eng
Sharif University of Technology
Scientia Iranica
10263098
23453605
20180801
25
4
2077
2086
10.24200/sci.2017.4505
4505
Analytical solution for coupled nonFickian diffusionthermoelasticity and thermoelastic wave propagation analysis
Seyed Amin Hosseini
amin.hoss@gmail.com
1
Seyed Mahmoud Hosseini
sm_hosseini@um.ac.ir
2
Mohammad Hossein Abolbashari
abolbash@um.ac.ir
3
Mechanical Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, PO Box: 917751111, Mashhad, Iran
Industrial Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, PO Box: 917751111, Mashhad, Iran
The time history analysis and propagation of molar concentration, temperature and displacement waves are studied in details using an analytical method. The method is applied to coupled nonFickian diffusionthermoelasticity analysis of a strip. The governing equations are derived using nonFickian theory of diffusion and classic theories for coupled thermoelasticity. Molar concentration and thermoelastic wave propagations are considered to be of finite speed. The governing equations are first transferred to the frequency domain using Laplace transform technique. The unknown parameters are then obtained in analytical forms proposed by the presented method. By employing the Talbot technique, the unknown parameters are eventually determined in time domain. It can be concluded that the presented analytical method has a high capability for dynamic and transient analysis of coupled diffusionthermoelasticity problems. The wave fronts in displacement, temperature and molar concentration fields can be tracked at various time instants employing the presented analytical method.
http://scientiairanica.sharif.edu/article_4505_a2a13fd85ba5a9e7e8fdf0a175ebcf1e.pdf
NonFickian diffusion
wave propagation
molar concentration
Temperature
analytical method
coupled problems
eng
Sharif University of Technology
Scientia Iranica
10263098
23453605
20180801
25
4
2087
2097
10.24200/sci.2017.4496
4496
Analysis of nonlinear acoustic wave propagation in HIFU treatment using Westervelt equation
Samaneh Haddadi
1
Mohammad Taghi Ahmadian
2
School of Mechanical Engineering, Sharif University of Technology, Azadi Ave., Tehran, Iran
Center of Excellence in Design, Robotics and Automation (CEDRA), School of Mechanical Engineering, Sharif University of Technology, P.O. BOX: 111559567, Tehran, Iran
Currently, the HIFU (High Intensity Focused Ultrasound) therapy method is known as one of the most advanced surgical techniques in tumor ablation therapy. Simulation of the nonlinear acoustic wave and tissue interaction is essential in HIFU planning to improve the usefulness and efficiency of treatment. In this paper, linear, thermoviscous and nonlinear equations are applied using two different media, namely liver and water. Transducer power of 8.3134 Watts with the frequency of 1.1 MHz is considered as the range of study to analyze the wave and tissue interaction. Results indicate that the maximum focal pressure of about 0.54.3 MPa can be achieved for transducer power of 8.3 to 134 W. Simultaneous solving of the acoustic pressure equation and Pennes’s bioheat equation are used to determine the temperature rise at focal point and the ablated area. Finally, the linear and nonlinear simulations are compared, and the turning point of transition from linearity to nonlinearity is determined. The simulated results provide information about the behavior of the focalized ultrasound in interaction with liver tissue. The performance of phased array HIFU transducer can be improved for treatment considering the lesion size, temperature rise in tissue and choosing best range of operational power.
http://scientiairanica.sharif.edu/article_4496_768a03365454f70faac6434084f7d9b9.pdf
HIFU
Nonlinear wave propagation
Pennes’s bioheat equation
KZK equation
and Westervelt equation
eng
Sharif University of Technology
Scientia Iranica
10263098
23453605
20180801
25
4
2098
2110
10.24200/sci.2017.4580
4580
Slip flow of nano fluid over a stretching vertical cylinder in the presence of nonlinear thermal radiation and nonuniform heat source/sink
C. S. Sravanthi
1
Department of Mathematics, The M. S. University of Baroda, Vadodara, Gujarat, India
An analysis is performed to study axisymmetric mixed convective boundary layer flow of a nanofluid over a vertical stretching circular cylinder in the presence of nonlinear radiative heat flux. The effects of nonuniform heat source/sink and slip flow are also taken into consideration. Water as conventional base fluid containing nanoparticles of Copper (Cu) is used. By means of similarity transformations, the governing partial differential equations are reduced into highly nonlinear ordinary differential equations and then solved analytically using Homotopy Analysis Method (HAM). A comparison is made with the available results in the literature and our results are in very good agreement with the known results. A parametric study of the physical parameters is made and results are presented through graphs and tables. The results indicate that, the thermal boundary layer is thicker for nonlinear thermal radiation problem when compared with that of linear thermal radiation. It also found that heat transfer rate at the surface decreases with the increase in both space and time dependent heat source/sink parameters.
http://scientiairanica.sharif.edu/article_4580_6c8dbedce6da0fb0e759b48af9818024.pdf
Nanofluid
stretching vertical cylinder
nonlinear thermal radiation
HAM
eng
Sharif University of Technology
Scientia Iranica
10263098
23453605
20180801
25
4
2111
2129
10.24200/sci.2017.4344
4344
The effect of radial force on pullin instability and frequency of rigid core circular and annular plates subjected to electrostatic field
Masoumeh Khorshidi Paji
1
Morteza Dardel
dardel@nit.ac.ir
2
Mohammad Hadi Pashaei
mpashaei@nit.ac.it
3
Reza Akbari Alashti
4

Department of Mechanical Engineering, Babol Noshirvani University of Technology, P.O. Box 484, Postal Code: 4714871167, Shariati Street, Babol, Mazandaran, Iran


In this work static pullin instability and frequency analysis of circular and annular plates in electrical field was studied. The plate is modeled based on classical plate theory with nonlinear Von Kármán straindisplacement field. The governing equation of motion and boundary conditions were obtained using Hamilton principle. For this purpose potential and kinetic energies and the work done by radial and electrostatic force are obtained. Governing partial differential equations were reduced to ordinary differential equations by Galerkin's method. Then, static pullin instabilities of clamped circular plate and annular plate with clampedclamped and clampedsimply boundary conditions were analyzed by arclength continuation method. The effect of rigid core, radial load, geometric nonlinearity, inner radius and boundary conditions on pullin instability and frequency of the plate has been studied.
http://scientiairanica.sharif.edu/article_4344_8240cab1eb00edbc39c208715efc636a.pdf
Pullin instability
circular and annular plate
rigid core
radial load
arc length continuation
natural frequency
eng
Sharif University of Technology
Scientia Iranica
10263098
23453605
20180801
25
4
2130
2143
10.24200/sci.2017.4347
4347
Numerical solution to NS equations in the case of unsteady axisymmetric stagnationpoint flow on a vertical circular cylinder with mixed convection heat transfer
Reza Bayat
1
Asghar B. Rahimi
rahimiab@um.ac.ir
2
Mechanical Engineering
Faculty of Engineering, Ferdowsi University of Mashhad, P.O. Box No. 917751111, Mashhad, Iran
The unsteady problem of impulsive stagnationpoint flow on a vertical circular cylinder along with mixed convection heat transfer is solved numerically for the first time. This is because of limitations of similarity solution techniques when we encounter various physical conditions such as timedependent states. Initially, the fluid is considered to be at rest and with a uniform temperature . At t=0 this fluid starts flowing toward a vertical cylinder at the strength rate of and the cylinder surface's temperature rises to Tw, simultaneously. The NavierStokes and energy equations in cylindrical coordinate system have been descritized and solved in a 2D domain by using a SIMPLE based algorithm. The solution has been obtained in three cases. Firstly, when cylinder's wall temperature Tw is constant. Secondly, when Tw varies linearly along cylinder's axis. And thirdly, when it has parabolic variations. Considering a sample case of incompressible flow with Re=1 and , the results of Nusselt number, wall shear stress and dimensionless velocity and temperature have been obtained at different states of cylinder's wall temperature and for some selected values of Grashof numbers. An entropy generation analysis for the case of constant wall temperature is performed which is also for the first time in this subject.
http://scientiairanica.sharif.edu/article_4347_868a23e3840fc355e32912940b52bb01.pdf
numerical solution
stagnationpoint flow
vertical circular cylinder
mixed convection
entropy generation
eng
Sharif University of Technology
Scientia Iranica
10263098
23453605
20180801
25
4
2144
2154
10.24200/sci.2017.4341
4341
Closed form solution for direct and inverse kinematics of a USRSRPS 2DOF parallel robot
Javier Sanjuan
1
David Serje
2
Jovanny Pacheco
3
Department of Mechanical Engineering, Universidad del Norte, Km.5 Via Puerto Colombia, Barranquilla, Colombia
Department of Mechanical Engineering, Universidad del Norte, Km.5 Via Puerto Colombia, Barranquilla, Colombia
Department of Mechanical Engineering, Universidad del Norte, Km.5 Via Puerto Colombia, Barranquilla, Colombia
Parallel mechanisms with reduced degree of freedom (DOF) have grown in importancefor industry and researchers as they oer a simpler architecture and lower manufacturing/operating costs with great performance. In this paper, a two degree of freedomparallel robot is proposed and analyzed. The robot with a xed base, a moving platformand three legs achieve translational and rotational motion through actuation on prismaticand revolute joints, and can be applied on pick and place applications, vehicle simulatorsamong others. By making use of homogeneous transformation matrices and Sylvestersdialytic elimination method a closed form solution for direct kinematics is obtained forall possible assembly modes. Inverse kinematics was solved in closed form as well. Thisgreatly decreases computational time and proposed approach is optimal. A case studywas done to validate the solutions found and compared with a CAD model to corroborateresults. Finally, a workspace calculation was made for dierent geometrical parametersof the robot.
http://scientiairanica.sharif.edu/article_4341_c132055d1a35c54eef2e84e83f1776ac.pdf
Parallel kinematics
Forward Kinematics
Pose
Homogeneous Transformation Matrix
Closed form
eng
Sharif University of Technology
Scientia Iranica
10263098
23453605
20180801
25
4
2155
2161
10.24200/sci.2018.20677
20677
Evaluation of microstructural effects on mechanical properties of CT80 grade coiled tubing steel
Hasan Ghiasi
ghiasi@acecr.ac.ir
1
Technology Development Institute, ACECR, Tehran, Iran
The microstructure formation and mechanical properties of coiled tube CT80 grade steel was investigated with different heat treatments. Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) were used to evaluate the microstructure. Acicular ferrite, polygonal and quasipolygonal ferrite, granular bainite, martensite, pearlite, and small MartensiteAustenite (MA) islands with the banding structure were revealed in original and heat treated samples. In order to assess the effect of grain size and microstructure, mechanical properties were evaluated by hardness, charpy impact, tensile, and fatigue life tests. The best mechanical properties by tensile and fatigue test is obtained from the normalized specimen with the grain size of ASTM 13.
http://scientiairanica.sharif.edu/article_20677_964e4417f106ef880697d0a8f349ed82.pdf
CT80 Grade Coiled Tubing Steel
microstructure
Heat treatment
mechanical properties
Fatigue life
eng
Sharif University of Technology
Scientia Iranica
10263098
23453605
20180801
25
4
2162
2174
10.24200/sci.2017.4510
4510
An investigation into the effect of pressure source parameters and water depth on the wake wash wave generated by moving pressure source
Mohammadreza Javanmardi
1
Jonathan Binns
2
Giles Thomas
3
Martin Renilson
4
Sharif University of technology, Tehran, Iran
Australian Maritime College, Launceston, Tasmania, Australia, 7250
University College London, Torrington Place, London WC1E 7JE, UK
University of Tasmania, Launceston, Tasmania, Australia, 7250
In this study the effect of moving pressure source and channel parameters on the generated waves in a channel was numerically investigated. Draught, angle of attack and profile shape were investigated as parameters of pressure source and water depth and blockage factor as channel parameters on wave height. Firstly, the chosen Computational Fluid Dynamics (CFD) approach was validated with the experimental data over a range of speed. Then the CFD study was conducted for further investigations. It was shown that that by enlarging draught, angle of attack and beam of the pressure source, the wave height generated will be increased. Channel study showed that it is possible to increase the wave height generated by shallowing water for a given speed as long as the depth Froude number is subcritical and the wave height generated is independent of water depth for supercritical depth Froude numbers. The blockage factor has more influence at supercritical Froude depth values, while at subcritical Froude values is negligible compare with water depth.
http://scientiairanica.sharif.edu/article_4510_c7491c0a37d69616e97826ef73c876de.pdf
Wake wash
wave propagation
Computational Fluid dynamics
Towing Tank
Pressure Source
eng
Sharif University of Technology
Scientia Iranica
10263098
23453605
20180801
25
4
2175
2185
10.24200/sci.2017.4342
4342
Numerical solutions of Fourier's law involving fractional derivatives with biorder
J.F. GomezAguilar
1
Abdon Atangana
abdonatangana@yahoo.fr
2
R.F. EscobarJimenez
3
CONACyTCentro Nacional de Investigacion y Desarrollo Tecnologico. Tecnologico Nacional de Mexico
Institute for Groundwater Studies, Faculty of Natural and Agricultural Sciences. University of the Free State, Bloemfontein 9300, South Africa.
Centro Nacional de Investigacion y Desarrollo Tecnologico.Tecnologico Nacional de Mexico
In this paper, we present an alternative representation of the fractional spacetimeFourier's law equation using the concept of derivative with two fractionalorders and . The new denitions are based on the concept of power lawand the generalized MittagLeer function, where, the rst fractional orderis included in the power law function and the second fractional order is thegeneralized MittagLeer function. The new approach is capable of consideringmedia with two dierent layers, scales and properties. The generalization ofthis equation exhibit dierent cases of anomalous behavior and NonFourierheat conduction processes. Numerical solutions using an iterative scheme wereobtained.
http://scientiairanica.sharif.edu/article_4342_ccf9a42f1fe362172f8da42497a61daa.pdf
Anomalous difiusion
Fractional heat transfer model
Iterative Method
Biorder fractional derivative
NonFourier heat conduction
eng
Sharif University of Technology
Scientia Iranica
10263098
23453605
20180801
25
4
2186
2197
10.24200/sci.2017.4343
4343
MHD forced convection ow and heat transfer of ferro fluids over a moving at plate with uniform heat flux and secondorder slip effects
N. Ramli
1
S. Ahmad
2
I. Pop
3
School of Mathematical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
School of Mathematical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
Faculty of Mathematics and Computer Science, BabesBolyai University, 400084 ClujNapoca, Romania
In this study, the problem of twodimensional forced convection MHD flow and heat transfer of ferro fluids over a moving at plate with the influence of uniform heat flux and secondorder slip effects is considered. By applying the similarity transformation, the governing equations are reconstructed into the similarity equations and the resulting equations are solved via shooting technique. Then, we implement a stability analysis in order to verify which solutions are stable and physically realizable. The eects of the magnetic parameter,moving parameter, mass transfer parameter, rstorder surface slip parameter, secondorder surface slip parameter and volume fraction of solid ferroparticles on the dimensionless velocity, temperature, skin friction and Nusselt numbers are discussed in the form of tabular and graphical presentation. For this present study, we consider the results based on three preferred ferroparticles, namely magnetite, cobalt ferrite and MnZn ferrite in water and kerosenebased fluids. The results display the existence of dual solutions for a plate moving towards the origin in which the rst solution is stable and physically realizable, while the second solution is not. Moreover, it is demonstrated that the magnetic, moving, mass transfer and slip effects together with the volume fraction of ferro fluids delay the boundary layer separation.
http://scientiairanica.sharif.edu/article_4343_873ba81985c4b34b0642924d6e811b64.pdf
MHD
Heat Transfer
ferro fluids
heat flux
secondorder slip
eng
Sharif University of Technology
Scientia Iranica
10263098
23453605
20180801
25
4
2198
2207
10.24200/sci.2017.4495
4495
Two and threedimensional numerical simulations of supersonic ramped inlet
R. Askari
1
M. R. Soltani
jzufniwp@scientiaunknown.non
2
Department of Aerospace Engineering, Sharif University, Tehran, Iran
Department of Aerospace Engineering, Sharif University, Tehran, Iran
Two Dimensional (2D) and Three Dimensional (3D) numerical simulations of an external compression supersonic ramped inlet for a free stream Mach number of 2 are presented. Comparison between numerical results and experimental data showed that multiblock structured gird using standard kε turbulence model gives acceptable results. The diffuser shape was then gradually varied to a circular one to encompass the Aerodynamic Interface Plane (AIP). It is observed that the 3D simulation predicted a more accurate static pressure distribution during the length of supersonic inlet and total pressure distribution at the AIP in comparison with the 2D one. Further, a better estimation of Shock Boundary Layer Interaction (SBLI), shock structure, and turbulent flow is predicted by the 3D simulation. It seems that, even though the 2D simulation scheme is widely used, it is a very weak method with low accuracy while the 3D simulation is more accurate and gives detailed flow field. Therefore; for cases where a detailed flow study along with an accurate prediction of flow parameters as well as the shock structure are required, the 3D numerical simulation must be applied.
http://scientiairanica.sharif.edu/article_4495_765ed05388763f449768edc228bf1af5.pdf
Ramped inlet
supersonic
external compression
numerical simulation
structural grid
eng
Sharif University of Technology
Scientia Iranica
10263098
23453605
20180801
25
4
2208
2217
10.24200/sci.2017.4345
4345
Numerical investigation into flow and mixed convective heat transfer of nonNewtonian impinging slot jets
R. Gharraei
1
A. Vejdani
2
L. Sasani
3
Mechanical Engineering Department, Azarbaijan Shahid Madani University, Tabriz, P.O. box 53714161, Iran
Mechanical Engineering Department, Azarbaijan Shahid Madani University, Tabriz, P.O. box 53714161, Iran
Mechanical Engineering Department, Azarbaijan Shahid Madani University, Tabriz, P.O. box 53714161, Iran
Mixed convection heat transfer of nonNewtonian impinging slot jets was investigated numerically. The simulation was performed using a temperature dependent powerlaw viscosity model. The results showed that for high Richardson numbers, a recirculation zone is created in the vicinity of impingement wall which prevents the jet stream from penetration into near wall region and decreases the Nusselt number around the stagnation point. The effects of jettoplate spacing, inlet Peclet number and the jet inlet width on the flow structure and heat transfer characteristics of impinging jet were studied using the numerical results. By decreasing jettoplate spacing and jet inlet width and increasing inlet Peclet number, the flow reversal in the vicinity of heated wall was disappeared and the local Nusselt number increases as a result of deeper penetration of jet stream the near wall region. Furthermore, the results indicated that the maximum local and average Nusselt numbers belong to the shearthinning jets with minimum inlet width and the minimum jettoplate spacing.
http://scientiairanica.sharif.edu/article_4345_c6580aa7ba3221969de01043f19ddb12.pdf
NonNewtonian fluid
Heat Transfer
OpenFOAM
Recirculation
Richardson number
eng
Sharif University of Technology
Scientia Iranica
10263098
23453605
20180801
25
4
2218
2232
10.24200/sci.2017.4346
4346
Numerical analysis of vibration and transient behaviour of laminated composite curved shallow shell structure: An experimental validation
Sushree S. Sahoo
1
Chetan K. Hirwani
2
Subrata K. Panda
3
Deeprodyuti Sen
4
Research Scholar, Department of Mechanical Engineering, National Institute of Technology, Rourkela: 769008, India
Research Scholar, Department of Mechanical Engineering, National Institute of Technology, Rourkela: 769008, India
Department of Mechanical Engineering, National Institute of Technology, Rourkela: 769008, India
Department of Mechanical Engineering, National Institute of Technology, Rourkela: 769008, India
The natural frequency and the transient responses of Carbon/Epoxy layered composite plate structure have been analysed with the help of two higherorder midplane kinematics models in this article. The mathematical formulation of the layered composite structure is further utilised to develop a computer programme in MATLAB15.0, to evaluate the said responses. The practical relevance of the present higherorder models has been established via comparing the present numerical results computed using suitable MATLAB computer code with the inhouse experimental test data. Additionally, the fundamental frequency and the transient responses of the carbon fibre reinforced epoxy composite plate structure are simulated via finite element package (ANSYS) with the help of ANSYS parametric design language (APDL) code. The simulated frequencies are compared with those of the present experimental and MATLAB results. Finally, the significance of the proposed higherorder kinematics has been established via solving a different kind of illustrations to investigate the influence of various geometrical and material parameter on the dynamic responses of layered composite structure and discussed in detail.
http://scientiairanica.sharif.edu/article_4346_90e132739924580bcbb864e389886867.pdf
experimental vibration
Carbon/Epoxy composite
HSDT
FEM
ANSYS
Transient behaviour