Abstract: Proof of controlling crack width is a basic condition
for securing suitable performance in serviceability limit state. The
cracking in concrete can occur at any time from the casting of time to
the years after the concrete has been set in place. Most codes struggle
with offering procedure for crack width calculation. There is lack in
availability of design charts for designers to compute crack width
with ease. The focus of the study is to utilize design charts and
parametric equations in calculating crack width with minimum error.
The paper contains a simplified procedure to calculate crack width
for reinforced concrete (RC) sections subjected to bending with axial
tensile force following the guidelines of Euro code [DS EN-1992-1-1
& DS EN-1992-1-2]. Numerical examples demonstrate the
application of the suggested procedure. Comparison with parallel
analytical tools supports the validity of result and show the
percentage deviation of crack width in both the procedures. The
technique is simple, user friendly and ready to evolve for a greater
spectrum of section sizes and materials.
Abstract: Electric vehicles are one of the most complicated
electric devices to simulate due to the significant number of different
processes involved in electrical structure of it. There are concurrent
processes of energy consumption and generation with different
onboard systems, which make simulation tasks more complicated to
perform. More accurate simulation on energy consumption can
provide a better understanding of all energy management for electric
transport. As a result of all those processes, electric transport can
allow for a more sustainable future and become more convenient in
relation to the distance range and recharging time. This paper
discusses the problems of energy consumption simulations for
electric vehicles using different software packages to provide ideas
on how to make this process more precise, which can help engineers
create better energy management strategies for electric vehicles.
Abstract: Wet scrubbers have found widespread use in cleaning
contaminated gas streams because of their ability to remove
particulates and based on the applications of scrubbing of marine
engine exhaust gases by spraying sea-water. In order to examine the
flow characteristics inside the scrubber, the model is designated with
flow properties of hot air and water sprayer. The flow dynamics of
evaporation of hot air by the injection of water droplets is the key
factor considered in this paper. The flow behavior inside the scrubber
was investigated from the previous works and to sum up the
evaporation rate with respect to the concentration of water droplets are
predicted to bring out the competent modelling. The numerical
analysis using CFD facilitates in understanding the problem better and
empathies the behavior of the model over its entire operating envelope.
Abstract: Presently, engine cooling pump is driven by toothed
belt. Therefore, the pump speed is dependent on engine speed which
varies their output. At normal engine operating conditions (Higher
RPM and low load, Higher RPM and high load), mechanical water
pumps in existing engines are inevitably oversized and so the use of
an electric water pump together with state-of-the-art thermal
management of the combustion engine has measurable advantages.
Demand-driven cooling, particularly in the cold-start phase, saves
fuel (approx 3 percent) and leads to a corresponding reduction in
emissions. The lack of dependence on a mechanical drive also results
in considerable flexibility in component packaging within the engine
compartment. This paper describes the testing and comparison of
existing mechanical water pump with that of the electric water pump.
When the existing mechanical water pump is replaced with the new
electric water pump the percentage gain in system efficiency is also
discussed.
Abstract: The Simulation based VLSI Implementation of
FELICS (Fast Efficient Lossless Image Compression System)
Algorithm is proposed to provide the lossless image compression and
is implemented in simulation oriented VLSI (Very Large Scale
Integrated). To analysis the performance of Lossless image
compression and to reduce the image without losing image quality
and then implemented in VLSI based FELICS algorithm. In FELICS
algorithm, which consists of simplified adjusted binary code for
Image compression and these compression image is converted in
pixel and then implemented in VLSI domain. This parameter is used
to achieve high processing speed and minimize the area and power.
The simplified adjusted binary code reduces the number of arithmetic
operation and achieved high processing speed. The color difference
preprocessing is also proposed to improve coding efficiency with
simple arithmetic operation. Although VLSI based FELICS
Algorithm provides effective solution for hardware architecture
design for regular pipelining data flow parallelism with four stages.
With two level parallelisms, consecutive pixels can be classified into
even and odd samples and the individual hardware engine is
dedicated for each one. This method can be further enhanced by
multilevel parallelisms.
Abstract: Starting in 2020, an EU-wide CO2-limitation of
95 g/km is scheduled for the average of an OEMs passenger car fleet.
Taking that into consideration additional improvement measures of
the Diesel cycle are necessary in order to reduce fuel consumption
and emissions while boosting, or at the least, keeping performance
values at the same time.
The present article deals with the possibilities of an optimized
air/water charge air cooler, also called iCAC (indirect Charge Air
Cooler) for a Diesel passenger car amongst extreme-boundary
conditions. In this context, the precise objective was to show the
impact of improved intercooling with reference to the engine working
process (fuel consumption and NOx-emissions). Several extremeboundaries
- e.g. varying ambient temperatures or mountainous
routes - that will become very important in the near future regarding
RDE (Real Driving emissions) were subject of the investigation.
With the introduction of RDE in 2017 (EU6c measure), the
controversial NEDC (New European Driving Cycle) will belong to
the past and the OEMs will have to avoid harmful emissions in any
conceivable real life situation.
This is certainly going to lead to optimization-measurements at the
powertrain, which again is going to make the implementation of
iCACs, presently solely used for the premium class, more and more
attractive for compact class cars. The investigations showed a benefit
in FC between 1 and 3% for the iCAC in real world conditions.
Abstract: Particles exhausted from cars have adverse impacts on
human health. The study developed a three-dimensional particle
dispersion numerical model including particle coagulation to simulate
the particle concentration distribution under idling conditions in a
residential underground garage. The simulation results demonstrate
that particle disperses much faster in the vertical direction than that in
horizontal direction. The enhancement of particle dispersion in the
vertical direction due to the increase of cars with engine running is
much stronger than that in the car exhaust direction. Particle dispersion
from each pair of adjacent cars has little influence on each other in the
study. Average particle concentration after 120 seconds exhaust is
1.8-4.5 times higher than the initial total particles at ambient
environment. Particle pollution in the residential underground garage
is severe.
Abstract: Over the last few decades, oilfield service rolling
equipment has significantly increased in weight, primarily because of
emissions regulations, which require larger/heavier engines, larger
cooling systems, and emissions after-treatment systems, in some
cases, etc. Larger engines cause more vibration and shock loads,
leading to failure of electronics and control systems.
If the vibrating frequency of the engine matches the system
frequency, high resonance is observed on structural parts and mounts.
One such existing automated control equipment system comprising
wire rope mounts used for mounting computers was designed
approximately 12 years ago. This includes the use of an industrialgrade
computer to control the system operation. The original
computer had a smaller, lighter enclosure. After a few years, a newer
computer version was introduced, which was 10 lbm heavier. Some
failures of internal computer parts have been documented for cases in
which the old mounts were used. Because of the added weight, there
is a possibility of having the two brackets impact each other under
off-road conditions, which causes a high shock input to the computer
parts. This added failure mode requires validating the existing mount
design to suit the new heavy-weight computer.
This paper discusses the modal finite element method (FEM)
analysis and experimental modal analysis conducted to study the
effects of vibration on the wire rope mounts and the computer. The
existing mount was modelled in ANSYS software, and resultant
mode shapes and frequencies were obtained. The experimental modal
analysis was conducted, and actual frequency responses were
observed and recorded.
Results clearly revealed that at resonance frequency, the brackets
were colliding and potentially causing damage to computer parts. To
solve this issue, spring mounts of different stiffness were modeled in
ANSYS software, and the resonant frequency was determined.
Increasing the stiffness of the system increased the resonant
frequency zone away from the frequency window at which the engine
showed heavy vibrations or resonance. After multiple iterations in
ANSYS software, the stiffness of the spring mount was finalized,
which was again experimentally validated.
Abstract: Systems Engineering plays a key role during industrial
product development of complex technical systems. The need for
systems engineers in industry is growing. But there is a gap between
the industrial need and the academic education. Normally the
academic education is focused on the domain specific design,
implementation and testing of technical systems. Necessary systems
engineering expertise like knowledge about requirements analysis,
product cost estimation, management or social skills are poorly
taught. Thus there is the need of new academic concepts for teaching
systems engineering skills. This paper presents a project-orientated
training concept to prepare students from different technical degree
programs for systems engineering activities. The training concept has
been initially implemented and applied in the industrial engineering
master program of the University of Applied Sciences Offenburg.
Abstract: Cavitation in cryogenic liquids is widely present in
contemporary science. In the current study, we re-examine a
previously validated acoustic cavitation model which was developed
for a gas bubble in liquid water. Furthermore, simulations of
cryogenic fluids including the thermal effect, the effect of acoustic
pressure amplitude and the frequency of sound field on the bubble
dynamics are presented. A gas bubble (Helium) in liquids Nitrogen,
Oxygen and Hydrogen in an acoustic field at ambient pressure and
low temperature is investigated numerically. The results reveal that
the oscillation of the bubble in liquid Hydrogen fluctuates more than
in liquids Oxygen and Nitrogen. The oscillation of the bubble in
liquids Oxygen and Nitrogen is approximately similar.
Abstract: Laplace transformations have wide applications in
engineering and sciences. All previous studies of modified Laplace
transformations depend on differential equation with initial
conditions. The purpose of our paper is to solve the linear differential
equations (not initial value problem) and then find the general
solution (not particular) via the Laplace transformations without
needed any initial condition. The study involves both types of
differential equations, ordinary and partial.
Abstract: The final step to complete the “Analytical Systems
Engineering Process” is the “Allocated Architecture” in which all
Functional Requirements (FRs) of an engineering system must be
allocated into their corresponding Physical Components (PCs). At
this step, any design for developing the system’s allocated
architecture in which no clear pattern of assigning the exclusive
“responsibility” of each PC for fulfilling the allocated FR(s) can be
found is considered a poor design that may cause difficulties in
determining the specific PC(s) which has (have) failed to satisfy a
given FR successfully. The present study utilizes the Axiomatic
Design method principles to mathematically address this problem and
establishes an “Axiomatic Model” as a solution for reaching good
alternatives for developing the allocated architecture. This study
proposes a “loss Function”, as a quantitative criterion to monetarily
compare non-ideal designs for developing the allocated architecture
and choose the one which imposes relatively lower cost to the
system’s stakeholders. For the case-study, we use the existing design
of U. S. electricity marketing subsystem, based on data provided by
the U.S. Energy Information Administration (EIA). The result for
2012 shows the symptoms of a poor design and ineffectiveness due to
coupling among the FRs of this subsystem.
Abstract: Self-compacting concrete (SCC) developed in Japan
in the late 80s has enabled the construction industry to reduce
demand on the resources, improve the work condition and also
reduce the impact of environment by elimination of the need for
compaction. Fuzzy logic (FL) approaches has recently been used to
model some of the human activities in many areas of civil
engineering applications. Especially from these systems in the model
experimental studies, very good results have been obtained. In the
present study, a model for predicting compressive strength of SCC
containing various proportions of fly ash, as partial replacement of
cement has been developed by using Fuzzy Inference System (FIS).
For the purpose of building this model, a database of experimental
data were gathered from the literature and used for training and
testing the model. The used data as the inputs of fuzzy logic models
are arranged in a format of five parameters that cover the total binder
content, fly ash replacement percentage, water content,
superplasticizer and age of specimens. The training and testing results
in the fuzzy logic model have shown a strong potential for predicting
the compressive strength of SCC containing fly ash in the considered
range.
Abstract: Machining parameters are very important in
determining the surface quality of any material. In the past decade,
some new engineering materials were developed for the
manufacturing industry which created a need to conduct an
investigation on the impact of the said parameters on their surface
roughness. Polyurethane (PU) block is widely used in the automotive
industry to manufacture parts such as checking fixtures that are used
to verify the dimensional accuracy of automotive parts. In this paper,
the design of experiment (DOE) was used to investigate on the effect
of the milling parameters on the PU block. Furthermore, an analysis
of the machined surface chemical composition was done using
scanning electron microscope (SEM). It was found that the surface
roughness of the PU block is severely affected when PU undergoes a
flood machining process instead of a dry condition. In addition the
stepover and the silicon content were found to be the most significant
parameters that influence the surface quality of the PU block.
Abstract: The effect of a 3-dimensional (3D) blade on the turbine
characteristics of Wells turbine for wave energy conversion has been
investigated experimentally by model testing under steady flow
conditions in this study, in order to improve the peak efficiency and
stall characteristics. The aim of use of 3D blade is to prevent flow
separation on the suction surface near the tip. The chord length is
constant with radius and the blade profile changes gradually from the
mean radius to tip. The proposed blade profiles in the study are
NACA0015 from the hub to mean radius and NACA0025 at the tip.
The performances of Wells turbine with 3D blades has been compared
with those of the original Wells turbine, i.e., the turbine with
2-dimensional (2D) blades. As a result, it was concluded that although
the peak efficiency of Wells turbine can be improved by the use of the
proposed 3D blade, its blade does not overcome the weakness of
stalling.
Abstract: Excavation and retaining walls are of challenging
issues in civil engineering. In this study, the behavior of one
important type of supporting systems called Contiguous Bored Pile
(CBP) retaining wall is investigated using a physical model. Besides,
a comparison is made between two modes of free end piles (soft bed)
and fixed end piles (stiff bed). Also a back calculation of effective
length (the real free length of pile) is done by measuring lateral
deflection of piles in different stages of excavation in both
aforementioned cases. Based on observed results, for the fixed end
mode, the effective length to free length ratio (Leff/L0) is equal to
unity in initial stages of excavation and less than 1 in its final stages
in a decreasing manner. While this ratio for free end mode, remains
constant during all stages of excavation and is always less than unity.
Abstract: This paper presents the application of the Discrete
Component Model for heating and evaporation to multi-component
biodiesel fuel droplets in direct injection internal combustion engines.
This model takes into account the effects of temperature gradient,
recirculation and species diffusion inside droplets. A distinctive
feature of the model used in the analysis is that it is based on the
analytical solutions to the temperature and species diffusion
equations inside the droplets. Nineteen types of biodiesel fuels are
considered. It is shown that a simplistic model, based on the
approximation of biodiesel fuel by a single component or ignoring
the diffusion of components of biodiesel fuel, leads to noticeable
errors in predicted droplet evaporation time and time evolution of
droplet surface temperature and radius.
Abstract: Communicating and managing customers’
requirements in software development projects play a vital role in the
software development process. While it is difficult to do so locally, it
is even more difficult to communicate these requirements over
distributed boundaries and to convey them to multiple distribution
customers. This paper discusses the communication of multiple
distribution customers’ requirements in the context of customised
software products. The main purpose is to understand the challenges
of communicating and managing customisation requirements across
distributed boundaries. We propose a model for Communicating
Customisation Requirements of Multi-Clients in a Distributed
Domain (CCRD). Thereafter, we evaluate that model by presenting
the findings of a case study conducted with a company with
customisation projects for 18 distributed customers. Then, we
compare the outputs of the real case process and the outputs of the
CCRD model using simulation methods. Our conjecture is that the
CCRD model can reduce the challenge of communication
requirements over distributed organisational boundaries, and the
delay in decision making and in the entire customisation process
time.
Abstract: Recommendation systems are widely used in
e-commerce applications. The engine of a current recommendation
system recommends items to a particular user based on user
preferences and previous high ratings. Various recommendation
schemes such as collaborative filtering and content-based approaches
are used to build a recommendation system. Most of current
recommendation systems were developed to fit a certain domain such
as books, articles, and movies. We propose1 a hybrid framework
recommendation system to be applied on two dimensional spaces
(User × Item) with a large number of Users and a small number
of Items. Moreover, our proposed framework makes use of both
favorite and non-favorite items of a particular user. The proposed
framework is built upon the integration of association rules mining
and the content-based approach. The results of experiments show
that our proposed framework can provide accurate recommendations
to users.
Abstract: Using cold EGR method with variable venturi and
turbocharger has a very significant effect on reduction of NOX and
grime simultaneously. EGR cooler is one of the most important parts
in the cold EGR circuit. In this paper optimum design of cooler for
working in different percentages of EGR and for determining
optimum temperature of exhausted gases, growth of efficiency,
reduction of weight, dimension, expenditures, sediment and also
optimum performance by using gasoil which has significant amounts
of brimstone are investigated and optimized.