eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2018-07-01
4
3
133
139
10.22055/jacm.2017.22206.1128
13099
مقاله پژوهشی
Transient Natural Convection in an Enclosure with Variable Thermal Expansion Coefficient and Nanofluid Properties
Esmaeil Ghahremani
eghahremani86@gmail.com
1
Department of Energy Engineering and Physics, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Islamic Republic of Iran
Transient natural convection is numerically investigated in an enclosure using variable thermal conductivity, viscosity, and the thermal expansion coefficient of Al2O3-water nanofluid. The study has been conducted for a wide range of Rayleigh numbers (103≤ Ra ≤ 106), concentrations of nanoparticles (0% ≤ ϕ ≤ 7%), the enclosure aspect ratio (AR =1), and temperature differences between the cold and hot walls (∆T= 30). Transient parameters such as development time and time-average Nusselt number along the cold wall are also presented as a non-dimensional form. Increasing the Rayleigh number shortens the non-dimensional time of the initializing stage. By increasing the volume fraction of nanoparticles, the flow development time shows different behaviors for various Rayleigh numbers. The non-dimensional development time decreases by enhancing the concentration of nanoparticles.
http://jacm.scu.ac.ir/article_13099_bc7fbf2899e409686ed46e9a9988a56c.pdf
Nanofluid
Natural convection
variable property
transient natural convection
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2018-07-01
4
3
140
146
10.22055/jacm.2017.22996.1146
13152
مقاله پژوهشی
Buckling Analysis of Embedded Nanosize FG Beams Based on a Refined Hyperbolic Shear Deformation Theory
Aicha Bessaim
aicha.bessaim@gmail.com
1
Mohammed Sid Ahmed Houari
houarimsa@yahoo.fr
2
Bousahla Abdelmoumen Anis
bousahla.anis@gmail.com
3
Abdelhakim Kaci
abdelhakim.kaci@gmail.com
4
Abdelouahed Tounsi
tou_abdel@yahoo.com
5
El Abbes Adda Bedia
adda.bedia@gmail.com
6
Département de génie civil, Faculté des Sciences et Technologie, Université Mustapha Stambouli de Mascara, 29000, Algérie | Laboratoire des Structures et Matériaux Avancés dans le Génie Civil et Travaux Publics, Université de Sidi Bel Abbes, 22000, Algérie | Laboratoire des Matériaux et Hydrologie, Université de Sidi Bel Abbes, 22000, Algérie
Département de génie civil, Faculté des Sciences et Technologie, Université Mustapha Stambouli de Mascara, 29000, Algérie | Laboratoire des Structures et Matériaux Avancés dans le Génie Civil et Travaux Publics, Université de Sidi Bel Abbes, 22000, Algérie | Laboratoire des Matériaux et Hydrologie, Université de Sidi Bel Abbes, 22000, Algérie
Laboratoire des Matériaux et Hydrologie, Université de Sidi Bel Abbes, 22000, Algérie | Laboratoire de Modélisation et Simulation Multi-échelle, Université de Sidi Bel Abbés, Algeria | Centre Universitaire de Relizane, Algérie
Laboratoire des Matériaux et Hydrologie, Université de Sidi Bel Abbes, 22000, Algérie
Laboratoire des Structures et Matériaux Avancés dans le Génie Civil et Travaux Publics, Université de Sidi Bel Abbes, 22000, Algérie | Laboratoire des Matériaux et Hydrologie, Université de Sidi Bel Abbes, 22000, Algérie
Laboratoire de Modelisation et Simulation Multi-echelle, Universite de Sidi Bel Abbes, Algeria
In this study, the mechanical buckling response of refined hyperbolic shear deformable (FG) functionally graded nanobeams embedded in an elastic foundation is investigated based on the refined hyperbolic shear deformation theory. Material properties of the FG nanobeam change continuously in the thickness direction based on the power-law model. To capture small size effects, Eringen’s nonlocal elasticity theory is adopted. Employing Hamilton’s principle, the nonlocal governing equations of FG nanobeams embedded in the elastic foundation are obtained. To predict the buckling behavior of embedded FG nanobeams, the Navier-type analytical solution is applied to solve the governing equations. Numerical results demonstrate the influences of various parameters such as elastic foundation, power-law index, nonlocal parameter, and slenderness ratio on the critical buckling loads of size dependent FG nanobeams.
http://jacm.scu.ac.ir/article_13152_ea7f900222f2f8ab4a01ec11850c1f02.pdf
FG nanobeam
Elastic foundation
buckling
nonlocal elasticity theory
Shear deformation beam theory
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2018-07-01
4
3
147
160
10.22055/jacm.2017.22661.1138
13235
مقاله پژوهشی
Differential Quadrature Method for Dynamic Buckling of Graphene Sheet Coupled by a Viscoelastic Medium Using Neperian Frequency Based on Nonlocal Elasticity Theory
Mohammad Malikan
mohammad.malikan@yahoo.com
1
Mohammad Naser Sadraee Far
sadrayifar_m@yahoo.com
2
Department of Mechanical engineering, faculty of engineering, Islamic Azad University, Mashhad branch, Iran
Department of mechanical engineering, Islamic Azad university, Mashhad
In the present study, the dynamic buckling of the graphene sheet coupled by a viscoelastic matrix was studied. In light of the simplicity of Eringen's non-local continuum theory to considering the nanoscale influences, this theory was employed. Equations of motion and boundary conditions were obtained using Mindlin plate theory by taking nonlinear strains of von Kármán and Hamilton's principle into account. On the other hand, a viscoelastic matrix was modeled as a three-parameter foundation. Furthermore, the differential quadrature method was applied by which the critical load was obtained. Finally, since there was no research available for the dynamic buckling of a nanoplate, the static buckling was taken into consideration to compare the results and explain some significant and novel findings. One of these results showed that for greater values of the nanoscale parameter, the small scale had further influences on the dynamic buckling.
http://jacm.scu.ac.ir/article_13235_97bcdc2fe5d861b8a98c5ad3f8e064b9.pdf
Dynamic buckling
Graphene sheet
Viscoelastic matrix
differential quadrature method
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2018-07-01
4
3
161
166
10.22055/jacm.2017.22854.1141
13202
مقاله پژوهشی
Moving Mesh Non-standard Finite Difference Method for Non-linear Heat Transfer in a Thin Finite Rod
Morteza Bisheh-Niasar
mbisheh@kashanu.ac.ir
1
Maryam Arab Ameri
arabameri@math.usb.ac.ir
2
Department of Applied Mathematics, Faculty of Mathematical Science, University of
Kashan, Kashan, Iran.
Department of Mathematics, University of Sistan and Baluchestan, Zahedan, Iran.
In this paper, a moving mesh technique and a non-standard finite difference method are combined, and a moving mesh non-standard finite difference (MMNSFD) method is developed to solve an initial boundary value problem involving a quartic nonlinearity that arises in heat transfer with thermal radiation. In this method, the moving spatial grid is obtained by a simple geometric adaptive algorithm to preserve stability. Moreover, it uses variable time steps to protect the positivity condition of the solution. The results of this computational technique are compared with the corresponding uniform mesh non-standard finite difference scheme. The simulations show that the presented method is efficient and applicable, and approximates the solutions well, while because of producing unreal solution, the corresponding uniform mesh non-standard finite difference fails.
http://jacm.scu.ac.ir/article_13202_1b9af05f7f7f9589e48852976ff2e4be.pdf
Non-standard finite difference
positivity
moving mesh
heat conduction equation
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2018-07-01
4
3
167
174
10.22055/jacm.2017.22933.1144
13194
مقاله پژوهشی
Inherent Irreversibility of Exothermic Chemical Reactive Third-Grade Poiseuille Flow of a Variable Viscosity with Convective Cooling
S.O. Salawu
kunlesalawu2@gmail.com
1
S.I. Oke
segunoke2016@gmail.com
2
Department of Mathematics, Landmark University, Omu-aran, Nigeria
Department of Mathematical Sciences, University of Zululand, Zululand, South Africa
In this study, the analysis of inherent irreversibility of chemical reactive third-grade poiseuille flow of a variable viscosity with convective cooling is investigated. The dissipative heat in a reactive exothermic chemical moves over liquid in an irreversible way and the entropy is produced unceasingly in the system within the fixed walls. The heat convective exchange with the surrounding temperature at the plate surface follows Newton’s law of cooling. The solutions of the dimensionless nonlinear equations are obtained using weighted residual method (WRM). The solutions are used to obtain the Bejan number and the entropy generation rate for the system. The influence of some pertinent parameters on the entropy generation and the Bejan number are illustrated graphically and discussed with respect to the parameters.
http://jacm.scu.ac.ir/article_13194_1b328c31e4aa09a8339ba5500e57793f.pdf
Exothermic reaction
third-grade fluid
Poiseuille flow
variable viscosity
Convective cooling
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2018-07-01
4
3
175
186
10.22055/jacm.2017.22987.1145
13243
مقاله پژوهشی
Exact Radial Free Vibration Frequencies of Power-Law Graded Spheres
Vebil Yıldırım
vebil@cu.edu.tr
1
Cukurova University, Department of Mechanical Engineering, Turkey
This study concentrates on the free pure radial vibrations of hollow spheres made of hypothetically functionally simple power rule graded materials having identical inhomogeneity indexes for both Young’s modulus and the density in an analytical manner. After offering the exact elements of the free vibration coefficient matrices for free-free, free-fixed, and fixed-fixed restraints, a parametric study is fulfilled to study the effects of both the aspect ratio and the inhomogeneity parameters on the natural frequencies. The outcomes are presented in both graphical and tabular forms. It was seen that the fundamental frequency is mostly affected by the inhomogeneity parameters rather than the higher ones. However, the natural frequencies except the fundamental ones are dramatically affected by the thickness of the sphere. It is also revealed that there is a linear relationship between the fundamental frequency and others in higher modes of the same sphere under all boundary conditions.
http://jacm.scu.ac.ir/article_13243_4eaf2ad4b85da776b36411af6335d886.pdf
free vibration
Functionally graded
Exact solution
Hollow sphere
Thick-walled
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2018-07-01
4
3
187
201
10.22055/jacm.2017.23057.1148
13234
مقاله پژوهشی
Bending of Shear Deformable Plates Resting on Winkler Foundations According to Trigonometric Plate Theory
Atteshamuddin Sayyad
attu_sayyad@yahoo.co.in
1
Yuwaraj M. Ghugal
ghugal@rediffmail.com
2
SRES College of Engineering, Kopargaon, Maharashtra, India.
Head of Department of Applied Mechanics, Govt. College of EngineeringKarad, Shivaji University, Maharashtra-415124, India
A trigonometric plate theory is assessed for the static bending analysis of plates resting on Winkler elastic foundation. The theory considers the effects of transverse shear and normal strains. The theory accounts for realistic variation of the transverse shear stress through the thickness and satisfies the traction free conditions at the top and bottom surfaces of the plate without using shear correction factors. The governing equations of equilibrium and the associated boundary conditions of the theory are obtained using the principle of virtual work. A closed-form solution is obtained using double trigonometric series. The numerical results are obtained for flexure of simply supported plates subjected to various static loadings. The displacements and stresses are obtained for three different values of foundation modulus. The numerical results are also generated using higher order shear deformation theory of Reddy, first order shear deformation theory of Mindlin, and classical plate theory for the comparison of the present results.
http://jacm.scu.ac.ir/article_13234_41ee272c21e0931940c8393ec05e7f83.pdf
Shear deformation
normal strain
Shear stress
shear correction factor
Winkler elastic foundation
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2018-07-01
4
3
202
215
10.22055/jacm.2017.23096.1149
13203
مقاله پژوهشی
Semi-Analytical Solution for Vibration of Nonlocal Piezoelectric Kirchhoff Plates Resting on Viscoelastic Foundation
D.P. Zhang
d.p.zhang@hotmail.com
1
Yongjun Lei
leiyj108@nudt.edu.cn
2
Z.B. Shen
z.b.shen@hotmail.com
3
College of Aerospace Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073, China
College of Aerospace Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073, China
College of Aerospace Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073, China
Semi-analytical solutions for vibration analysis of nonlocal piezoelectric Kirchhoff plates resting on viscoelastic foundation with arbitrary boundary conditions are derived by developing Galerkin strip distributed transfer function method. Based on the nonlocal elasticity theory for piezoelectric materials and Hamilton's principle, the governing equations of motion and boundary conditions are first obtained, where external electric voltage, viscoelastic foundation, piezoelectric effect, and nonlocal effect are considered simultaneously. Subsequently, Galerkin strip distributed transfer function method is developed to solve the governing equations for the semi-analytical solutions of natural frequencies. Numerical results from the model are also presented to show the effects of nonlocal parameter, external electric voltages, boundary conditions, viscoelastic foundation, and geometric dimensions on vibration responses of the plate. The results demonstrate the efficiency of the proposed methods for vibration analysis of nonlocal piezoelectric Kirchhoff plates resting on viscoelastic foundation.
http://jacm.scu.ac.ir/article_13203_8c61226444364818bc945b3647976948.pdf
Nonlocal piezoelectric plates
Vibration characteristics
viscoelastic foundation
Galerkin strip distributed transfer function method
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2018-07-01
4
3
216
230
10.22055/jacm.2017.23188.1150
13293
مقاله پژوهشی
The Complementary Functions Method (CFM) Solution to the Elastic Analysis of Polar Orthotropic Rotating Discs
Vebil Yıldırım
vebil@cu.edu.tr
1
Department of Mechanical Engineering, Çukurova University, Adana, 01330, Turkey
This study primarily deals with introducing an efficient numerical technique called the Complementary Functions Method (CFM) for the solutions of the initial value problem for the linear elastic analysis of anisotropic rotating uniform discs. To bring the performance of the method to light, first, closed form formulas are derived for such discs. The governing equation of the problem at stake is solved analytically with the help of the Euler-Cauchy technique under three types of boundary conditions namely free-free, fixed-free, and fixed-guided constraints. Secondly, the CFM is applied to the same problem. It was found that both numerical and analytical results coincide with each other up to a desired numerical accuracy. Third, after verifying the results with the literature, a parametric study with CFM on the elastic behavior of discs made up of five different materials which physically exist is performed. And finally, by using hypothetically chosen anisotropy degrees from 0.3 through 5, the effects of the anisotropy on the elastic response of such structures are investigated analytically. Useful graphs are provided for readers.
http://jacm.scu.ac.ir/article_13293_64e5af46bf182153111bbf596f22db7c.pdf
Initial value problem (IVP)
Exact elasticity solution
Polar orthotropic
Rotating disc
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2018-07-01
4
3
231
244
10.22055/jacm.2017.23557.1163
13292
مقاله پژوهشی
Verification and Validation of Common Derivative Terms Approximation in Meshfree Numerical Scheme
Zhibo Ma
mazhibo@iapcm.ac.cn
1
Yazhou Zhao
asiabuaasa@163.com
2
Institute of Applied Physics and Computational Mathematics, China
Division of Water Resources and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
In order to improve the approximation of spatial derivatives without meshes, a set of meshfree numerical schemes for derivative terms is developed, which is compatible with the coordinates of Cartesian, cylindrical, and spherical. Based on the comparisons between numerical and theoretical solutions, errors and convergences are assessed by a posteriori method, which shows that the approximations for functions and derivatives are of the second accuracy order, and the scale of the support domain has some influences on numerical errors but not on accuracy orders. With a discrete scale h=0.01, the relative errors of the numerical simulation for the selected functions and their derivatives are within 0.65%.
http://jacm.scu.ac.ir/article_13292_2fbc5a7086ed163a0cc15b7e895c10da.pdf
Meshfree method
Smoothed particle hydrodynamics
Physics evoked cloud method
Approximation of spatial derivative
Verification and validation