presented to analyze the THMC processes quantitatively on the coupled effects of geochemical reaction and geomechanics for CO2 geosequestration. The results indicate that the THMC coupling effects are not obvious during CO2 sequestration. The geomechanical effect dominates the early period of CO2 injection, and the geochemical reaction dominates the long-term fate of CO2. The efficacy of mineral trapping of supercritical CO2 with respect to 30% plagioclase feldspar minerals in a sandstone reservoir increases to 65% after 10,000 years.
Ronglei
Zhang
Energy Modeling Group, Petroleum Engineering Department, Colorado School of Mines, Golden, Colorado 80401, USA
Yu-Shu
Wu
Energy Modeling Group, Petroleum Engineering Department, Colorado School of Mines, Golden, Colorado 80401, USA
1001-1021