Begell House Inc.
Journal of Porous Media
JPM
1091-028X
23
4
2020
DYNAMIC PROBLEM OF SATURATED SOIL UNDER THE FRACTIONAL ORDER THEORY OF THERMOELASTICITY
311-325
10.1615/JPorMedia.2020020592
Chunbao
Xiong
School of Civil Engineering, Tianjin University, Tianjin 300072, People's Republic of China
Ying
Guo
School of Civil Engineering, Henan University of Science and Technology, Luoyang 471023,
Henan, China; Henan International Joint Laboratory of Particulate and Multiphase Flow Science, Luoyang 471023, Henan, China; School of Mechanical and Electrical Engineering, Henan University of Science and Technology,
Luoyang 471023, Henan, China
Yu
Diao
School of Civil Engineering, Tianjin University, Tianjin 300072, P.R. China
fractional order generalized thermoelasticity
thermo-hydro-mechanical
poroelastic
normal mode analysis
relaxation time
In this article, we consider the thermo-hydro-mechanical (THM) problem of a poroelastic half-space soil medium subjected to time harmonic loads consisting of both normal and thermal loads in the context of the fractional order theory of thermoelasticity with one relaxation time. The foundation material is a uniform, fully saturated, poroelastic half-space medium. Normal mode analysis was used to obtain expressions for the nondimensional vertical displacement, excess pore water pressure, vertical stress, and temperature distribution on the poroelastic half-space medium, and the expressions were represented graphically. The effects of the fractional order parameters and time parameters on all physical variables were analyzed in the numerical results.
COMBINED INFLUENCE OF BROWNIAN MOTION AND THERMOPHORESIS ON MAXWELL THREE-DIMENSIONAL NANOFLUID FLOW OVER STRETCHING SHEET WITH CHEMICAL REACTION AND THERMAL RADIATION
327-340
10.1615/JPorMedia.2020027982
P.
Sreedevi
Department of Mathmetatics, Rajeev Gandhi Memorial College of Engineering & Technology,
Nandyal-518501, AP, India
Patakota Sudarsana
Reddy
Department of Mathmetatics, Rajeev Gandhi Memorial College of Engineering & Technology,
Nandyal-518501, AP, India
thermal radiation
Maxwell nanofluid
thermophoresis
Buongiorno's nanofluid model
finite-element method
chemical reaction
The current investigation discovers the magnetohydrodynamic (MHD) heat and mass transfer three-dimensional boundary layer flow of Maxwell nanofluid through a stretching sheet. The mathematical formulation of flow, heat, and mass transfer is presented through the boundary layer equations under convective boundary conditions. The resulting nonlinear boundary layer partial differential equations are converted into the system of nonlinear ordinary differential equations through the suitable similarity transformation technique. The subsequent nonlinear equations are solved using a finite-element method to scrutinize the sway of pertinent constraints on hydrodynamic, temperature, and concentration sketches in the boundary layer regime. The values of local skin-friction coefficient, rates of temperature and rates of concentration are also investigated numerically. The results indicate that with intensifying values of Deborah number the velocity profiles deteriorate, whereas the temperature profiles increase.
THERMAL DISPERSION AND BUONGIORNO'S NANOFLUID MODEL EFFECTS ON NATURAL CONVECTION IN AN INCLINED RECTANGULAR ENCLOSURE PARTIALLY FILLED WITH HEAT GENERATING POROUS MEDIUM
341-361
10.1615/JPorMedia.2020026476
Z. Z.
Rashed
Mathematics Department, Faculty of Science and Arts, Jouf University, Qurayyat, Saudi
Arabia
Sameh Elsayed
Ahmed
Department of Mathematics, Faculty of Science, King Khalid University, Abha 62529, Saudi
Arabia; Department of Mathematics, Faculty of Science, South Valley University, Qena 83523, Egypt
Z. A. S.
Raizah
Department of Mathematics, Faculty of Science, King Khalid University, Abha 62529, Saudi
Arabia
fluid/porous layer
inclined enclosures
thermal dispersion
inertia terms
finite volume method
In this paper, heat transfer enhancement using nanofluids in inclined rectangular enclosures consisting of fluid layer and heat generating porous layer in the presence of thermal dispersion effects is investigated. Buongiorno's model is applied for the nanofluid, while the Brinkman-extended Darcy model with the Forchheimer inertia terms is applied for the porous layer. Two systems of partial differential equations are introduced for the two layers, and they are merged in one dimensionless system using a binary parameter. The finite volume method is applied to solve this system, and comparisons with previously published results are conducted. Wide ranges of the key parameters are considered, and the obtained results are introduced in terms streamlines, isotherms, nanoparticle volume fraction, and local Nusselt number at the wall next to the fluid layer and the wall next to the porous layer. It is found that the increase in the Rayleigh number enhances the buoyancy force in the porous layer leading to support the nanofluid flow inside this layer. Although the effect of Darcy number is more effective in the porous layer, it leads to an enhancement in the local Nusselt number on the left and right walls with the same rate.
NEUTRON DIFFUSION ANALYSIS OF A FUEL PEBBLE WITH VOLUME AVERAGING METHOD
363-381
10.1615/JPorMedia.2020027522
Carlos Gilberto
Aguilar Madera
Universidad Autónoma de Nuevo León, Facultad de Ciencias de la Tierra, C.P. 67700, Linares,
México
Gilberto
Espinosa-Paredes
Área de Ingeniería en Recursos Energéticos, Universidad Autónoma Metropolitana-Iztapalapa,
Av. San Rafael Atlixco No. 186, Col. Vicentina, C.P. 09340, Cd. de México, México
volume averaging method
neutron diffusion equation
nuclear reactor
closure relationships
upscaled equation
numerical computation
The nuclear reactor is a highly heterogeneous system where the nuclear and heat transfer processes take place at multiple scales. With the volume-averaged method, a nuclear reactor can be upscaled. However, with this methodology one integro-differential mathematical model is obtained containing more unknown variables, i.e., dependent variables with respect to the nonaveraged model. Thus, in order to obtain one upscaled and closed neutron diffusion equation, we present the closure problems that were numerically solved to compute the effective coefficients. These closure problems are defined as integro-differential boundary-value problems at microscale. In order to demonstrate the applicability of the theory, we solved the closure problems and computed effective coefficients for a Generation IV nuclear reactor containing pebble bed nuclear fuel. The results obtained with the volume-averaged model agree well with those from the classic diffusion theory and Boltzmann's equation.
TRANSPORT OF A HEATED HYDROPHOBIC SPHERICAL PARTICLE THROUGH POROUS MEDIUM
383-394
10.1615/JPorMedia.2020021179
U. K.
Ghoshal
Department of Mathematics, S P Jain College, Sasaram, Bihar 821115, India
S.
Bhattacharyya
Department of Mathematics, Indian Institute of Technology Kharagpur, Kharagpur 721302,
India
Ali J.
Chamkha
Faculty of Engineering, Kuwait College of Science and Technology, Doha District, Kuwait;
Center of Excellence in Desalination Technology, King Abdulaziz University, P.O. Box 80200,
Jeddah 21589, Saudi Arabia; Mechanical Engineering Department, Prince Sultan Endowment for Energy and
Environment, Prince Mohammad Bin Fahd University, Al-Khobar 31952, Saudi Arabia; RAK Research and Innovation Center, American University of Ras Al Khaimah, P.O. Box
10021, Ras Al Khaimah, United Arab Emirates
mixed convection
slip length
numerical methods
drag factor
Nusselt number
In this paper propulsion of a hydrophobic particle in a gel medium is analyzed numerically. Transport of nanoparticles in gel medium has relevance in the context of controlled drug delivery, colloid separation, and biotechnology. The gel medium is considered to be a homogeneous porous medium, and the hydrodynamics in the gel medium is governed by the Brinkman equation. A Navier-slip boundary condition on the surface of the particle is imposed. We have considered the hydrodynamics of microsized particles by considering the Reynolds number, based on the particle radius and translational velocity, as O(1). Subsequently, we have presented results for mixed convection of the heated hydrophobic particle for a moderate range of Reynolds number. Hydrophobicity of the particle creates a large reduction in drag compared to a hydrophilic particle. The variation of the drag factor, which measures the ratio of drag of a hydrophobic particle suspended in gel and clear fluid, with the gel permeability is found to be similar for any choice of the particle slip length. The flow separation from the surface of the hydrophobic particle delays with respect to Reynolds number. Heat transfer is relatively little influenced by the surface hydrophobicity of the particle.
THE EFFECT OF PHASE-LAGS AND GRAVITY ON MICROPOLAR THERMOELASTIC MEDIUM WITH TEMPERATURE DEPENDENT PROPERTIES
395-412
10.1615/JPorMedia.2020020275
Samia M.
Said
Department of Mathematics, Faculty of Science, Zagazig University, P.O. Box 44519, Zagazig,
Egypt; Department of Mathematics, Faculty of Science and Arts, Al-Mithnab, Qassim
University, P.O. Box 931, Buridah 51931, Al-Mithnab, Kingdom of Saudi Arabia
Green-Naghdi theory
gravitational field
micropolar
three-phase-lag model
temperature dependent properties
The present paper is concerned with wave propagation in a micropolar thermoelastic solid with temperature dependent properties under the effect of a gravitational field. The formulation of the problem was applied in the context of the three-phase-lag model and Green-Naghdi theory without dissipation. The medium is a homogeneous isotropic thermoelastic in the half-space. The exact expressions of the considered variables were obtained using normal mode analysis. The results from the two theories were compared in the absence and presence of the gravitational field as well as temperature dependent properties. A comparison was also made for the two theories without micropolar constants.