A. Mohammadi, A. Jazayeri, M. Ziabasharhagh,
Volume 2, Issue 4 (10-2012)
Abstract
Porous media has interesting features in compared with free flame combustion due to the extended of the
lean flammability limits and lower emissions. Advanced new generation of internal combustion (IC)
engines are expected to have far better emissions levels both gaseous and particulate matter, at the same
time having far lower fuel consumption on a wide range of operating condition. These criteria could be
improved having a homogeneous combustion process in an engine. Present work considers simulation of
direct fuel injection in an IC engine equipped with a chemically inert porous medium (PM), having
cylindrical geometry that is installed in cylinder head to homogenize and stabilize the combustion process.
A numerical study of a 3D model, PM engine is carried out using a modified version of the KIVA-3V code.
Since there is not any published material for PM-engines in literature, the numerical results for combustion
waves propagation within PM are compared with experimental data available in the literature for a lean
mixture of air and methane under filtration in packed bed, the accuracy of results are very promising. For
PM-engine simulation the methane fuel is injected directly through a hot PM which is mounted in cylinder
head. Therefore volumetric combustion occurs as a result within PM and in-cylinder. The effects of
injection timing on mixture formation, pressure and temperature distribution in both phases of PM and incylinder
fluid together with combustion emissions such as CO and NO are studied in detail for an important
part of the cycle.
A. R. Noorpoor, A. Sadighzadeh, H. Habibnejad,
Volume 2, Issue 4 (10-2012)
Abstract
Diesel exhaust particles are a complex mixture of thousands of gases and fine substances that contain more
than 40 different environmental contaminants. Being exposed to these exhaust particles (called soot) can
cause lung damage and respiratory problems. Diesel particulate filters are used in many countries for
mobile sources as a legal obligation to decrease harmful effect of these fine particles. The size range of
these particles is varied from 0.01 to 1 µm. Moreover, it takes a long time to be settled when they are
outspread in atmosphere. In this paper, homogeneous plane standing waves are used to coagulate nano
particles in order to achieve larger size which has a better gravitational settling. It means that fine particles
are converted into a large one. Theoretical mechanisms are studied which led to experimental results in
155(db) and 160 (db). The results show that acoustic precipitators have a good performance in removing
fine particles in diesel exhaust. Additionally, they indicate that at high pressure levels, the system has high
efficiency for removing fine particles
A. Ghaffari, A. Khodayari, S. Arvin, F. Alimardani,
Volume 2, Issue 4 (10-2012)
Abstract
The lane change maneuver is among the most popular driving behaviors. It is also the basic element of
important maneuvers like overtaking maneuver. Therefore, it is chosen as the focus of this study and novel
multi-input multi-output adaptive neuro-fuzzy inference system models (MANFIS) are proposed for this
behavior. These models are able to simulate and predict the future behavior of a Driver-Vehicle-Unit in the
lane change maneuver for various time delays. To design these models, the lane change maneuvers are
extracted from the real traffic datasets. But, before extracting these maneuvers, several conditions are
defined which assure the extraction of only those lane change maneuvers that have a smooth and uniform
trajectory. Using the field data, the outputs of the MANFIS models are validated and compared with the
real traffic data. In addition, the result of these models is compared with the result of other trajectory
models. This comparison provides a better chance to analyze the performance of these models. The
simulation results show that these models have a very close compatibility with the field data and reflect the
situation of the traffic flow in a more realistic way.
M. Hakimollahi, S. G. Jalali Naini, M. Bagherpour, S. Jafari, A. Shahmoradi,
Volume 2, Issue 4 (10-2012)
Abstract
In recent years, the balanced score card (BSC) has been the focus of considerable methodology for strategic
cost management in management accounting area since it was originally proposed by Kaplan ,R.S. and
Norton, D.P. in 1992. BSC is an approach to performance measurement based on both financial and nonfinancial
information from four perspectives which are called financial, customer, internal business process,
and learning and growth, in order to balance the traditional financial performance system by several
grouping of performance measures: short-term and long-term, internal and external, and current and future.
Over time, it has been developed to a strategic management system from a comprehensive performance
measure, and used in many organizations such as business, hospital, and autonomy in many countries. In
this paper, we propose a general model based on BSC by introducing fuzzy inference mechanism. From
this, specialists’ knowledge and experience can be effectively reflected during the construction of the
practical model. Then we illustrate a practical example for an Automotive Manufacturing Co.
S. R. Das, D. Dhupa, A. Kumar,
Volume 3, Issue 1 (3-2013)
Abstract
Turning of hardened steels using a single point cutting tool has replaced the cylindrical grinding now as it
offers attractive benefits in terms of lower equipment costs, shorter set up time, fewer process setups,
higher material removal rate, better surface quality and elimination of cutting fluids compared to cylindrical
grinding. In order to obtain desired surface quality by machining, proper machining parameters selection is
essential. This can be achieved by improving quality and productivity in metal cutting industries. The
present study is to investigate the effect of machining parameters such as cutting speed, feed and depth of
cut on surface roughness during dry turning of hardened AISI 4340 steel with CVD
(TiN+TiCN+Al2O3+ZrCN) multilayer coated carbide inserts. A full factorial design of experiment is
selected for experimental planning and the analysis of variance (ANOVA) has been employed to analyze
the significant machining parameters on surface roughness during turning. The results showed that feed
(60.85%) is the most influencing parameter followed by cutting speed (24.6%) at 95% confidence level.
And the two-level interactions of feed-cutting speed (F*V), depth of cut-feed (D*F) and depth of cutcutting
speed (D*V) are found the significant effects on surface roughness in this turning process.
Moreover, the relationship between the machining parameters and performance measure i.e. surface
roughness has been modeled using multiple regression analysis.
S.a. Yousefsani, J. Rezaeepazhand, S.a. Maghami,
Volume 3, Issue 1 (3-2013)
Abstract
Material properties and geometry are two important design parameters which their effects should be
considered in a crashworthiness analysis. In this paper, the axial impact of metallic and hybrid energy
absorbing thin-walled tubes with poly-gonal cross-section is simulated using LS-DYNA software. The
combined effects of changing the geometry and material properties on the mass specific energy absorption
(MSEA) as well as the mean and maximum crush forces are investigated. To compare the results, all
metallic tubes have identical thickness, length, and circumference. The hybrid tubes are made of the same
metallic tubes which are reinforced with special composite overlays. These materials are intentionally
selected in such a way that the effects of yield strength and Young’s modulus can be separately
investigated. The results show that, in contrast with the current belief, there are some metallic and hybrid
tubes with non- circular cross-section shapes, which have better mass specific energy absorption
capabilities than the circular ones during the impact.
M. Azadi, M. Baloo, G. H. Farrahi, S. M. Mirsalim,
Volume 3, Issue 1 (3-2013)
Abstract
In the present paper, a complete literatures review of thermal barrier coating applications in diesel engines
is performed to select a proper type and to find coating effects. The coating system has effects on the fuel
consumption, the power and the combustion efficiency, pollution contents and the fatigue lifetime of engine
components. Usually there are several beneficial influences by applying ceramic layers on the combustion
chamber, including the piston, the cylinder head, the cylinder block, intake and exhaust valves by using a
plasma thermal spray method. Several disadvantages such as producing nitrogen oxides also exist when a
coating system is used. In this article, all effects, advantages and disadvantages of thermal barrier coatings
are investigated based on presented articles.
M.h. Shojaeefard, R. Talebitooti, S. Yarmohammadisatri, M. Torabi,
Volume 3, Issue 1 (3-2013)
Abstract
In this paper, a method based on binary-coded genetic algorithm is proposed to explore an optimization method, for obtaining an optimal elliptical tank. This optimization method enhances the rollover threshold of a tank vehicle, especially under partial filling conditions. Minimizing the overturning moment imposed on the vehicle due to c.g. height of the liquid load, lateral acceleration and cargo load shift are properly applied. In the process, the width and height of tanker are assumed as constant parameters. Additionally, considering the constant cross-sectional area, an optimum elliptical tanker of each filling condition is presented to provide more roll stability. Moreover, the magnitudes of lateral and vertical translation of the cargo within the proposed optimal cross section under a constant lateral acceleration field are compared with those of conventional elliptical tank to demonstrate the performance potentials of the optimal shapes. Comparing the vehicle rollover threshold of proposed optimal tank with that of currently used elliptical and circular tank reveals that the optimal tank is improved approximately 18% higher than conventional one.
H. Pashazadeh, A. Masoumi, J. Teimournezhad,
Volume 3, Issue 1 (3-2013)
Abstract
The objective of this study was to develop a numerical model for the prediction of temperature distribution,
effective plastic strain distribution, and especially material flow in friction stir welding of copper plates.
The DEFORM-3D software was used by incorporating a lagrangian incremental formulation. Threedimensional
results of the material flow pattern which were extracted using the point tracking are in good
agreement with the experiment. It was shown that the main part of material flow occurs near the top
surface. Material near the top surface at the behind of tool stretches from retreating side towards advancing
side which leads to non-symmetrical shape of the stir zone. The stir zone shape in FSW of copper alloys,
which was predicted by simulation, does not lean completely towards any sides of welding line.
M. A. Saeedi, R. Kazemi,
Volume 3, Issue 1 (3-2013)
Abstract
In this study, stability control of a three-wheeled vehicle with two wheels on the front axle, a three-wheeled
vehicle with two wheels on the rear axle, and a standard four-wheeled vehicle are compared. For vehicle
dynamics control systems, the direct yaw moment control is considered as a suitable way of controlling the
lateral motion of a vehicle during a severe driving maneuver. In accordance to the present available
technology, the performance of vehicle dynamics control actuation systems is based on the individual
control of each wheel braking force known as the differential braking. Also, in order to design the vehicle
dynamics control system the linear optimal control theory is used. Then, to investigate the effectiveness of
the proposed linear optimal control system, computer simulations are carried out by using nonlinear twelvedegree-
of-freedom models for three-wheeled cars and a fourteen-degree-of-freedom model for a fourwheeled
car. Simulation results of lane change and J-turn maneuvers are shown with and without control
system. It is shown that for lateral stability, the three wheeled vehicle with single front wheel is more stable
than the four wheeled vehicle, which is in turn more stable than the three wheeled vehicle with single rear
wheel. Considering turning radius which is a kinematic property shows that the front single three-wheeled
car is more under steer than the other cars.
M. Eftekhar, A. Keshavarz, A. Ghasemian, J. Mahdavinia,
Volume 3, Issue 1 (3-2013)
Abstract
Running the industrial components at a proper temperature is always a big challenge for engineers. Internal
combustion engines are among these components in which temperature plays a big role in their
performance and emissions. With the development of new technology in the fields of ‘nano-materials’ and
‘nano-fluids’, it seems very promising to use this technology as a coolant in the internal combustion
engines. In this study, a nano-fluid (Al2O3-Water/Ethylene Glycol (EG)) is used as an engine coolant along
with an optimized heat exchanger to reduce the warm-up timing. The effect of nano-fluid concentration is
considered here by using their corresponding governing equations, such as momentum and energy. The
engine coolant thermal behavior calculation is carried out based on the lumped method. The obtained
results indicated that using different percentage of nano-fluid mixtures (by volume), such as Al2O3-
Water/EG as engine coolant enhances the heat transfer coefficient and reduces the warm-up timing which,
in turn, results in reduced emissions and fuel consumption.
S. K. Kamboj, M. N. Karimi,
Volume 3, Issue 2 (6-2013)
Abstract
Alcohols have been used as a fuel for engines since 19th century. Among the various alcohols, ethanol and
methanol are known as the most suited renewable, bio-based and ecofriendly fuel for spark-ignition (SI)
engines. The most attractive properties of ethanol and methanol as an SI engine fuel are that it can be
produced from renewable energy sources such as sugar, cane, cassava, many types of waste biomass
materials, corn and barley. In addition, ethanol has higher evaporation heat, octane number and
flammability temperature therefore it has positive influence on engine performance and reduces exhaust
emissions. In this study, the effects of unleaded iso-octane, unleaded iso-octane–ethanol blend (E10) and
isooctane-methanol blend (M10) on engine performance were investigated experimentally in a single
cylinder four-stroke spark-ignition engine. The tests were performed by varying the throttle position,
engine speed and loads. Three sets of observations were recorded at (1301 rpm, 16.8 Kg load), (1468 rpm,
15.8 Kg load) and (1544 rpm, 10 Kg load) for all tested fuels. The results of the engine test showed that IP,
IMEP, Volumetric efficiency and thermal efficiency was higher for the E10 fuel and BSFC was lower. In
general, most suited blend for SI engines has been specified as a blend of 10% ethanol. It was also observed
that better performance was recorded during second set of observation for all the tested fuels. It was also
found that ethanol–gasoline blends allow increasing compression ratio (CR) without knock occurrence.
M. Iranmanesh,
Volume 3, Issue 2 (6-2013)
Abstract
In this study, various percentage of DEE was added to the optimum selected ethanol-diesel blend (D-E10)
and optimized its blending ratio to overcome the poor ignition quality of ethanol when utilized in a single
cylinder DI diesel engine. Some physicochemical properties of test fuels such as heating value, viscosity,
and density and distillation profile were determined in accordance to the ASTM standards. The heating
value of the blends was reduced with addition of DEE. Front-end volatility of the blends was improved by
addition of DEE, which in turn improves the cold starting property. The uncertainty associated with
measurements was also measured. The data were analyzed statistically for 95% confidence level. The
results have shown that addition of biofuels, ethanol and diethyl ether, have improved the combustion and
emissions characteristics of the engine. Addition of ethanol and DEE improved smoke and NOx emissions
simultaneously. It was found the 8% DEE add to the D-E10 blend is the optimum combination based on the
performance and emission analysis with the exception of smoke opacity in which 15% DEE addition made
the lowest smoke opacity. At this optimum ratio the minimum peak heat release rate, the lowest NOx
emissions and the maximum BTE were occurred at full load condition. Meanwhile the lowest level of CO
and HC emissions were obtained at all the load conditions with the same blending ratio.
A. Ghaffari, A. Khodayari, F. Alimardani, H. Sadati,
Volume 3, Issue 2 (6-2013)
Abstract
Overtaking a slow lead vehicle is a complex maneuver because of the variety of overtaking conditions and
driver behavior. In this study, two novel prediction models for overtaking behavior are proposed. These
models are derived based on multi-input multi-output adaptive neuro-fuzzy inference system (MANFIS).
They are validated at microscopic level and are able to simulate and predict the future behavior of the
overtaking vehicle in real traffic flow. In these models, the kinematic features of Driver-Vehicle-Units
(DVUs) such as distance, velocity, and acceleration are used. Unlike the previous models, where some
variables of the two involved vehicles are considered to be constant, in this paper, instantaneous values of
the variables are considered. The first model predicts the future value of the longitudinal acceleration and
the movement angle of the overtaking vehicle. The other model predicts the overtaking trajectory for the
overtaking vehicle. The second model is designed for two different vehicle classes: motorcycles and autos.
Also, the result of the trajectory prediction model is compared with the result of other models. This
comparison provides a better chance to analyze the performance of this model. Using the field data, the
outputs of the MANFIS models are validated and compared with the real traffic dataset. The simulation
results show that these two MANFIS models have a very close compatibility with the field data and reflect
the situation of the traffic flow in a more realistic way. These models can be used for all types of drivers
and vehicles and also in other roads and are not limited to certain types of situations. The proposed models
can be employed in ITS applications and the like.
B. Jafari, D. Domiri Ganji,
Volume 3, Issue 2 (6-2013)
Abstract
Air pollution is one of the major issues about the diesel engines in todays' world. It is a special concern in
those areas that have difficulty meeting health-based outdoor air quality standards. Natural gas has low
emission and resource abundance and also conventional compression ignition engine can be easily
converted to a dual fuel mode to use natural gas as main fuel and diesel as pilot injection. The main object
of this work is to investigate the effect of number of injector nozzle hole on the combustion and exhaust
emission in a gas engine ignited with diesel fuel. We use one and three-dimensional simulation in parallel
way in order to analyze the performance and combustion process of a dual fuel engine. The experimental
results have also reported and compared with the simulated data.
S. Jafarmadar, M. Khanbabazadeh,
Volume 3, Issue 2 (6-2013)
Abstract
In the present work, multidimensional modeling of open-cycle process of OM355 engine was developed.
Calculations for computational mesh were carried out. The results of the model were validated by
experimentally measured in-cylinder pressure and the good agreement between calculations and
measurements approved the trustworthy of numerical code. Results included pressure, temperature,
emission and Rate of heat release diagrams were represented for the full cycle. Furthermore local flow field
velocity vectors were indicated. The results show the importance of open-cycle simulations in automotive
researches.
A. Fazli,
Volume 3, Issue 2 (6-2013)
Abstract
In this paper, the optimum shape of Tailor-Welded Blanks (TWB) is investigated. The optimization is
performed for two different case studies. The first example is deep drawing of a TWB with dissimilar
materials and uniform thicknesses and the next example is deep drawing of a TWB with similar materials
and non-uniform thicknesses. The effect of blank optimization on the weld line movement is investigated.
Also the effect of weld line location on the blank optimization and weld line movement is examined.
A. Khalkhali, V. Agha Hosseinali Shirazi, M. Mohseni Kabir,
Volume 3, Issue 2 (6-2013)
Abstract
One of the most important structural components of engine compartment assembly in a car body is the Srail. S-rails has significant role in absorbing energy during crash events and therefore it is designed for efficient behavior in such conditions. Driving the peak crushing force of the S-rails is one of the important objectives in the design process of such structures. Peak crushing force is exactly the force applied to the downstream components and then will be transferred to the cabin of vehicle. In this paper, closed form solution is performed to drive the peak crushing force of the S-rails. Results of such analytical model finally are compared with the results of finite element simulation. Good agreement between such results shows the accuracy of the proposed analytical model.
M. Baghaeian, A. A. Akbari,
Volume 3, Issue 3 (9-2013)
Abstract
In this paper, the enhancement of vehicle stability and handling is investigated by control of the active
geometry suspension system (AGS). This system could be changed through control of suspension mounting
point’s position in the perpendicular direction to wishbone therefore the dynamic is alternative and
characteristics need to change. For this purpose, suitable controller needs to change mounting point’s
position in limit area. Adaptive fuzzy control able to adjust stability and handling characteristics in all
conditions. Also, simple controller such as proportional-integral-derivative (PID) versus adaptive fuzzy
have been used that submit intelligent controllers. The three of freedom model (3DOF) in vehicle handling
is validated with MATLAB and CarSim software. The results show that the steady state response of the
adaptive fuzzy controller has been closed to desired yaw and roll angle has been enhanced about %20. In
cases of lateral velocity and side slip angle have the same condition that it shows the stability has been
improved. The control effort of PID needs to change very high that this response is not good physically,
while control effort in adaptive fuzzy is less than 50 mm.
M. H. Shojaeefard, M. Tahani, M. M. Etghani, M. Akbari,
Volume 3, Issue 3 (9-2013)
Abstract
Cooled exhaust gas recirculation is emerging as a promising technology to address the increasing demand for fuel economy without compromising performance in turbocharged spark injection engines. The objectives of this study are to quantify the increase in knock resistance and to decrease the enrichment and emission at high load. For this purpose four stroke turbo charged Spark Ignition engine (EF7-TC) including its different systems such as inlet and exhaust manifold, exhaust pipe and engine geometry are modeled using GT Power Software. As predicted, using cooled EGR at high load enabled operation at lambda near to one with the same serial engine performances, which offers substantial advantages Such As BSFC reduction (up to 14%), and emission reduction (CO, NOx).