Sharif University of TechnologyScientia Iranica1026-309816220090401Design of a Mathematical Model to Minimize Air Pollution Caused by Job Trips in Mega Cities3000ENM.ShafiepourFaculty of Engineering,University of TehranM.MahmoudiDepartment of Science,University of TehranM.AbbaspourDepartment of Mechanical Engineering,Sharif University of TechnologyT.DanaSchool of Energy Engineering,Azad UniversityJournal Article20090603Abstract. Urban transportation is one of the main sources of air pollution in mega cities, and urban
job related trips can e ectively in
uence the state of air quality. Tehran, the capital of Iran, with a
population of 7.3 million, was selected for this study. The present model is designed to investigate the
e ect on trac of the business working hours of di erent occupations and, as a result, on the status of
air pollution. Daily job, non-job and recreational trips using the present vehicle
eet is a major factor
a ecting air pollution in Tehran. In the context of the present study, the necessary information was
utilized to de ne some relations between job trips and pollutant emissions. The result showed that a
proper adjustment of opening hours for di erent jobs can result in a reduction of pollutant emissions by
as much as 20% during daily trac peak hours.https://scientiairanica.sharif.edu/article_3000_25de5e943cd52701d07453d8898b5f02.pdfSharif University of TechnologyScientia Iranica1026-309816220090401Free Vibration Analysis of Rotating Laminated Cylindrical Shells Under Di erent Boundary Conditions Using a Combination of the Layerwise Theory and Wave Propagation Approach3001ENM.T.AhmadianDepartment of Mechanical Engineering,Sharif University of TechnologyJournal Article20090606Abstract. In this paper, vibration analysis of rotating laminated composite cylindrical shells using
a combination of the layerwise theory and wave propagation approach is investigated. This combination
enables us to study all the conventional boundary conditions in our analysis. Results obtained have been
compared with those available in the literature and a good agreement has been observed. In contrast
to the Equivalent Single Layer theories (ESL), the layerwise theory is constructed on the basis of C0-
continuity through the laminate thickness. For the surface of the shell, a displacement eld based on
the wave propagation approach is proposed. The e ect of Coriolis and centrifugal accelerations on the
circumferential and longitudinal modes is investigated. At high rotational speeds, the stationary frequency
is smaller than both the forward and backward frequencies and this di erence increases with the increase
of rotational speed. The in
uence of boundary conditions on the frequencies is more signi cant at lower
circumferential modes but at higher modes the e ect of the boundary condition is in nitesimal.https://scientiairanica.sharif.edu/article_3001_6b17509cc342296326b51e9db030b7c1.pdfSharif University of TechnologyScientia Iranica1026-309816220090401Traveling Wave Solutions of the Sine-Gordon and the Coupled Sine-Gordon Equations Using the Homotopy-Perturbation Method3002END.D.GanjiDepartment of Mechanical Engineering,Abhar Islamic Azad UniversityA.SadighiDepartment of Mechanical Engineering,University of AlbertaB.GanjaviDepartment of Civil Engineering,University of AlbertaJournal Article20090606Abstract. In this research, the Homotopy-Perturbation Method (HPM) has been used for solving sine-
Gordon and coupled sine-Gordon equations, which have a wide range of applications in physics. HPM
deforms a dicult problem into a simple one which can be easily solved. The results obtained by HPM are
then compared with those of the Adomian Decomposition Method (ADM). The method has been shown to
e ectively, easily and accurately solve a large class of nonlinear problems with approximations converging
rapidly to accurate solutions.https://scientiairanica.sharif.edu/article_3002_febfe68a65cc38d579da78f1d44623d4.pdfSharif University of TechnologyScientia Iranica1026-309816220090401The E ect of Wake Flow and Skew Angle on the Ship Propeller Performance3003ENH.GhassemiDepartment of Marine Technology,Amirkabir University of TechnologyJournal Article20090606Abstract. This paper provides an investigation into the in
uence of wake and skew on a ship propeller
performance, based on the potential Boundary Element Method (BEM). Two types of in
ow wake from a
ship (i.e. Seiun-Maru and MS689) have been investigated for two propeller types; a Conventional Propeller
(CP) and a Highly Skewed Propeller (HSP). The computed results include pressure distribution, open
water characteristics and thrust
uctuation for one blade and for all blades of the propeller. Calculations
of the unsteady pressure distributions, thrust and torque are in good agreement with experimental data.
In addition, the e ect of propeller skew angle on the performance of thrust and torque, is investigated.https://scientiairanica.sharif.edu/article_3003_8fe0197aa7f5dedeb795fd7722315588.pdfSharif University of TechnologyScientia Iranica1026-309816220090401Simulation of Turbulent Flow Through Porous Media Employing a v2f Model3004ENS.Kazemzadeh HannaniDepartment of Mechanical Engineering,Sharif University of TechnologyR.Bahoosh KazerooniDepartment of Mechanical Engineering,Sharif University of TechnologyJournal Article20090606Abstract. In this article, a v2f model is employed to conduct a series of computations of incompressible
ow in a periodic array of square cylinders simulating a porous media. A Galerkin/least-squares nite
element formulation employing equal order velocity-pressure elements is used to discretize the governing
equations. The Reynolds number is varied from 1000 to 84,000 and di erent values of porosities are
considered in the calculations. Results are compared to the available data in the literature. The v2f model
exhibits superior accuracy with respect to k????" results and is closer to LES calculations. The macroscopic
pressure gradients for all porosities studied showed a good agreement with Forchheimer-extended Darcy's
law in the range of large Reynolds numbers.https://scientiairanica.sharif.edu/article_3004_d262d099b668f8d9d980fcf69f2ffd37.pdfSharif University of TechnologyScientia Iranica1026-309816220090401Spectator Model in D Meson Decays3005ENH.MehrbanDepartment of Physics,Semnan UniversityJournal Article20090606Abstract. In this research, the e ective Hamiltonian theory is described and applied to the calculation
of current-current (Q1;2) and QCD penguin (Q3; ;6) decay rates. The channels of charm quark decay in
the quark levels are: c ! dud, c ! dus, c ! sud and c ! sus where the channel c ! sud is dominant.
The total decay rates of the hadronic of charm quark in the e ective Hamiltonian theory are calculated.
The decay rates of D meson decays according to Spectator Quark Model (SQM) are investigated for the
calculation of D meson decays. It is intended to make the transition from decay rates at the quark level to
D meson decay rates for two body hadronic decays, D ! h1h2. By means of that, the modes of nonleptonic
D ! PV , D ! PP, D ! V V decays where V and P are light vector with JP = 0???? and pseudoscalar
with JP = 1???? mesons are analyzed, respectively. So, the total decay rates of the hadronic of charm quark
in the e ective Hamiltonian theory, according to Colour Favoured (C-F) and Colour Suppressed (C-S) are
obtained. Then the amplitude of the Colour Favoured and Colour Suppressed (F-S) processes are added
and their decay rates are obtained. Using the spectator model, the branching ratio of some D meson
decays are derived as well.https://scientiairanica.sharif.edu/article_3005_08c853f9ce54fcd4416c2691d3a387be.pdfSharif University of TechnologyScientia Iranica1026-309816220090401Micro Resonator Nonlinear Dynamics Considering Intrinsic Properties3006ENH.SayyaadiDepartment of Mechanical Engineering,Sharif University of TechnologyM.A.TadayonDepartment of Mechanical Engineering,Sharif University of TechnologyJournal Article20090606Abstract. One of the most important phenomena to a ect the motion behaviour of Micro Resonators
is their thermal dependency. This has recently received the attention of researchers widely. A thermal
phenomenon has two main e ects, the rst is damping, due to internal friction, and the second is
softening, due to Young's modulus-temperature relationship. In this research work, some theoretical and
experimental reported results are used to make a proper model, including thermal phenomena. Two
Lorentzian functions are used to describe the restoring and damping forces caused by thermal phenomena.
In order to emphasize the thermal e ects, a nonlinear model of the MEMS, considering capacitor
nonlinearity and mid-plane stretching, has been used. The responses of the system are developed by
employing a multiple time scale perturbation method on a non-dimensionalized form of the equations.
Frequency response, resonance frequency and peak amplitude are examined by varying the dynamic
parameters of the modelled system. Finally, Fuzzy Generalized Cell Mapping (FGCM) is introduced
and applied to the Micro Resonator's dynamical system behaviour. It is then concluded as to how the
model uncertainties and di erent initial conditions can a ect the working domain of the system and/or
make it pull in instabilities. At the end, it can be seen that FGCM is a useful method for monitoring the
working regions of Micro Resonators, while varying system parameters.https://scientiairanica.sharif.edu/article_3006_4932296fab63e45befdf4df7d90e3bc4.pdfSharif University of TechnologyScientia Iranica1026-309816220090401Parametric Study of Hot Rolling Process by the Finite Element Method3007ENA.R.ShahaniDepartment of Mechanical Engineering,Khajeh Nasire Toosi University of TechnologyS. A.NodamaieDepartment of Mechanical Engineering,Khajeh Nasire Toosi University of TechnologyI.SalehiniaDepartment of Mechanical Engineering,Khajeh Nasire Toosi University of TechnologyJournal Article20090606Abstract. In the present investigation, a hot rolling process of AA5083 aluminum alloy is simulated.
The approach is based on the thermo-mechanical analysis of the problem using the Finite Element Method
(FEM). The temperature distribution in the roll and the slab, the stress, strain and strain rate elds, are
extracted throughout a transient analysis of the process. The main hypotheses adopted in the formulation
are: The thermo-viscoplastic behavior of the material, expressed by the Perzyna constitutive equation and
rolling under plane-deformation conditions. The main variables that characterize the rolling process, such
as the geometry of the slab, load, rolling speed, percentage of thickness reduction, initial thickness of the
slab and friction coecient, have been expressed in a parametric form, giving good
exibility to the model.
The congruence of the results has been evaluated using experimental and theoretical data available in the
literature.https://scientiairanica.sharif.edu/article_3007_025c18f907c08b25af1cc556524c79e0.pdfSharif University of TechnologyScientia Iranica1026-309816220090401Direct Design of Branched Ducts3008ENA.AshrafizadehDepartment of Mechanical Engineering,Khajeh Nasire Toosi University of TechnologyM.Taiebi-RahniDepartment of Aerospace Engineering,Sharif University of TechnologyF.GhadakDepartment of Aerospace Engineering,I.P.M.Journal Article20090606Abstract. A fully coupled formulation of thermo-
uid shape design problems has recently been
developed in which the unknown nodal coordinates appear explicitly in the formulation of the problem.
This direct design" approach is, in principle, generally applicable and has been successfully applied in the
context of potential and Euler
ow models.This paper focuses on the direct design of ducts using the ideal
ow model and may be considered as an addendum to the paper entitled Direct Design of Ducts" [1].
However, a cell-vertex nite volume method is used and a di erent boundary condition implementation
technique is applied, as compared to the method presented in the previous paper. The other new feature
is that a non-linear algebraic method is used for grid generation. The method is also proved to be capable
of designing complex
ow passages, such as branched ducts.https://scientiairanica.sharif.edu/article_3008_e0e25cdc1622d650fc7150a54b89435e.pdf