Ingineria Automobilului Society of

Transcription

Ingineria
Automobilului
Romanian
Automobile
Register
Society of
Automotive
Engineers
of Romania
distr ibu ted with au totest mag a zine
No. 20 / september 2011
• Interview with Dr. Ir. Jan Leuridan, LMS International
• Fuel Cell Powertrain Simulation
• Study of Automotive Dynamics and the Acoustic dynamics of the car
• A Better Reliability Modeling in The Cases of Incomplete Tests
• Engine Particle Filters Sytems Research
SIAR is affiliated to
international
federation of
automotive
enGineering
societies
european
automobile
engineers
cooperation
MOTOARE PENTRU AUTOMOBILE ŞI
TRACTOARE FABRICATE ÎN ROMÂNIA
(AUTOMOTIVE AND TRACTOR
ENGINES MADE IN ROMANIA)
Author: Prof. Dr. Eng. Dan ABĂITANCEI
Abstract: This book brings to the fore over 40 types of engines manufactured in Romania in almost 60 years, in international cooperation or national initiatives. This book accomplished a great void in
the literature that reveals a road crossed by an important sector of
Romanian industry, because it draws attention to the younger generation working in this field that walking on a road that has traditions
in Romania. From this book you can find creative and productive
scale activities that took place and they carry generations of people
who have worked and are still working in this area
2011 ALMA Craiova, Publishing, ISBN 978-606-567-089-1
Contact author: +40268 512 243
APLICAŢII DE PROIECTARE ASISTATĂ
ÎN INGINERIA AUTOMOBILELOR
(COMPUTER ASSISTED DESIGN
IN AUTOMOTIVE ENGINEERING)
Autors: Conf. Dr. Ing. Adrian Sorin ROSCA,
Conf. Dr. Ing. Ilie DUMITRU
As. Drd. Ing. Andrei Gheorghe NANU
This book is addressing mainly to students and to those who are involved in the field of automotive engineering. The authors are presenting various subjects related to road vehicles (like engine, transmission
and other sub-systems), using modern software (Catia, Inventor etc).
The book is made up of several examples for each given subject, examples covering a wide range of information that will assist the readers in
their quest to improve the skills and knowledge.
Universitaria Craiova Publishing, 132 pages, ISBN 978-973-742-571-3
Details about the book can be obtained at: [email protected]
Ingineria Automobilului
„INGINERIA AUTOMOBILULUI”
The 5th anniversary
T
he AIAR (Association of
Automotive Engineers of
Romania), founded in 1988 as
part of the CNIT (National Council of
Engineers and Technicians), became
in 1990 SIAR (Society of Automotive
Engineers of Romania), it was the
result of recognizing both national
and
international
professional
prestige of the specialists from
universities, research units and production sector, all involved
in the automotive industry in Romania. It was also decided to
edit a journal to introduce the events of the new company and
to present the most valuable of both Romanian and foreign
researchers acting in the field of automotive engineering. Thus,
in the summer of 1990, with the high professionalism support of
the “Monitorul Oficial”, appeared the first issue of the “Journal
of the Romanian Automotive Engineers” (RIA), whose chief
editor was Dr. Eng. Dumitru Marincaş. The magazine was
published monthly until 2000. Afterward, the appearance of
the magazine ceased because of financial reasons.
On the 1st of October 2006, the new journal “Ingineria
Automobilului” (Automotive Engineering) has been launched
(quarter issue) with the support of the Romanian Automobile
Registry (RAR) and distributed together with the Auto Test
magazine.
During its five years of existence, the journal “Ingineria
Automobilului” has been continuously modernized and
adapted to the field, knowing a series of transformations.
The interviews with prominent personalities at home or abroad
acting in the field of automotive engineering or related to this
area were highly appreciated. The interviews started to be
published with the magazine no. 6 of March 2008. Among the
personalities interviewed it is worth to mention Prof. Gunter
Hohl, General (r), Vice President FISITA and President EAEC;
Mr. Constantin Stroe, general manager of ACAROM and vice
president of Dacia Renault and RTR; Mr. Philippe Prevel and
Mr. Sorin Buse (CEOs Renault Technologie Roumanie); Prof.
Dr. Eng. Nicolae Vasiliu, from the University “Politehnica”
of Bucharest, Department of the Hydraulics and Hydraulic
Machinery; Dr. Peter Pleus, general director of Schaeffler
Romania; Mr. Bernard Gauvin, president of the WP 29, CEEUN; the rectors of universities from Bucharest, Brasov and
Pitesti and more recently, Mr. Andras Siegler, director of the
Directorate Transport of the Directorate General for Research
and Innovation of the European Commission.
New fields which have expanded the journal`s horizon of
information and interest such as “Research in universities”,
“University laboratories”, “Student achievements“ etc. have
been introduced.
The increasing interest in papers and information published by
the “Ingineria Automobilului” determined its managerial team
to increase the number of pages from 16 to 24 (starting from no.
10 of March 2009) and to edit it in two separate formats: one
“printed“ – entirely in Romanian language and one “on-line”
– entirely in English language posted on the website “ingineriaautomobilului.ro”(starting from no. 19 of June 2011).
Celebrating the 5 years of the “Ingineria Automobilului”
journal’s life, often in adverse economic conditions, I
congratulate the editorial team as well as the readers and wish
them long life together!
Mircea Oprean
Summary „Ingineria Automobilului“ No. 20
3 – „INGINERIA AUTOMOBILULUI” The 5th anniversary
5 – Interview with Dr. Ir. Jan Leuridan – Executive Vice-President
& Chief Technical Officer LMS International
7 – Fuel Cell Powertrain Simulation
10 –The Interdependence between the Functional Dynamics
and the Acoustic Dynamics of the Car
12 –A Study Regarding a Better Reliability Modeling
in the Cases of Incomplete Tests
15 –Research on the Construction and Performances
of Particle Filters from the Depolluting Engine Systems
19 –Intermediate Warehouses – Logistics Solution.
A Case Study
23 –Annual Session of Scientific Papers „IMT ORADEA – 2011”
24 –The laboratory for performances certification
of electro-hydraulic amplifiers
University Politehnica of Bucharest
25 – University Research
26 –Challenge KART LOW COST
3
romanian
automobile
register
SOCIETY OF AUTOMOTIVE ENGINEERS OF ROMANIA
President: Prof. Eugen Mihai Negruş
Vice-president: Prof. Cristian Andreescu
Vice-president: Prof. Anghel Chiru
Vice-president: Prof. Ioan Tabacu
General Secretary: Dr. Cornel Armand Vladu
General Manager
Sotir STANCU
Technical Manager
Flavius CÂMPEANU
SCIENTIFIC AND ADVISORY EDITORIAL BOARD
Prof. Dennis Assanis
University of Michigan,
Michigan,
United States of America
Auto Test
Chief Editor
Lorena BUHNICI
Editors
Radu Buhăniţă
Emilia VELCU
Prof. Rodica A. Bărănescu
University of IIlinois at Chicago
College of Engineering
Prof. Nicolae Burnete
Technical University of Cluj-Napoca
Romania
Contact:
Calea Griviţei 391 A,
sector 1, cod poştal 010719,
Bucureşti, România
Tel/Fax: 021/202.70.17
E-mail: [email protected]
Dr. Felice E. Corcione
Engines Institute,
Naples, Italy
Prof. Georges Descombes
Conservatoire National
des Arts et Metiers de Paris,
France
SIAR
Prof. Cedomir Duboka
University of Belgrade
Serbia
Contact
Faculty of Transport
University POLITEHNICA
of Bucharest
Splaiul Independenţei 313
Room JC 005
Cod poştal 060032, sector 6
Bucureşti, România
Tel/Fax: 021/316.96.08
E-mail: [email protected]
Prof. Pedro Esteban
Institute for Applied
Automotive Research
Tarragona, Spain
printing
Eng. Eduard Golovatai-Schmidt
INA-Schaffler KG
Herzogenaurach, Germanz
Prof. Peter Kuchar
University for Applied Sciences,
Konstanz, Germany
Prof. Mircea Oprean
Politehnica University of Bucharest,
Romania
Prof. Nicolae V. Orlandea
Retired Professor, University of Michigan
Ann Arbor, M.I., USA
Prof. Victor Oţăt
Universitatea din Craiova, România
Prof. Pierre Podevin
Conservatoire National
des Arts et Metiers de Paris, France
Prof. Andreas Seeliger
Institute of Mining and Metallurgical
Machine, Engineering,
Aachen, Germany
Prof. Ulrich Spicher
Kalrsuhe University, Karlsruhe,
Germany
Prof. Radu Gaiginschi
Technical University
„Gh. Asachi”of Iaşi, Romania
Prof. Cornel Stan
West Saxon University of
Zwickau, Germany
Prof. Berthold Grünwald
Technical University
of Darmstadt, Germany
Prof. Dinu Taraza
Wayne State University,
colegiul de redacţie
ART GROUP INT SRL
Str. Vulturilor 12-14, sector 3
Bucureşti
Full or partial copying
of text and pictures
can be done only with
Auto Test Magazine approval,
of the Romanian Automobile
Register and of SIAR
Redactor şef
Prof. Mircea OPREAN Universitatea Politehnica Bucureşti
Redactori-şefi adjuncţi
Prof. Gheorghe-Alexandru RADU Universitatea Transilvania Braşov
Prof. Dr. Ing. Ion COPAE Academia Tehnică Militară, Bucureşti
Redactori
Conf. Ştefan TABACU Universitatea din Piteşti
Conf. Adrian SACHELARIE Universitatea Gh. Asachi Iaşi
Conf. Dr. Ing. Ilie Dumitru Universitatea din Craiova
Lector Cristian COLDEA Universitatea Cluj-Napoca
Lector Dr. Ing. Marius BĂŢĂUŞ Universitatea Politehnica Bucureşti
Dr. Ing. Gheorghe DRAGOMIR Universitatea din Oradea
Serie nouă a Revistei Inginerilor de Automobile din România (RIA), 1992-2000
Cod ISSN 1842 - 4074
4
Interview with Dr. Ir. Jan Leuridan
Executive Vice-President & Chief Technical Officer LMS International
Dr. Jan Leuridan is Executive Vice-President and
Chief Technical Officer of LMS International.
Dr. Leuridan received the engineering degree at
the Department of Mechanical Engineering of the
University of Leuven in 1980. He received a M.Sc.
(1981) and Ph.D (1984) from the “Department of
Mechanical & Industrial Engineering of the University
of Cincinnati”. In 1984, he joined LMS International
as R&D Manager, to become Chief Technical Officer
for LMS International. Since 1987, Dr. Leuridan is
member of the Board of Directors of LMS.
At LMS, he has been directing research, technology
and product development programs, aiming at delivering breakthrough solutions for functional performance engineering in mechanical and mechatronic
product development. This includes new solutions for
physical prototyping, virtual prototyping, as well as
innovative, web-centric solutions for technical data
organization and distribution in support engineering
collaboration, enabling the approach of Model Based
System Engineering (MBSE) in mechanical and mechatronic product development.
Ingineria Automobilului: Who is LMS International?
Dr.ir. Jan Leuridan: LMS, the leading partner in test and mechatronic simulation in the automotive, aerospace and other advanced
manufacturing industries, helps customers get better products to
market faster. With a unique combination of mechatronic simulation software, testing systems and engineering services, LMS tunes
into mission critical engineering attributes, ranging from system
dynamics, structural integrity and sound quality to durability, safety
and power consumption. With multi-domain and mechatronic simulation solutions, LMS addresses complex engineering challenges
associated with intelligent system design and model-based systems
engineering. LMS has become the partner of choice for over 5,000
leading discrete manufacturing companies worldwide.
Ingineria Automobilului: How do you see the vehicle of the future?
What is the potential of different clean automotive propulsion technologies for contributing to de-carbonization objective in the short,
medium and long term?
Dr.ir. Jan Leuridan: As polluting fossil-based energy becomes
scarcer and more expensive, governments are taking measures for
a balanced energy mix that combines conventional and renewable
sources, and are making regulations to steer consumer’s behavior.
By 2030, global energy use will be doubled, but CO2-emissions
will have to be reduced by 80% to 95% by 2050. The race to reduce
greenhouse gasses and to achieve greater energy efficiency is offering some of the most challenging engineering opportunities in decades.
Manufacturers and suppliers are developing hybrid-electrical/diesel vehicles, liquid hydrogen-fuelled hybrid propulsion systems, and
electrical navigation drive systems. As a result, there is an increased
demand for power electronics and high-voltage batteries. At the same
time, engineers are downsizing conventional powertrains by ‘supercharging’ smaller engines, and developing advanced fuel efficiency
programs. Design departments are shaping the world’s largest and
smallest vehicles with composite materials to make them lighter. All
of this will greatly contribute to reduce CO2. At the same time this
creates great challenges on automotive development, making the
field of automotive engineering at the same time very interesting. It
has never been a better time to be an automotive engineer!
Ingineria Automobilului: How is LMS transforming its solutions
to support the automotive industry in its’ today challenges?
Dr.ir. Jan Leuridan: Since 1980, LMS has pioneered multi-channel
computer-based testing systems. Innovative software and hardware
applications cover a full set of NVH, structural, acoustic, modal, durability, and rotating machinery applications delivered in a modular
hardware/software platform to support the integrated “LMS Test.
Lab” vision.
5
LMS is the industry’s leading single source provider of best-in-class
hardware and software for high-end testing systems.
LMS Test.Lab became the market reference with more than 5.000
active systems, totaling over 150.000 channels, where extensive user
benchmarks reported 50% performance gains.
By 1995 it was clear that manufacturers had to shorten time-to-market drastically to stay competitive and that physical prototype testing was often one of their critical path bottlenecks. LMS continued
to invest in dramatic, innovative improvements in physical testing
but, at the same time, expanded its vision to include the addition of
virtual simulation … a unique “hybrid” test and simulation solution
that, for the first time, leveraged the best of both the test and simulation worlds.
With a series of acquisitions and innovative partnerships, LMS facilitated the movement to reduce back-end prototype testing, by
frontloading the design process with virtual simulation. In 2000,
LMS introduced the LMS Virtual.Lab platform, which has grown to
simulate many multi-physics, multi-attribute applications.
To accurately simulate multi-domain intelligent system behavior and
predict multi-disciplinary performance long before detailed CAD
geometry is available, LMS acquired Imagine in 2007 and produced
the LMS Imagine.Lab suite for 1D multi-physics simulation.
With the acquisition of Emmeskay in 2010, LMS is again leading a
paradigm shift, this time to evolve its solutions so as to support the
emerging approach of Model Based System Engineering (MBSE).
In complex, mechatronic products, controls and mechanical designs
can no longer proceed independently or in parallel ; they must be
interlocked, MBSE creates the ideal product development architecture to design, calibrate and test controls and controlled systems together in a simulation environment. For the first time, the dynamic
interacting behavior of the growing number of controls and software
can be proven before physical prototypes become available.
Is LMS providing special features/opportunities for Students, BSc,
MSc, doctorate students and for young engineers in terms of using
their passion / hobby for vehicles in research ?
Dr.ir. Jan Leuridan: Since 1980, when LMS started as a spin-off
from the Catholic University of Leuven, Belgium, it has developed
numerous close working relationships with Universities, worldwide. Multiple instruments have been applied for this, including like
in Europe, the participation in collaborative research projects with
Universities in the various EC Framework programs and strategic initiatives aimed at support of Automotive Industry. Examples include
research projects on noise and vibration transmission path analysis
in vehicles (BRITE EURAM BE-4436-90, “DIANA”), on application of smart structures, “adaptronics”, to vehicles (EC 6th FWP,
NMP2-CT-2003-501084), or more recently on warning sounds for
electrical vehicles (I will look up the reference still). Such projects
provide excellent collaboration platforms between academia and
industry for graduate students and researchers. Additionally LMS
has been very supportive to the Research Mobility programs in
Europe, such as the Marie-Curie and Da-Vinci programs, providing
possibilities for graduate students and researchers from universities
all over Europe to spend time at LMS’ R&D centers and participate
to LMS’ research initiatives focused on advancing technology and
methods for automotive engineering. Many of such graduate stu6
dents and researchers have later taken jobs at LMS, and developed
careers through which they could apply their interest and passion
for vehicles to advance LMS’ solutions portfolio for automotive engineering, both test and simulation applications as well as services.
Ingineria Automobilului: How do you see a better communication
between LMS and universities from Romania interested for hiquality research in automotive/multi-engineering domain?
Dr.ir. Jan Leuridan: When LMS established its R&D center in
Romania in 2005, it also took a strong commitment to actively
engage with Romanian Universities in education and research for
automotive engineering. This has materialized in several partnerships, including with the Transylvania University of Brasov and the
University Politehnica of Bucharest. Through such partnerships,
LMS has been providing at favorable conditions its testing systems
and simulation software, to be used as platform for education and
research. Moreover, LMS seeks active collaboration with graduate
students and researchers in research projects focused on automotive
engineering, that are supported by Romanian innovation initiatives,
such as the NVHLMS Project, developed with University Politehnica
of Bucharest and AMCSIT. LMS’ long-standing relationship with
Renault has also facilitated to create opportunities for researchoriented cooperation between LMS, Romanian Universities and
Renault’s Technology Center in Romania. Strongly, we are committed to foster a strong communication and network with Romanian
universities, based on which they can become engaged with LMS
on applied research for automotive engineering, and through which
also LMS establishes its visibility within the Romanian Academic
World as a world-class high-tech company, its growing R&D center
in Romania, with many employment opportunities for professions
focused on test and simulation solutions for automotive engineering.
Ingineria Automobilului: Do you think to affiliate with University
Politehnica of Bucharest and to develop an interesting research
center there?
Dr.ir. Jan Leuridan: In recent years, LMS has been expanding
rapidly its application portfolio for multi-physics, mechatronic
simulation, LMS Imagine.Lab AMESim. This has been driven by
both organic developments, and also acquisitions, including the
French company Imagine (acquired in 2007) and the US company
Emmeskay (acquired in 2010). Imagine had developed a strong relationship with the University Politehnica of Bucharest in the field of
fluid power (hydraulic) simulation, under Professor. Nicolae Vasiliu.
After Imagine became part of LMS, this relationship has further
grown into one where the University Politechnica of Bucharest has
now a leading center of competence for multi-physics and mechatronic simulation, where Imagine.Lab AMESim is extensively used
for education and research. This includes specific expertise for using multi-physics simulation models developed within Imagine.Lab
AMESim as so-called “plant” models to support model based controls engineering, including Real-Time application of such “plant”
models to support Hardware-in-the-Loop (HIL) set-ups. Such
competences are core to LMS’ forward strategy to advance its solutions of mechatronic simulation for automotive engineering, and
are therefore a strong foundation to further expand the partnership
between LMS and the University Politehnica of Bucharest.
Fuel Cell Powertrain Simulation
M. Eng. student Assist. Professor
Mircea Nicolae Marius Valentin
GLAZER
BĂŢĂUŞ
Professor
Ioan Mircea
Oprean
Faculty of Transports,
University POLITEHNICA of Bucharest
This paper presents a theoretical study regarding
fuel cell drive systems. The hydrogen consumption
and the vehicle range are determined using simulation for a medium class passenger car with PEM
(proton exchange membrane) fuel cell as the primary electric energy source. Regenerative braking
and electrical energy management were implemented in the global model in order to have a correct determination of fuel consumption during a standard
drive cycle. The closed loop control for PEM, which
is necessary for maintaining a high efficiency level,
is detailed as well.
Matlab/Simulink programming environment and
the power electronics library SimPowerSystems
were used for modeling and simulation. The model
was validated by comparison of the results with
data given by manufacturer for the simulated passenger car.
Key words: fuel cell, electric drive system, simulation, PEM, PMSM.
INTRODUCTION
The more stringent emissions regulations for
motor vehicles make necessary the research of
new technical solutions for increasing the efficiency of well to wheel energy conversion,
while maintaining or even increasing dynamic
performance and passenger comfort. These requirements lead to reducing green house gas
emissions quantified as CO2 equivalent/100
km. A comparison between different propulsion
systems based on present technology is presented in figure 1 [1].
Electric vehicles have a series of advantages that
lead to the reduction of energy consumption
and gas emissions (especially in urban environment). The main disadvantages concerning the
use of electric energy as the main energy source
are long recharging time and a lack of electric
charging infrastructure, thus limiting mobility of
the electric vehicle. The implementation of fuel
cell represents an efficient solution for improv-
Fig.1. Energy consumption green house gas emissions for different propulsion systems
Fig.2. The main components of the drive train of Honda FCX Clarity (2010 model)
ing the vehicle range and reducing the recharging
time. Also, creation of a hydrogen charging infrastructure can be achieved much more easily due
to fewer stations necessary.
Honda is one of pioneers in applying fuel cell
technology to automobiles, introducing the FCX
model as early as 2002 in Japan and USA [2]. In
2004 the Japanese company developed a new
FCX version fitted with a fuel cell capable of cold
start at -200C. Increasing of the dynamic performance and the capacity to work in a wide range of
climate conditions made the fuel cell power train,
developed on FCX models, competitive with the
internal combustion engine in terms of performance, drivability, reliability and economy.
Dynamic modeling with a high degree of accuracy of the integrated vehicle-power train system is
required for fuel cell power train systems synthesis and fast optimization of the necessary control
and command system. In addition, if it is desired
to follow a drive cycle it is necessary to create a
control loop with a driver model.
DRIVE SYSTEM MODELING
Considering the state of the art in fuel cell vehicle development, Honda FCX Clarity 2010
model, presented in figure 2 [6], was chosen as
7
Fig.3. Global model in Simulink
(1)
(1)
(2)
Fig.4. Electric Drive System
a study case.
The global model is presented in figure 3 and contains the following subsystems:
1. The Driver subsystem is based on a PID controller and has the role of maintaining a small difference between real and reference speed;
2. The Electric Drive System is made up of the
fuel cell, the Li-ion battery, the DC/DC converter, the inverter and the PMSM (permanent
magnet synchronous motor);
3. The Vehicle subsystem is based on a longitudinal dynamic model of the automobile;
4. The H2 Consumption and Range subsystem
calculates the fuel consumption and range during
a drive cycle.
The parameters needed for the vehicle longitudinal dynamics model were adopted or computed
using the vehicle technical specifications presented in [3].
8
The electric drive system model detailed in figure
4 is made up from four main blocks and a safety
module:
1. Electric power management block (Power
Control);
2. Electric system block (Electric System);
3. Electric motor controller block (PDU - Power
Drive Unit);
4. Permanent magnet synchronous motor and
Transmission block (PMSM & Transmission);
5. Safety and electrical measurements module
(Watchdog & Electrical Measurements).
A detailed model available in SimPowerSystems
Library in Simulink [4] was used for the fuel cell.
This is a generic model parameterized to represent most popular types of fuel cell stacks fed with
hydrogen and air. The nominal values of conversion for hydrogen (UfH2) and oxygen (UfO2) are
determined using the following relations:
where:
R - universal gas constant;
T - nominal operating temperature;
N - number of cells;
ifc - generated electric current;
z - number of moving electrons;
F - Faraday constant;
PH2 - absolute supply pressure of hydrogen;
Vlpm(H2) - hydrogen flow rate;
Pair - absolute supply pressure of air;
Vlpm(air) - air flow rate;
x% - percentage of hydrogen in the fuel;
y%- percentage of oxygen in the air.
Based on relations (1) and (2) it can be concluded
that for the fuel cell stack to work at an optimum
efficiency, close to nominal conversion values, a
flow control system is necessary. For the purpose
of solving this problem a control block was realized. It regulates the mass flow of hydrogen and
air in function of the estimated electric current
consumption of the drive system. The hydrogen
mass flow is determined with the formula:
(3)
where:
p - hydrogen pressure;
M - hydrogen molar mass (2.0158814 g/mol).
A dynamic model was used for the electric motor and the controller. It is based on AC6 block
from SimPowerSystems Library [4]. The speed
controller is based on a PI regulator. The output
of this regulator is a torque set point applied to
the vector controller block. These values are used
in the vector controller to generate the reference
sinusoidal current waves needed to command a
three phase IGBT inverter.
The Battery block from SimPowerSystems Li-
brary [4] was implemented for the Li-ion polymer battery. The Battery block implements a generic dynamic model parameterized to represent
most popular types of rechargeable batteries.
The transmission subsystem contains a gear ratio
of 9.44:1 and a constant efficiency of 96%.
RESULTS
The instantaneous hydrogen consumption, as it
can be observed in figure 5, rises to a maximum
of 0.8 kg/h when accelerating and it drops to a
minimum value of 0.05 kg/h while regenerative
braking is in use.
The high fuel cell response time is caused by
Fig.5. Hydrogen consumption and vehicle speed during ECE15 cycle
Fig.6. Vehicle speed and electrical power for fuel cell stack and battery during ECE15 cycle
Fig.7. Fuel cell stack efficiency during ECE15 simulation
the „charge double layer“ phenomenon due to
the build-up of charges at electrode/electrolyte
interface and the dynamics of external equipments (compressor, regulator and loads) [6].
The surplus of electrical energy goes into the
battery, thus maintaining the system in balance.
This phenomenon can be observed in figure 6,
as a high negative current at the battery terminals, while going from positive acceleration to
steady speed.
The fluctuation for effective and maximum
theoretical efficiency of the fuel cell, in ECE15
cycle, can be observed in figure 7. The mean
value for effective efficiency of the fuel cell stack
was 63.88%. This result is very close to the mean
maximum theoretical value which could be obtained in case of an ideal control (64.95%).
CONCLUSIONS
An error of 0.67% was obtained using the block
for acceleration and braking command (DriverPID Controller) in regard to vehicle speed and
NEDC reference speed. The efficiency of the algorithm implemented for the control of hydrogen and air flows was demonstrated.
An estimated hydrogen consumption of 0.832
kg/100 km and a range of 441 km are obtained
for NEDC cycle. An error of 4.3% has resulted
when compared to the range stated by Honda
for NEDC (460 km) [5].
Using only the ECE15 drive cycle a hydrogen
consumption of 0.98 kg/100 km and a range of
386 km are obtained.
BIBLIOGRAPHY:
[1] Peter Froeschle, Electrification of the
Drivetrain – Evolution or Revolution?, 8th
International CTI Symposium & Transmission
Expo, 2009
[2] Souleman Njoya Motapon, A generic fuel
cell model and experimental validation, M. Eng.
Thesis, École de Technologie Superieure,
Universite du Québec, 2008
[3] http://automobiles.honda.com/fcx-clarity/specifications.aspx
[4] Mathworks help toolbox – SymPower
Systems
[5] Toyohei Nakajima, Fuel Cells & Hydrogen
for Sustainable Transport, Industry Update
Meeting, Copenhagen, 30th November 2009
[6] Minoru Matsunaga , Tatsuya Fukushima,
Kuniaki Ojima, Powertrain System of Honda
FCX Clarity Fuel Cell Vehicle, World Electric
Vehicle Journal Vol. 3 - ISSN 2032-6653, 2009
[7] Peter J. Mohr, CODATA Recommended
Values of the Fundamental Physical Constants:
2006,. Rev. Mod. Phys, Vol. 80, 2008, pp.
633–730
9
The Interdependence between the Functional Dynamics
and the Acoustic Dynamics of the Car
Univ. prof. eng. PhD.
Ion COPAE
Military Technical
Academy, Bucharest,
email: ion_copae@
yahoo.com
Eng. Dumitru
RUICU
Armaments Department,
Bucharest, email: ruicu.
[email protected]
ABSTRACT
Experimental research has highlighted the interdependence between functional parameters
frequently used in the study of vehicle dynamics (speed, acceleration and vehicle deceleration,
throttle position, engine speed, fuel consumption
etc.) and the sound level produced during the vehicle’s movement (emitted noise). To this purpose,
the current paper relies on experimental data gathered from vehicle testing sessions, especially those
vehicles that are fitted today with an electronically
controlled engine thus meaning that the existing data is gathered from the onboard computer.
Based on this data, mathematical patterns are established, both discrete and continuous, which
gives the values to the functional parameters that
define vehicle dynamics depending on the sound
level that accompanies their movements. In order
to establish these models, calling on to system
identifying algorithms and to specific procedures
of information theory and extreme values theory.
Also, the paper presents some aspects regarding
the analysis of the acoustic field of vehicles, relying
on algorithms specific to time analysis, frequency
analysis and time-frequency analysis; references
to correlation analysis, cepstral analysis, coherence
analysis, extremal analysis, entropic and informational analysis of the sound level (emitted noise).
The paper highlights some aspects regarding the
synthesis of vehicle’s acoustic field, which allowed
for the establishment of mathematical models both
discrete and continuous which offers values to the
sound level depending on the other functional parameters which define vehicle dynamic behavior.
The moving of cars is accompanied by the appearance of acoustic phenomena, often called noises;
further in this paper it will be used the notion of
acoustic field, which is a generalization [5;6],
hence the concept of acoustic dynamics of vehicle.
This paper aims to address, for the first time in literature, the theoretical and experimental problem
10
a)
b)
Figure 1
of the dynamic interdependence
between functional dynamics and
acoustic dynamics of the car, both
in real time, taking advantage of a
new theoretical treatment and of
the possibility of acquiring data
from transducers and elements
incorporated in the manufacturing execution and taken from the
vehicle’s onboard computer. This
paper uses the instantaneous values of the functional parameters
and noise emitted during the vehicle movement and the mentioned
interdependence will be found in
mathematical models based on
experimental data, applying algorithms to identify
dynamic systems and processes [1;2;4].
The experimental research was conducted with a
Daewoo Tacuma car equipped with fuel injection
engine and allowed data acquiring from transducers and elements incorporated in the manufacturing execution and taken from the vehicle’s onboard
computer. For this purpose was used the SCAN100 tester, the 1 landmark from fig.1a, that was
connected with the vehicle’s onboard computer by
the car diagnostic plug. Also, it was used the laptop
2 from fig.1a on which specialized data acquisition
software was implemented and that was connected
with the microphone 3 from fig.1b using the cable
4, so that the functional parameters and noise measurements flow simultaneous. A special attention
was paid to the positioning of the microphone
for the instantaneous sound recording. Since the
main purpose of this work was to establish the
interdependence between functional dynamics
and acoustic dynamics of the vehicle, both in real
time, the microphone was placed in the engine
compartment, remaining in the same position
during all the experiments. The accuracy of the mi-
Figure 2
crophone placing was confirmed by the analysis of
the acoustic field. Also, it should be noted that the
experimental researches were made after technical
verifications of the car, to avoid other unexpected
noises.��
Obviously,
��
each experimental test has specific features. For instance, fig. 2 shows the experimental values (top graphics) and also the calculated values (bottom graphics) for the acoustic noise
level for two experimental tests, T19 and T20. As
it was expected, there are different variations of the
dynamic series for the two tests. Also, fig.2 shows
(by comparing the top graphic with the bottom
graphic) the interdependence between experimental acoustic field and calculated noise level,
the A points emphasizing the highest values and
the B points emphasizing the lowest values from
the bottom graphics, where it was used the 2-norm
of the ∆h calculation step.Finally, the top graphics
emphasize a variation in the h∈[-1;1] range for
experimental data, that are specific for ”.wav” files
wich on the experimental acoustics is operating.
The graphics from fig. 2 show the pronounced character of variation for experimental acoustic field
and for calculated noise level that accompanies the
car movement. This character suggests that a car’s
Figure 3
Figure 4
Figure 5
acoustic field has a nonlinear and nonstationary
character; from this are arising implications in the
acoustic field analysis (by using some algorithms
for emphasizing the nonlinearity and bispectral
analysis and time-frequency analysis) and in the
acoustic field synthesis (by establishing some nonlinear mathematical models and some mathematical models with variable coefficients). The acoustic field analysis appeals to methods of analysis in
time, frequency and time-frequency analysis; the
frequency analysis (spectral analysis) comprises
the monospectral analysis based on Fourier transform, bispectral analysis and cepstral analysis. Also,
for establishing the linear dependence, it is appealing to bispectral frequency analysis and entropic
and informational analysis of the data; the informational analysis of the data allows determining
the relevant variables, so those variables are adopted like main parameters of mathematical models.
For establishing the values
of the acoustic field outlines’ we appeal to to extremal analysis. For instance,
time-frequency analysis
allows us to determine the
fundamental frequencies,
which concur with the
first formant. Thus, fig.3d
and fig.3c present how the
fundamental frequencies
for T18 test are established
by using the flat spectrogram. Fig.3 chart shows
that fundamental rotation
frequencies are equal to
the νc frequencies of engine crankshaft. This shows the correctness of the
microphone arrangement for instantaneous sound
recording, confirming that the experiments meet
the main requirement imposed, which is to highlight the interdependence of functional dynamics
and acoustic dynamics. The synthesis of the acoustic field, as a complementary analysis, provides
mathematical modeling for the noise level (noise),
which allows the reconstruction / restoration of its
analytical form, tabular or graphical. In this case it
is using the specific acoustic field synthesis algorithms and the algorithms to identify systems and
processes for establishing the mathematical models which have the noise as a result; the mathematical models can be discrete, continuous or extremal
[4; 5].
For instance, Fig.4 presents the establishment of a
generalized linear mathematical model (for all the
40 tests) in continuous (a differential equation)
field, which provides the noise values Z according
to engine speed n and throttle position ξ.
As found in Fig.4, the mathematical model has the
form of a first order differential equation:
(1)
From this expression result related transfer
functions:
- the transfer function related to engine speed with
polynomials in fig.4:
(2)
- the transfer function related to the throttle
position:
(3)
both of them being written in the Laplace
transform argument s. Unlike the previous case,
the mathematical model presented in Figure
5 is continuously offering the car speed values
V depending on the noise level Z, the throttle
position ξ and the engine speed n. Therefore, this
example has three variables as input factor and the
result factor is speed, which defines the vehicle
dynamics. Thus, the example in Fig.4 shows the
relationship between functional dynamics and
acoustic dynamics; however, the example of fig.5
connects acoustic dynamics and vehicle functional
dynamics. The sought mathematical model is a II
order differential equation:
(4)
the modeling error having in this case also an
acceptable value.��
In this case, three transfer functions in continuous field will be established, since
there are three input parameters. For instance, the
transfer function for noise Z is:
(5)
in a similar way also resulting the other two transfer functions. Based on what was presented above
it can be concluded that it is possible to study the
interdependence between functional dynamic and
automotive acoustic dynamics, using functional
parameters commonly used and emitted noise
measured in different places. It should be noted
that, unlike traditional approaches, in this paper
are used the instantaneous values of noise and
other variables that define the functional dynamics
of cars [3; 5].
Mathematical models based on experimental data
highlight the mentioned interdependence and
allow similar approaches on dynamic systems and
functional processes accompanied by acoustic
phenomena.
BIBLIOGRAPHY:
[1] Copae I. Dinamica automobilelor. Teorie şi
experimentări. Editura
��
Academiei Tehnice Militare, Bucureşti, 2003
[2] Copae I., Lespezeanu I., Cazacu C. Dinamica
autovehiculelor. Editura ERICOM, Bucureşti, 2006
[3] Gillespie D. T. Fundamentals of Vehicle Dynamics. SAE Inc., S.U.A, 1992
[4] Ljung, L. From Data to Model: A Guide Tour
of System Identification. Department of Electrical
Engineering, Linkoping University, Sweden, 1995
[5] Ruicu D. Contribuţii la studiul dinamicii automobilelor pe baza câmpului acustic al acestora. Teză
de doctorat, Academia Tehnică Militară, Bucureşti,
2011
[6] Ruicu D., Bivol G., Copae I. Considerations regarding the analysis and synthesis of vehicle acoustic
field. Annual symposium of the Institute of Solid
Mechanics SISOM 2011, Romanian Academy,
Bucharest, 2011
11
A Study Regarding a Better Reliability Modeling
in the Cases of Incomplete Tests
Alexandru BOROIU
Universitatea din Piteşti, Facultatea
Mecanică şi Tehnologie,
Departamentul Autovehicule,
[email protected]
Abstract
For modeling the reliability, there are used specifically designed computing programs, two situations being possible: complete tests and incomplete tests. However, it is found that in the cases
of incomplete tests it is not made distinguish
between the censored type testing (which ends
when a preset number of products of considered batch failed) and the truncated type testing
(which ends at a predetermined time moment).
In the case of the incomplete type testing, there
is not taken into consideration the time interval
between the moment of the last failure and the
moment of the end of the experiment (the case of
truncated type testing). Therefore, based on the
realized study, there is proposed a computing algorithm for modeling the reliability in the case of
the truncated type testing. The obtained theoretical and practical results confirm the utility of the
proposed algorithm. For any other mathematical
model used in the truncated type testing, it will
be built the suitable computer algorithm.
Key words: reliability modeling, computing program, censored tests, truncated tests, Weibull
law.
PROBLEM FORMULATION
Ther are used special designed computing programs to determinate the reliability indicators
for different mathematical models. For example,
ReliaSoft Weibull ++7 [5] is a high-performance
program, which, based on the data obtained by
monitoring a batch of products in the real exploitation or in the framework of special organized
tests, achieve the following:
1 – make the graphs: FS histogram, FS Pie, FS
Timeline (the shape is unique, regardless of
theoretical law that will be used for mathematical
modeling of reliability);
2 – realize experimental distribution modeling
through various theoretical distribution laws:
Weibull-2P, Weibull-3P, Normal, Lognormal,
Exp-1P, Exp-2P, G-Gamma, Gamma, Logistic,
Loglogistic, Gumbel, etc.;
12
3 – make for any models of reliability the graphs
of the following reliability indicators: Probability,
Reliability, Unreliability, Pdf, Failure rate,
Contour (this one only for models Weibull-2P,
Weibull-3P, Normal and Lognormal);
4 – present the graph for each indicator, simultaneously for all the laws, in order to make a com-
parison by viewing them in the same time.
But working with these computing programs, it
was found, however, that these have some limitations in terms of differentiating between different
types of tests. Thus, next there are presented the
following research.
So, it was started from the mileages where it were
Fig. 1. The graph F/S Timeline for the complete test (F = 10, S = 0).
Fig. 2. The graph Probability Weibull-3P for the complete test (F = 10, S = 0).
Table 1. The values for failure times
No
1
2
3
4
5
6
7
8
9
10
Failure time [km]
24791
28427
31175
33871
35338
38033
40102
42913
45218
48203
broken the 10 right transmission shafts of a lot of
cars with the powerplant arranged transversally,
in the framework of a complete test (the test stops
after the failure of all components) – presented in
Table 1.
The experimental data are highlighted in figure 1
(the number of failed elements is F = 10, and the
number of the supervised elements that were not
damaged is S = 0), and the graph Weibull-3P (the
three-parametric model) which shows the values
of the three parameters (β = 3.0129; η = 25157
km; γ = 14417 km) is presented in figure 2.
Using the same values for the proper functioning
times of the 10 transmission shafts, it was imagined an incomplete test in which F = 10 and S =
10, but with different scenarios for the values as-
Fig. 3. The graph F/S Timeline for the censored incomplete test (F = 10, S = 10).
Fig. 4. The graph Probability Weibull-3P for the censored incomplete test (F = 10, S = 10).
signed to the 10 monitored elements which are
not breaks during the experiment:
1 – it is considered censored type test (it ends
with the failure of the tenth element), so for all
the 10 elements that continue to operate, there
are assigned the value of the last recorded time: tS
= 48203 km (figure 3 and figure 4).
2 – it is considered the truncated type test (it not
ends with the failure of the tenth element, but at
a predetermined time, which is higher than the
last recorded time), so for all the 10 elements that
continue to operate, there are assigned a value of
the time at which the test stops: tS = 60000 km.
3 – there are imagined, also, other values for the
truncation times of the experiment: tS. It is found
that for all these different scenarios there are obtained the same values for the Weibull-3P model
parameters, ie, the computing program considers all these different tests as a censored type test
(with the censoring time equal to the time at
which breaks the tenth element).
Continuing the investigations, it is imagined another censored test, in which F = 10, but S = 20
(total, 30 elements are tracked). It appears that
this time it is really obtained different values for
the three Weibull parameters, so the program
has discriminatory power for censorship tests.
Analyzed test data are presented in Table 2.
Continuing the investigations, it is imagined another censored test, in which F = 10, but S = 20
(total, 30 elements are tracked). It appears that
this time it is really obtained different values for
the three Weibull parameters, so the program
has discriminatory power for censorship tests.
Analyzed test data are presented in Table 2.
It concludes that the computing program identifies correctly the complete test and the incomplete tests of censored type, but not the incomplete tests of truncated type. As a result, we intend
to realize a research through which we provide
those theoretical elements necessary to identify
an incomplete test of truncated type and for creating a suitable computing program to model reliability based on this type of tests.
REALIZED RESEARCHES
To find the theoretical elements necessary for
processing the data obtained through incomplete
tests of truncated type, it can be started from the
most visible reliability indicator of reliability which
depends of the type of reliability test, the estimated
value of mean time between failures m [2].
• for complete tests:
(1)
13
eters (O’Connor, 1991):
- γ is the localization parameter or parameter position, an constant that defines the start time of the
variation of reliability function R(t);
- η is the scale parameter, expresses the extension
distribution on the time axis; so, if (t – γ) is equal
with η, R(t) becomes:
Fig. 5. The highlighting of the parameters γ and
η on the graph R(t) in the case of Weibull law.
• for incomplete tests of censored type:
(2)
• for incomplete tests of truncated type:
(3)
where:
- tF is the time corresponding to the failure of the
last element in the censored test;
- ttr is the truncation time of the test.
In the particular case of modeling by law Weibull3P, the mean time between failures value m is
depending of the all 3 Weibull parameters:
(4)
where Γ represents the Euler function of first rank
(Gamma type), defined through the analytical
relation:
(5)
Since the analytic relation of this function is quite
complicated, in reliability studies is more easily
to work with the function values calculated and
listed in tables (Andreescu, 1996).
The indicator m is in relation to all the three
Weibull parameters, so we are not dealing with a
bi-univocal relationship, deterministic, so that
will be performed an analysis to decide which of
the three indicators is most appropriate to be corrected depending on the value of m , and thus
depending on the type of test.
For this, we must define the three Weibull param-
β
R ( t ) = e −1 = e −1 = 0.368 ,
(6)
ie, scale parameter represents the time, measured
from the moment γ = 0, at which 63,2% of the
elements can be failed. Therefore, this parameter
expresses a characteristic operating time.
- β is the shape parameter, is dimensionless and
represents the parameter that determines the
shape and curves of variation for the reliability
indicators.
The parameters γ and η are expressed in time units
and can be graphically highlighted (figure 5).
As the previously revealed problem express that
the program does not offer the possibility of extending the distribution on the time scale according to the value of truncation time (larger than
the censoring time), it follows that the most suitable to be put in a deterministic relationship with
the mean time between failures m is precisely
the scale parameter η. For this, there will be processed the analytical relations for the mean in the
case of the two types of tests – the censored test
(for which the program calculates the parameters
Weibull, including ηcens) and the truncated test
(which is intended to determine the parameter
ηtrun):
(7)
(8)
It results the inegality:
, (9)
By reducing the inequalities (2) and (3) to equalities there is obtained concrete and satisfactory
values for the means, so based on the relation (9)
it can be effectively realized the calculation for
parameter ηtrun.
Table 2. Experimental data and results obtained in the framework of reliability tests.
No.
Test Type
F
S
F+S
The values of the Weibull 3-P model parameters
1
completed
10
0
10
β = 3,0129; η = 25.157 km; γ = 14.417 km.
2
censored
10
10
20
β = 1,6984; η = 35.616 km; γ = 19.871 km.
3
truncated
10
10
20
identical with row 2
4
censored
10
20
30
β= 1,5497; η= 49.639 km; γ= 20.429 km.
14
(10)
Thus, in the case of truncated test from the position 3 in Table 2, we obtain the relation (10).
a value according to what is expected for the truncated test: a more extended theoretical distribution on the time axis, compared with the case of
censored test.
Therefore, the Weibull model which will be used
for the truncated test from the position 3 in Table
2 will have the parameters: β = 1.6984; η = 44897
km; γ = 19871 km.
Conclusions
Based on the realized researches, it can be build
a computing program for the case of incomplete
tests of truncated type in the case of Weibull
model, by using the additional relationship (10).
In the cases of other mathematical models (including the models with one parameter, even
there is no issue of the parameter choice that will
be corrected) – [4], a similar analysis is required
to create the computing program that will complement the complex software dedicated to reliability study.
Bibliography:
[1] Andreescu, C., a.o. (1996), Aplicaţii numerice la
studiul fiabilităţii automobilelor, ISBN 973-958560-4, Ed. Magie, Bucureşti
[2] Cordoş, N., Filip, N. (2000), – Fiabilitatea
autovehiculelor, ISBN 973-99779-4-4, Ed. Todesco,
Cluj-Napoca
[3] O’Connor, P. (1991), Practical Reliability
Engineering, ISBN 0-471-92696-5, Ed. John
Wiley&Sons, New York
[4] *** (1987), Automotive Electronics Reliability
Handbook, SAE, ISBN 0-8988-009-5, Warrendale
[5] *** www.reliasoft.com
Research on the Construction and Performances
of Particle Filters from the Depolluting Engine Systems
Prof. univ. dr. ing. Florian IVAN
Catedra Automobile
Facultatea de Mecanică şi Tehnologie
University of Piteşti
[email protected]
[email protected]
University of
Piteşti
drd. ing.
Daniel LIŢĂ
drd. ing.
Andrei BUŞOI
Table 1 EURO standards evolution
Pollutants
Norme
Euro 3
(2000/2001)
Euro 4
(2005/2006)
CO [g/km]
HC
[g/km]
Diesel
ID/
IDI
Gas
Gas
0,64
2,3
0,5
1
HC+NOx
[g/km]
NOx [g/km]
Diesel
Diesel
ID/IDI
ID/IDI
0,2
0,56
0,1
0,3
Particles [g/km]
Gas
Diesel
ID/
IDI
Gas
0,5
0,15
0,05
-
0,25
0,08
0,025
-
ID
Euro 5a
0,005
0,06
0,005
0,23
0,18
0,1
0,5
1
(2009/2011)
Abstract
The paper presents an analysis of the construcEuro 5b
0,5
1
0,1
0,23
0,18
0,06
0,0045
0,0045
(2011/2014)
tive solutions of diesel particle filters (DPF)
which make up a depolluting system specific
Euro 6b
0,5
1
0,1
0,17
0,08
0,06
0,0045
0,0045
to middle class cars. There are also mentions
(2014/2016)
regarding the formation of mechanic particles
(MP), from the exhaust gases, highlighting the DI – direct injection IDI – indirect injection
necessity to reduce their concentration and the
specific ways to fulfill this objective. An analysis
of the DPF regeneration methods is also presented and of the implementation solutions on
the car. The paper also presents the results of the
research concerning the pressure drops value
Figure 1. The escapes absorbed by
Figure 2. Structure of the mechanic
limits in the case of a new DPF and another one
the respiratory tract
particle
subjected to repeated regenerations.
The need to post-treat the
exhaust gases of car engines
The fitting of the cars equipped with compression ignition engines (c.i.e) and spark ignition
engines (s.i.e) with direct fuel injection within
EURO 5 and EURO 6 standards supposes special depollution measures by using the posttreatment exhaust gases systems. The strict limits of these standards are presented in table 1. In
this context experience has shown that the parFigure 3. The mechanic particles formation mechanism
ticle filter (DPF -diesel particle filter) is an indispensable element within the depollution system
structure. Therefore, extended researches are
taking place both as to the mechanism of the
particle formation as well as to the constructive
optimization of the PAF. These researches are
also connected to way of regeneration of these
a) a)Ceramic monolith DPF b) b) Metallic fibers DPF
filters and the implementation architecture of
Figure 4. Longitudinal section of a DPF
the DPF on a car.
15
Figure 6. Cerina adding
PAF
Figure 5. The pressure drop curve
through the DPF
Figure 7.Injection ways
Figure 8. Fuel injection technologies
Constructive and working
DPF data
The particle filter is a filtration system used to
retain fine particles, having a cancerigenic effect,
contained in the exhaust gases. These soot particles are essentially made up of carbon and they
have typical dimensions varying between 10 nm
and 1 μm. Finer particles (nanoparticles) cannot
be fully retained by the constructive solutions of
the FAP.
Experimental studies have shown that the hidrocarbs at high temperatures (more than 1500
°C) and with little oxygen (rich mixture, the
excess air coefficient, λ<0,6), conditions met
inside the fuel flow, simultaneously taking place
the dehydrogenation phenomenon. Therefore,
the carbon gathers in six-angled structures
(mineral carbon) and it forms layers which give
birth to spheres having a diameter of 400 Ǻ. The
spheres are known as turbostratic structures and
after they reach such dimensions they become
very unstable and begin to gather in irregular
structures and shapes, most of them measuring between 0.01 and 0.1 µm. These structures
16
1- engine; 2- combustion chamber; 3- common type injection; 4- fuel tank; 5- injector +
regulator; 6- low pressure pump; 7- additive; 8- engine computer; 9- gauges; 10- resonator;
11- pre-catalyst case; 12- PAF; 13- post combustion; 14- regeneration; 15- filtered gases.
mostly made up of carbon, contain almost 1%
hydrogen and are known as soot. The soot particles that reach the exhaust system meet unburnt
hydrocarbons due to the heavy escapes of fuel
or oil. When temperatures goes below 500°C,
these heavy hydrocarbons firm on the surface
of the soot particles giving birth to mechanic
particles.
Mechanic particles represent a real threat to
human health. Their effects on the respiratory
system are well known, as well as their cancerigenic ones when inspired. If nowadays the actual standards impose limits regarding the mass
of the particles, in the future these standards will
have to mention also their dimensions, as well as
their numbers, because it is well known that the
smallest MP are also the most dangerous. Figure
1 shows the relation between absorbed particle
percentage by the respiratory system and their
dimensions. One can notice that the highest
absorption percentage belongs to 0.1 MP (the
circles area in figure 1).
The formation mechanism of these particles
is rendered schematically in figure 3, and their
structure in figure 2.
The composition of a MP depends on the perfecting of the burning process (the organized
movement in the combustion chamber, overfeeding, the air/fuel relation), the Diesel oil
quality (sulphur content, cetane number), the
post treatment temperatures of the system catalyst case- particle filter.
When making the particle filters (DPF) one
uses porous ceramic materials such as silicon
carbide or cordierite, and more recently metallic fibers.
Ceramic monoliths are permeable to gas and
they have a porosity (the total volume of the
pores as related to the total volume of the body)
of 52% (less than 9-10 μm). Generally, in the
case of a 52% porosity, the monoliths have the
following densities:
For the cordierite ceramic: 490g/l;
For the silicon carbide :720g/l.
The major difference between the two types of
monoliths is made by the melting temperature
of almost 1355°C in the case of the ceramic
cordierite, and in the case of the silicon carbide
this one exceeds 2000°C. Figure 4a renders
schematically the interior structure of a monolith used to make the DPF.
The metallic fiber particle filter is made up of a
packet of porous, unfretted metallic sheets, rendered schematically in figure 4b.
For a good functioning these filters require the
use of fuels with a sulpher concentration of less
than 500 ppm. On these conditions the DPF
manages to retain over 90% of the released mechanic particles. Unlike ceramic monoliths, the
metallic fiber filters are not brittle and they have
the melting temperature characteristic to nickel
or titanium, constituent metals. A special problem is represented by the DPF regeneration.
Regeneration supposes making it able to retain
particles and to ensure their exhaust. In order to
have an effective regeneration two basic conditions must be fulfilled:
• the initial temperature when entering the DPF
should be between 550°C and 650°C;
• the O2 percentage of the gas that crosses the
filter should be between 5% and 10%.
In a first phase the filter retains the particles,
and when a certain degree of loading is reached
regeneration starts. This phenomenon takes 20
minutes at every 300-500 km, depending on the
harshness of the working conditions.
The efficiency of a particle filter, as well as its
good functioning is established after specific
experimental investigations. Therefore, the authors have highlighted, comparatively, the pressure drops curves in a reference DPF and a new
one, subjected to repeated regenerations /3/,
/4/. One had in view that in both cases – new
PAF and regenerated DPF – the curves be with-
Figure 9. DPF under the floor
Figure 10. DPF under turbo
Figure 11. NOx -TRAP + PAF + exhaust injector
in the admitted limits by curves 1 and 2 (figure
5). The inferior and superior limit curves are established on some similar vehicles ensuring the
fitting within the EURO 5 standards. The reference pressure drop curve represents the middle
area of the range. One has in view that DPF have
a pressure drop as close as the reference curve 3.
One notices that after the regeneration the pressure drop curve through the DPF undergoes a
change from curve 4 to curve 5. This applies to
all new particle filters, which need a stabilization
period to obtain the expected results.
The analysis of the DPF
regeneration methods
Two basic conditions must be fulfilled in order to
have an efficient regeneration: The initial temperature when entering the DPF should be between
550°C and 650 °C and the oxygen gas percentage
crossing the filter between 5% and 10%.
Generally, two ways of regenerating the DPF are
known, namely:
- Passive (natural) regeneration, occurring when
the running engine has high rotation and charge
(regeneration is the consequence of high temperatures reached by the gases in the exhaust
section);
- Active regeneration, which supposes either fuel
injection in the DPF upstream or late injection
(post injection) in the combustion chamber,
electronically controlled. Post injection adjusts
with the temperature increase given by the catalytic reactions of oxidation and with the oxygen
quantity controlled with the help of a shutter.
The main problems occurring when implementing the DPF on a vehicle are related to the old
DPF recycling, limited lifetime and the constraints related to the vehicle architecture.
There are several active regeneration methods:
a) Regeneration by Diesel oil cerina (Ce) addition
Experience has shown that by Diesel oil cerina
addition (only during the regeneration period),
the particles formed and collected by the DPF
can be oxidized by burning at a lower temperature. The solution has been developed on some
Peugeot - Citroën engines, figure 6. Though, it
has a series of disadvantages: high recycling and
maintenance cost, limited lifetime, implementing difficulties.
b) Active regeneration with cylinder post injection
Figure 7 presents schematically the differences
between the standard injection way and the
regeneration one. In the green circled area the
main injection and the post injection are meant
to make up couple.
The red area, late post injection is used to increase the DPF entering temperature due to the
exothermic reaction within the catalyst case.
Experience has shown that late post injection
has a strong impact on oil dilution, with unwanted effects concerning the HC concentration.
c) Late post injection active regeneration upstream the DPF
Two technologies of injection are used upstream
the particle filter, presented in figure 8.
In figure 8, variant a, one injects the fuel upstream the catalyst with the help of an injector,
and in variant b, the Diesel oil is vaporized with
the help of a preheated spark plug, resembling
a tube with a wasteful resistance. This regeneration method is costly enough, and the injector
or the spark plug have to work under severe
thermal and chemical conditions, which leads
to low reliability.
d) Mixed active regeneration (with post injection upstream the DPF and cylinder post injection)
This method consists in combining the late post
injection with the fuel injection in the exhaust
section. Thus, one tries to reduce the oil dilution effect due to the increasing release burning
and the supplementing of the thermal necessary for an optimal regeneration with the help
of the exhaust injector. The major disadvantage
of this method consists in introducing a new actor which has to be controlled and introduced in
the injection computer system, as well as a fuel
increase consumption.
Due to making technology and used materials,
metallic fiber filters can be regenerated by the
same methods as the particle filters made up
of ceramic monoliths. Moreover, these have as
17
advantage the regeneration possibility through
electric heating of the fibers.
The analysis of the DPF implementation solutions within
the exhaust gases system in the
internal burning engines
Regarding the chosen regeneration way, a certain architecture solution of the post treatment
exhaust gases system has to be implemented
on the car. The main implementation solutions
on the car are:
a) DPF placed under the floor downstream
DOC
In the case of this solution the necessary regeneration DPF temperature is obtained by using
the cylinder post injection. Due to the functioning of the compression burning engines
with poor mixtures, the catalyst case C1, called
DOC–Diesel Oxidation Catalyst fulfills two main
functions: on the one hand it ensures the classic
depollution (it changes by oxidation CO into
CO2 and HC into H2O and CO2), and on the
other hand it ensures the thermal necessary for
the regeneration (due to exothermal oxidation
reactions within the catalyst case). On the other
hand, due to the great distance between the vortex wheel and the DPF, the second catalyst case,
C2, should bring back the gas temperature to regeneration values. Regeneration control is done
with the help of the injection computer based on
the information received from the temperature
and pressure gauges. The closed buckle control
system ensures the DPF entering temperature
varying between 550 - 650°C to start regeneration and it limits the maximum temperature at
670°C to avoid the DPF destruction.
In figure 9 one used the following abbreviations:
TC – measuring temperature gauge in the catalyst
case; Sλ – lambda well; TDPF – temperature measuring gauge in the PAF; PPAF- pressure gauge before and after the DPF.
The information received from these gauges
are used to control and manage regeneration,
as well as to verify the working state of the post
treatment system.
This solution has as advantages the DOC quick
kicking-off (130 – 150°C). As to the important
disadvantages one mentions: the necessary regeneration temperature is reached difficultly
(which makes regeneration to be difficult and
the increase of the oil dilution), a high cost due
to using two catalyst cases.
The solution can be met on applications of Fiat,
Saab and Opel constructors.
18
Figure 12. The NOX-TRAP
functioning phases
b) DPF placed under the overfeeding aggregate
This solution has been accepted by Mercedes
and BMW and has as advantages minimal thermal losses between the overfeeding aggregate
and the catalyst case. Therefore, regeneration is
easy. It has the disadvantage of setting difficulties.
c) DPF placed after NOx -TRAP + exhaust
injector
The solution used by Renault and Toyota is
presented in figure 11. In order to reduce the
dilution effect caused by the damage of the post
injection burning, this solution proposes adding
fuel injection in the exhaust section. A reduced
post injection is also maintained so that the
exhaust gases temperature remain at a value to
allow vaporization of the injected Diesel oil in
the exhaust section. The depollution chain also
comprises a catalyst case stocking NOx, called
NOX-TRAP. This fulfills the functions of a DOC
ensuring the regeneration temperature and,
moreover, fulfilling the NOx reduction function. Its construction resembles classic catalyst
cases, the major difference being made by the
fact that the active material contains besides
the noble metals used (platinum, rhodium) also
barium or zirconium. The NOX-TRAP functioning supposes two phases:
-the absorption phase, takes place during the
normal functioning engine period; during this
phase, after the platinum reaction NO changes
into NO2, and the barium oxide connects the
NO2 molecules, resulting a compound, barium
nitrate, Ba (NO3)2, retained on the monolith
surface covered with active material.
-the reduction phase, is characterized by an engine
functioning close to λ=1, that is to a minimal air
quantity in order to have a complete Diesel oil
burning. At the end of this phase the release as
N2 occurs into the atmosphere. The chemical
element responsible with NOX reduction and
their release is rhodium.
The two functioning phases are shown in figure 12.
This solution offers as advantage a good vaporization of the Diesel oil in the exhaust section. It has
as disadvantage the fact that a regeneration at repeated periods is required (around 100 km), and
the Diesel oil injection into the exhaust section
leads to a fuel increase; on the whole, a high cost.
5. Conclusions
The fitting within the strict pollution standards
of EURO 5 and EURO 6 (c.i.e. and s.i.e. with
direct injection) requires that cars be equipped
with very complex depollution systems. Within
these systems the particle filter (PAF) is indispensable. The depollution performances are
connected on the one hand to the way in which
the PAF works with the other elements in the
depollution system structure (DOC, NOXTRAP, EGR, etc.) and on the other hand to its
placement way along the exhaust section. In this
context the constructive solutions for a PAF impose extended research which have in view the
minimization of the pressure drops (counter
pressure) and the regeneration way. The optimal
solution has to be selected taking into account
the production and maintenance costs.
Bibliography:
[1] Plint, J., Martyr, T., Engine testing, Theory &
Practice, SAE, Casebound, 2007.
[2] Khair, M., Majewski, A., Diesel emissions
and their control, SAE, Hardbound,2006
[3] Busoi, A., Ivan Fl., Dumitru, C., Experi
mental research concerning the validation of a PAF
constructive variant for a C.I.E. meant for light
drive, Scientific buletin, Faculty of Mechanics
and Technology Automotive, 2010.
[4] Busoi, A., Ivan Fl., Dumitru, C. Research on
the exhaust gases backpressure effect regarding the
filling and the dynamic performances of the spark
ignition engines, CONAT 2010 – Braşov.
[5] www.dcl-inc.com
[6] www.avl.com
Intermediate Warehouses – Logistics Solution.
A Case Study
Cristina MANEA
Catholic University of Louvain,
Belgia
KEYWORDS –logistics, distribution network,
logistic platform, warehouses location, cost optimization
ABSTRACT
The main focus of the paper is the use of regional warehouses in the architecture of distribution
networks. It proposes an algorithm for optimal
warehouses location and it discusses in what
conditions it is a better logistic solution than
direct distribution.
In the first section, the paper reviews the notion
of regional warehouses, the role they play in a
distribution network and the structure of distribution architectures using them. The second
section tackles the problem of optimal location
for the intermediate warehouses by proposing
a way of modeling this logistic problem and an
algorithm to solve it.
The operational nature of the findings is tested
in the following section of the paper in an empirical study on a Romanian food company with
a country wide distribution network, a Just in
Time organization of flows and whose production plant is located in the suburbs of Bucharest.
Polyvalent factory
Regional
platform
Regional
platform
Regional
platform
Distribution to retailers with own
company’s vehicles
Fig 1. Exclusively using intermediate
platforms distribution
The algorithm proposed in the
second section helps finding
the optimal location for the intermediate warehouses in each
distribution area: Muntenia,
Transilvania,
Moldovia,
Dobrogea and South Region
(with Bucharest). The conclusions outline the benefits of
using regional platforms in the
case of this company instead
of direct distribution.
Fig.2: Transportation cost components from the production
The paper concludes explainplant to the retailers
ing in what conditions using
intermediate platforms is better that direct distribution.
agement is highly integrated and it has as one
INTRODUCTION
of primary priorities the reduction of stocks.
Romanian companies face today the new logis- Therefore, this system demands a rapid flow of
tics challenges in order to cope with interna- goods in order to reduce as much as possible the
tional competition. This study discusses a logis- level of stocks and thus the classical function of
tic solution concerning distribution, and more storage of the logistic platforms (which were inispecifically transport, which has been more and tially warehouses) became far more complex.
more implemented recently, namely the use of There are today millions of logistic platforms
regional distribution warehouses.
all over the world which are passed in transit
INTERMEDIATE WAREHOUSES
by merchandise going to different locations,
SOLUTION
switching means of transport or even getting asIn Romania road transport is the most common- sembled from pieces coming from several localy used means of transport for merchandise. The tions.
classical choice for transporting goods is to di- In this study we are going to narrow our analysis
rectly delivery them from the production plant to the storage function of the intermediate loto each final retailer. An alternative option is the gistic platforms. Therefore, from now on we are
use of intermediate warehouses (fig1). From a going to refer to intermediate logistic platforms
transportation point of view, they facilitate the as regional warehouses.
grouped transport of the merchandise going to One of the key issues to be solved when it comes
different locations up to a place near these loca- to distribution architectures using regional
tions by big capacity trucks, and thus at a low warehouses is the choice of their optimal locaunit1 price per kilometer, which may signifi- tion. There are several strategic objectives to
cantly reduce the transportation cost. From the be taken into consideration when tackling this
regional platform to the retailers the transport issue such as minimization of costs and of duis operated by small capacity trucks which may ration, proximity to key clients, flexibility and
offer more flexibility.
security of transport.
Nowadays, more and more companies choose Today there are various specific software which
to manage their production flows in Just in Time. can indicate the right location depending on the
In this kind of systems the production man- parameters taken into consideration ranging
from specialized ones to more integrated ones
1. By „unit” we mean unit of transport which is such as APS (Advanced Planning System) or
the standard box of 1m3 (with the standard dimenERP (Enterprise Resource Planning).
sions 0,850m x 1,240m x 0,970m) placed on a pallet. From now on we will call it „eurobox”. The The aim of the next section is to tackle this issue of warehouse location by proposing a way of
goods are wrapped in this type of boxes.
19
modeling this logistic problem and an algorithm
City 1
City 2
City 3
City 4
to solve it.
City
1
The cities where the retailers of the
OPTIMAL WAREHOUSE LOCATION
sector can be found. The proper loHYPOTHESIS
City 2
cation of the intermediate warehouse
On suppose that the whole production is done
City 3
will be chosen among them.
in a single factory from which the goods have to
City 4
be transported to several retailers.
TOTAL
The retailers can be found in different sectors
(sector can mean a country, a city or a geoFig.3 Spreadsheet design
graphic region where there is a concentration of
demand).
The algorithm is run using history data of sales
by supposing that the variation of future sales
respects the same repartition between retailers
within a sector.
OBJECTIVE
Find the proper location of the regional (or intermediate) warehouse in each sector in order
to optimize the distribution flows. Optimizing
the distribution flows can be understood here as
minimizing the cost of transport. The same algorithm will be run separately for each sector.
GENERAL ALGORITHM
Fig.A
The cost of transportation that we aim to minimize is the sum of:
(Nb. of necessary Big Trucks for total quantity of is minimal.
a) the cost of transportation of the total mer- merchandise of the sector) X (Cost of transport per In order to facilitate the analysis, spreadsheets
chandise of the sector from the production plant
km Big Truck)
(Excel) will be used. We are going to propose
to the regional warehouse and
The cost of transportation from the intermedi- an original design for the tables that will ease
b) the cost of transportation of the merchan- ate warehouse to each retailer of the sector it is manipulation of data and will facilitate visualidise from the intermediate warehouse to each the sum of costs of transportation of the quan- zation of results.
retailer from the sector
tity needed by each retailer from the regional We will start by building a square table like the
The transportation to the regional warehouse is warehouse. Each of these costs depend as well one in figure3 with the cities (where the retailers
operated by big capacity trucks, whereas the one on the distance between the warehouse and the of the region can be found) as header column
from the regional warehouses to each retailer by retailer, on the number of small trucks4 needed and header row.
small capacity trucks.
to transport the merchandise needed by that Next, for each column, we will introduce the
Total Cost of Transportation = Cost (Production very retailer and on the cost per kilometer for distances (fig.4) between each two cities. For
plant  Intermediate Warehouse) + Cost
a small truck.
instance, for the first column, where City1 and
Cost of Transportation=
(Intermediate Warehouse  Each Retailer)
City2 (from the second row) meets we introThe cost of transportation from the production
duce the distance [km] between them.
[
(
NbKmInterm
e
d
.
Warehouse
→
R
e
tailer
)
k ]
∑
i • NbSmallTrucks • Cost / KmSmallTruc
plant to the intermediate
warehouse
is
a
funcOn
the
principle
diagonal
where
City
meets
i
∑ [( NbKmIntermed .Warehouse → Re taileri ) • NbSmallTrucks • Cost / KmSmallTruck ]
tion of the number of kilometers between them,
Cityi, we will introduce instead of zero (which
Intermed.Warehouse  Retaileri
of the number of big trucks2 needed to transport
would be normally the distance between Cityi
the total quantity of merchandise of the sector We can now write the minimization problem and Cityi) the distance between the production
and of the cost per kilometer for a big truck.
(equation 1) we have to solve as in Figure A.
site and Cityi.
Cost of Transportation Prod.Plant  Intermed. We can now find the city (among those where Now, for each column, adding the number of
Warehouse = (Nb. km3 Prod.Plant  Intermed. the retailers can be found) where, by locating kilometers (in an additional row) we will obtain
Warehouse) X
the regional warehouse, the cost of transport the total distance that would have to be traveled
would be minimal. Intuitively, the proper loca- should the regional platform been located in the
tion will be the right compromise between dis- city staying in the column header. This can be
easily understood (have a look to fig2 while read2. By „big truck” we mean a truck with a high load tances and quantities.
capacity (often between 80 and 120 m3).
Finding the city that by locating here the region- ing the explanation). For instance, for the first col3. Some abbreviations will be used in this section al platform we minimize the transportation cost umn (fig.4) with the header “City”1 we analyze
such as Nb. for «Number», Km for “Kilometer”,
means finding the city for which the above sum the case in which City one is the location for the
Intermed. for “Intermediate”, Prod. for “Production”, Ret. for “Retailer”, Transp. for “Transpor- 4. By „small truck” we mean a truck with a low regional warehouse: in the first cell (which belongs to the principal diagonal) we have the distation”
load capacity (often less than 40 m3)
20
Total distance of transport [km] if the regional plateforme were placed in City 1

City 1
City 2
City 1
Nb Km Prod.plant -> City 1
City 2
Nb Km City 1->2
City 3
Nb Km City 1->3
City 4
Nb Km City 1->4
TOTAL
=Total nb Km production plant-> retailers
City 3
City 4
Fig.4 Introducing the variable of distance between destinations
City 1
Cost City 1 [lei]
City 1
NbKm Prod.
Plant-> City 1
NbKm Prod.Plant -> City 1 X
Nb Big Trucks needed to transport the entire quantity of goods
demanded in the sector
X Cost/Km BigTruck
City 2
Nb Km City 1-> City 2
Nb Km City 1- City 2 x
Nb Small Trucks needed to transport the quantity needed in City 2
X Cost /Km Small Truck
City 3
Nb Km City 1- City 3 X
City 4
Nb Km City 1- City 4 X
TOTAL
Nb Total Km
= Total cost of transport if the
regional platforme were placed
in City 1
City 2
City 3
City 4
Fig. 5 Computation of annual cost of transport for each possibility
of regional platform location
tance from the production plant to City 1 (the
distance between the production site and the
purported regional platform) and then in the
second one the distance between city 1 and city
2 (i.e between the purported regional platform
and the retailers in city 2) and then between city
1 and 3 and so on. By adding these distances, we
obtain the total number of kilometers that have
to be traveled in the sector should the regional
warehouse be located in City 1. Then, we make
the same calculation for each column (i.e. we
calculate the total distance in each possible case
of regional warehouse location). In the end, by
comparing the total number of kilometers for
each case, we can already see which the location
of the platform is which minimizes the total distance that has to be traveled.
As we can see, the analysis is done on column,
that is, in each column we make a simulation by
supposing the regional platform is located in the
city which stays in the header of the column. The
comparison is made below each column and the
result can be easily visualized.
However, as we have already shown (fig.1), the
cost of transportation depends as well on the
quantities that have to be transported. By dividing the quantities by the specific capacity of the
truck that is going to carry them (i.e. big capacity
trucks up to the regional warehouse, and smaller
ones from the warehouse up to local retailers) we
can get the number of trucks needed. According
to the sum to be minimized presented in the
beginning of this section (equation 1 and figure
1), we can calculate the cost of transportation as
showed in figure 5 by multiplying the number
of kilometers with the number of trucks and the
appropriate cost by kilometer.
In order to do that, we are going to insert near
each column in the table we used for calculating the distances (fig.4), an additional column
where we are now going to calculate not the
costs of transport. It has to be kept in mind, on
one hand, that the analysis is made by column
(the same logic we used to compute the distances) and, on the other hand, that in the cells
near the principal diagonal the cost of transportation from the production plant to the city in
column/row header has to be introduced (there
is an example in figure 6 for City 1).
It is obvious that the cost per kilometer for a big
and a small truck have to be previously calculated as they enter the analysis as constants. As
for the number of trucks needed it is advisable
to previously build a table as the one in figure 6
and to link it to the table in figure5.
Name of the city = Title (Column Min Total Cost)
As we can see, the algorithm is easy to implement
and its structure offers as well the possibility of
computing the cost of distribution. By having
the cost of distribution for an optimal distribution architecture with regional warehouses,
a comparison with the cost of direct distribution can be done and the choice concerning the
proper distribution network can be made.
THE CASE OF A ROMANIAN
COMPANY WITH A COUNTRY-WIDE
DISTRIBUTION NETWORK
S* Foods5 is a Romanian company which develops a production activity in the food branch. Its
production plant is situated in Bucharest and it
distributes its products all over Romania.
The company has an internalized distribution
function and its distribution network is divided
in five sectors (demand concentration areas):
Banat, Transylvania, Moldavia, Dobrogea and
South Region with Bucharest.
At present, the company has an intermediateplatform distribution network with a warehouse
in every sector, except for the South Region
(with Bucharest) where it went for a direct
distribution. The actual platforms can be find
in Timisoara (for Banat region), in Cluj (pour
Transylvania region), in Bacau (for Moldavia region) and in Constanta (for Dobrogea region).
5. The real name of the company as well as the
brands of the products are not revealed because of
issues of confidentiality. However, the data used
for the analysis is real, coming from the accounting management records of the company.
21
Local warehouse
Quantity to be transported to each
destination [number of standard
boxes placed on pallets]
Nb de camions nécessaires
par destination
City 1
Quantity to be transported in city 1
Nb. SmallTrucks needed to transport
the quantity demanded in city 1
City 2
City 3
City 4
=Total quantity to be transported in
the sector
Nb. BigTrucks needed to transport
the total quantity demanded in the
sector
Total Quantity
of the secteur
Fig. 6 Table of repartition of the quantities between cities (retailers) within a sector
Keeping the actual repartition of the selling
points in the five sectors yet defined by the
company, the aim of this study is primarily to
determine the optimal location for the intermediate warehouse in each region in order to
minimize the distribution cost by using the
algorithm proposed in section three. Secondly,
by comparing the costs in the case of using
intermediate warehouses and in the case of direct distribution a choice for the proper distribution network can be made. In the end some
observations will be made regarding the differences between the actual and the proposed
distribution architecture.
The products are transported with standard
boxes placed on europallets. A standard box
is the count unit for the quantity to be transported. Its standard dimensions (Eurobox) are
0,850m x 1,240m x 0,970m, that is 1m3. The big
trucks that have been chosen have a capacity of
84m3 and the small ones of 42m3 or of 20m3.
The algorithm is run using quantities sold in
2008 by the company in each city of the five
sectors. As this company works in Just in Time
( JIT), the reduction of stocks comes as a priority. Therefore, a new constraint will be inSector
troduced in the general algorithm presented in
section three, that is the need for daily distribution to each selling point. This means that the
quantities which are going to be introduced in
the algorithm will be daily quantities instead of
annual quantities.
After running the data, the algorithm indicates
the following locations for the warehouses(table
1). The analysis that was made pointed out that
by further dividing the South Region (which is
comparatively bigger than the others) and by
placing in each new division an intermediate
warehouse instead of using direct distribution
(as the company does today) the cost of transport can be further lowered.
An important observation would be that the
appropriateness of the location of the platforms is kept in time as long as the repartition
of sales within each sector stays the same. This
hypothesis is weak and verifiable as the repartition of sales between selling points within
a sector is directly influenced by population
characteristics (such as for instance the population number or the purchasing power of the
inhabitants) which are inelastic in short and
medium run.
Location of intermediate
warehouse (algorithm)
Location of the real location of
the intermediate warehouse
1
BANAT
Caraş-Severin
Timişoara
2
TRANSYLVANIE
Mureş
Cluj
3
REGION DU SUD DU PAYS
ET BUCAREST
Direct distribution
Region Z1
Ploieşti
Region Z2
Slobozia
Region Z3
Buzău
4
MOLDAVIE
Bacău
Bacău
5
DOBROGEA
Constanţa
Constanţa
Table 1 Location of regional warehouses in each sector (algorithm)
22
UNDERSTANDING WHEN
INTERMEDIATE WAREHOUSES ARE
A BETTER SOLUTION THAN DIRECT
DISTRIBUTION
The results obtained in this case study have
pointed out the relative efficiency of a distribution architecture using intermediate warehouses compared to direct distribution so
as to minimize the transportation costs. By
analyzing the results, we can observe that the
efficiency of using intermediate warehouses is
high as long as the individual quantity which
has to be distributed to each city of a geographic sector does not allow its direct transport by big capacity trucks at a high loading
rate. By contrast, if the merchandise that has
to be transported to a specific city is large
enough so as to be transported by large trucks
at full capacity (or there is the possibility to
wait until this happens), direct transport becomes the optimal choice.
CONCLUSION
Today companies have to optimize their resource planning and use in order to gain competitiveness on global markets. Against this
background, optimizing transport of goods is a
must. The algorithm proposed in this paper allows for taking a decision between a direct and a
distribution network using regional warehouses
in order to minimize the costs of transportation.
Romanian companies have to keep up with the
transformations of the logistic chain in the context of globalization and to start to conduct more
accurate management accounting and feasibility
studies in order to search for ways of optimizing
the use of their resources. The European integration offers great opportunities but it means as
well stronger competition and thus the imperative need for optimization the use of resources.
Bibliography:
[1] MANEA C., Variables stratégiques dans
l’emplacement des plateformes intermédiaires logistiques, Bachelor’s Degree Thesis, Economics
Studies Bucharest, 2009
[2] MANEA A. T., MANEA L.C., Utilaje
de transport rutier în zona portuară, Editura
MatrixRom Bucureşti, 2004, ISBN 973-685704-2.
[3] SERRE, G., L’entrepôt dans la chaîne logistique d’un industriel de grande consommation,
CGPC presentation, 2002.
ANNUAL SESSION OF SCIENTIFIC PAPERS „IMT ORADEA – 2011”
Oradea, Felix Spa, May 26-28th, 2011
This scientific event has an international character and is addressed to all engineers and specialists interested in automotive, mechanical engineering, industrial engineering, mechatronics and
economic engineering. Website of the event is:
http://imtuoradea.ro/conf/
Journal “Annals of Oradea THE UNIVERSITY.
BEAM OF MANAGEMENT AND ENGINEERING Technological “, ISSN 1583 - 0691, publishes the papers presented at this conference
and is an engineering scientific publication of the
Faculty for Managerial and Technological Engineering of the University from Oradea. Its first
number appeared in 1991 and this year celebrated 20 years. Between the years 2004-2007, was
accredited CNCSIS magazine in the “Class B”
and from 2007 to the present is accredited CNCSIS “Class B +”.
In 2011, the event was held under the patronage of: (SIAR), Society of Automotive Engineers
of Romania, General Association of Romanian
Engineers - Branch Bihor (AGIR) (ENCS) - National Authority for Scientific Research - Grant
2011, Reasearch Center “Production IMT-Oradea “, Reasearch Center in Mechanical Engineering and Automotive” IMA “Oradea, Romanian
Association for Non-Conventional Technologies
- Branch Bihor (ARTN)
MAIN THEMES
ENGINEERING OF AUTOMOTIVE AND
TRANSPORTS: New solutions for automoti-
ve engines, automotive and the environment,
transport systems and advanced traffic, advanced
manufacturing methods for automotive, new materials, logistics and manufacturing technologies
for automotive
MECHANICS: Mechanics, Strength of Materials, Mechanical Vibrations, Numerical Methods,
Applied Mathematics, machinery and equipments
MECHATRONICS: Industrial robots, Mechanisms, Machine, Fine Mechanics, Tribology, sensors, AI, pneumatic and hydraulic systems
MANUFACTURING ENGINEERING: Techniques CAD / CAM, flexible and integrated
systems, materials, unconventional technologies,
CNC Technologies
MANAGEMENT AND ECONOMIC ENGINEERING: Management of production systems, human resources, marketing, quality engineering, industrial logistics and material planning,
risk management, knowledge management
Total number of scientific papers published: 245
PLENARY SESSION
1. Matúš Duňa, Marek Miško, High precision gearboxes by SPINEA, SPINEA s.r.o.
COMPANY, Prešov, Slovakia. 2. Ciolofan
Constantin, Integrated CAD / CAM / CAE /
PLM Last Generation Program System, INAS
SA Romania 3. Gheorghe Florea, VERSAROLL
system - applied to the assembly lines of automotive body, COMAU Romania. 4. John
Lucaciu Mircea Burca, RESEARCH ON THE
DEVELOPMENT OF HETEROGENEOUS
MATERIALS WELDING TECHNOLOGY,
University of Oradea. 5.Florin Blaga, Julian
Stănăşel, Calin Baban, Marius Baban - Developing
the skills of concurrent engineering, University of
Oradea.
Of the over 330 authors and co-authors of papers
accepted for publication, the thermal resort hotel
Felix Bale attended 117 participants from Romania
and 22 from abroad, most from Hungary, but also
from Spain, Slovakia and Serbia. In terms of educational institutions at the event were represented
14 universities from Romania and 6 from abroad.
Economic media were less represented than in
previous years, being present only eight companies from Romania and one from abroad.
At the end of the two days one could say that this
annual meeting had a high scientific level, the large number of participants showing real interest
for this event. The purpose was achieved, generating and ensuring the conditions for the dissemination and information transmission of the
research results in areas that were the subject of
the five sections.
Next year, during May 31st-June 15t, 2012 will
take place the event „IMT-Oradea 2012“, edition 21, under the coordination of the Faculty for
Managerial and Technological Engineering in
Spa Felix, Hotel. The conference will include the
same sections as the previous edition.
Images of the place and the manner of operation of scientific session
23
The laboratory for performances certification of electro-hydraulic amplifiers
University Politehnica of Bucharest
Laboratory accredited by RENAR LI 821/2009; SR EN ISO 9001:2008b Certificated
[email protected]
http://www.fluid-power.pub.ro/
Destination: Certification
of static and dynamic of
electro-hydraulic servovalves performances, proportional distribuitors, proportional valves; static and
dynamic testing for high
speed electro-hydraulic servomechanisms of dynamic stress simulators, adaptive servo-steering
for road vehicles, hydraulic shock-absorbers,
ABS, ESP systems, electromagnetic and piezokeramic injectors etc.
Permanent collaborations:
- Platform of Road Vehicles in UPB;
- Renault Technologie Roumanie;
- INOE hydraulic and pneumatic Institute;
- Hidroelectrica SA, Termoelectrica SA,
Rompetrol;
- Parker Hannifin Romania, CEROB, Hidraulica
Brasov, HESPER SA, BOSCH-REXROTH RO ;
- National Instruments, LMS International,
Filiala BV
- ICPE-ACTEL SA, AEROTECH SA, ROMET
BUZAU.
Director : Prof.dr.eng. Nicolae Vasiliu
24
University Research
Project HURO/0901/258/2.2.2, Project title: Research on engines in a single regime running
Lead Partner: University of Oradea
Project Manager: Conf. Dr. Ing. CHIOREANU Nicolae, University of Oradea
Expert’s team: Conf. dr. ing. Chioreanu Nicolae, Prof. dr. ing. Antal
Cornel, Prof. dr. ing. Băban Călin, Prof. dr. ing. Pop Mircea, Prof. dr. ing.
Rus Alexandru, Conf. dr. ing. Mitran Tudor, Conf. dr. ing. Nemţanu
Marius, Conf. dr. ing. Vesselenyi Tiberiu, Ş.l. dr. ing. Beleş Horia, Ş.l. dr. ing.
Dragomir George, Ş.l. dr. ing. Fântână Nicolae, Ş.l. Dr. ing. Spoială Viorica,
Ş.l. dr. ing. Şchiop Adrian, ing. Crăciun Dan, Prep. Ardelean Felician
Partner. Szent Istvan University, Gödöllõ, Ungaria
General objective: Knowledge and skills on design and manufacture of engines (thermal and electrical) running in a single regime. The study of the
possibility to use these engines for cars propulsion systems.
General presentation: Overall objective of the project is to implement the
economic cycle of new types of engines. The new engines represent an absolute novelty and are characterized by the following features: running in a
single regime (monoregim); without moment’s idle running. The following
advantages are estimated :(compared to the nowadays internal combustion
engine or electric motors): less fuel or electrical energy consumption and
lower polluting emissions (it is much easier to optimize a single regime to
an infinite as current production engines), simple construction, and good
viability. Also, the monoregim engine can assume, totally or partially.
Contact: E-mail: [email protected].
Traffic survey portable electronic counter
Electronic counter set is the result of collaboration between Technical
University of Cluj-Napoca and Cerberus Company Soft.
It is intended to carry out surveys of traffic activity that so far, in the country, has been made only manually by operators, thus requiring a large number of people engaged in this activity.
The presented equipment is patented and registered under OSIM no.
019017/26.02.2010.
Technical specs: Dimensions: 220x120x65 mm, - weight: 640g; Power
source: 4 AA of 2500mA battery, charger fit to national power grid; Internal
memory: 1Gb; Range of working temperature: - 10 - 80 °C (no condensation); number of recorded moving directions: 12; number of vehicle categories: 8; connectivity: USB; autonomy: 36 de ore.
Working conditions: Electronic traffic counter is portable electronic
equipment, dedicated exclusively to carrying out traffic surveys. In order to
simplify the text and speech, it will be mentioned throughout this document
and the software under the generic name „Palm”. In terms of the degree of
mechanical and electrical safety, traffic counter is within the standard IP52.
For prolonged use, the device will be protected from mechanical shock and
exposure to damp and will not be allowed subject to direct solar radiation
for a long time. Electronic traffic counter is portable electronic equipment,
dedicated exclusively to carrying out traffic surveys. Powering with electric
energy of the traffic counter is achieved through Ni-MH of 2500mAh,
User interface, data transfer and other information’s on exploitation of rte
electronic counter: Contact Nicolae Filip.utcluj.ro
Welding Research on composite materials used in construction of intelligent cars
Authors: Prof. univ. dr.eng. Gheorghe Amza, Lecturer Eng. Zoia
Apostolescu
The work includes technology to achieve optimal intelligent taillights and
smart bars used in construction vehicles using near-field ultrasonic welding.
It makes a comparative analysis quality / price of several welding proce-
dures to be applied resulting in the possible optimal method - ultrasonic
welding. Welding operation is performed with an ultrasonic welding torch
original design.
Contact: Prof. Univ. dr. eng. Gheorghe Amza, [email protected]
Talon de abonament
Doresc să mă abonez la revista Auto Test pe un an
(12 apariţii „Auto Test” şi 4 apariţii supliment „Ingineria
Automobilului”)
Subscription Form
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(12 issues of „Auto Test” and 4 issues of it’s supplement
„Ingineria Automobilului”)
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Preţul abonamentului anual pentru România: 42 lei. Plata se face
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RO78BRDE410SV19834754100.
25
Participation of students from University of Piteşti at Challenge KART LOW COST,
a result of a good collaboration with University of Bourgogne,
ISAT of Nevers, France
Adrian CLENCI
Universitatea din Piteşti
Departamentul Automobile
Ernest GALINDO
Université de Bourgogne
Institut Supérieur de l’Automobile et des Transp.
http://kartlowcost2011.free.fr/
Challenge Kart Low-Cost.
What does it mean?
Developing of a kart over one academic year,
whose cost is not to exceed 2000 €, aiming to
participating in May to a motor-sport academic
competition.
This project underlines the basic competences
of an engineer, such as:
 Teamwork/organization of a team in
such way that deadlines are to be respected,
 Capability to select engineering solutions, having constraints of budget and
time,
 Ingeniousness, etc.
Therefore, it’s not just a simple go-karting race.
Equally, it’s a technological, educational and human challenge and the winner is not necessarily
the fastest!
For whom?
This competition, whose aim is to develop a socalled “low-cost” by multidisciplinary student
teams, is opened to anyone concerned by the
automotive engineering
The students are gathered in teams and over one
academic year, they follow the development
stages of a product, so that in the end the motorsport competition to be possible.
In 2011, the competition took place on a track
of the many presented on the former site of
France’s F1 Grand Prix at Magny-Cours (F-58)
and the competitors were: Institut Supérieur de
l’Automobile et des Transports de Nevers from
the University of Bourgogne (one team) and
University of Pitesti (two teams) - http://www.
upitmedia.ro/index.php/unctr/universitateadin-piteti-la-kart-low-cost-challenge.html
Challenge Kart Low-Cost. Goals
 Learning/exercising of all stages of a
product’s development (design, manufacturing, etc)
26
 Understanding the problems that occur
from the need to obtain an optimal operational product, as a result of a coherent
compromise, corresponding to precise
technical specifications,
 Encouraging the innovation by imposing of a permissive technical regulation,
leaving a great freedom of design, thus
allowing students the development and
application of their ideas,
 Development of a product, respecting
the constraints of budget and time,
 Development of competing spirit
amongst students,
 Encouraging students to seek out for
complementary competences, allowing
them to open their minds, which is indispensable for the future professional life,
 Introduction of students in a frame
which encourages reflection toward what
the automotive engineering really means
and which allows opinions exchanges
with people from different nationalities
aiming also to create a cultural exchange.
Briefly, the goal of this competition is to prepare
future engineers for project management by developing the teamwork spirit, sharing responsibilities, respecting deadlines and allocated budget; finally, it aims to develop the synthesis and
compromise capabilities in respect to the initial
imposed constrains.
Project evaluation
 Analysis of the expenses (≤ 2000 €),
 Analysis of the kart’s body design,
 Dynamic tests, allowing to evaluate the
kart’s dynamics as well as its acceleration,
 Endurance test (60 laps) in order to analyze the kart’s reliability.
Challenge Kart Low-Cost. 2012 edition
Following an agreement in progress of being validated, between Renault Romania and
University of Pitesti, the next edition will be organized on test tracks of Renault – Dacia from
Merisani Arges.
In 2012, taking into account the current orientation of the automotive industry, ISAT de Nevers,
the author of this competition, decided to introduce another challenge, the electric propulsion;
thus, there will be two competitions: one with
thermal powered karts and another one with
electrical powered karts.
Therefore, Romanian universities having
Automotive Engineering specialization are invited to be part of.
Series of Lectures at the
University of Braúov
Beginning with May 2011 the University Transylvania organizes, at regular intervals,
a series of technical lectures together with Schaeffler Technologies GmbH & Co. KG
and with other renowned partners from the automotive community.
Leaders of the automotive
science and industry
yp
present
Initiator
The series of technical lectures will be continued in the academic year
of 2011/2012. The conferences for 2011 are scheduled at the
beginning of October, November and December respectively.
Our speakers are:
Partners
Dr.-Ing. Kurt Kirsten,
Vicepresident of Schaeffler Group Automotive, Herzogenaurach / Germany
Prof. Dr.-Ing Adrian Rienäcker and Prof. em. Dr.-Ing. Günter Knoll
Unversity of Kassel / Germany
Prof. Dr.-Ing. Giovanni Cipolla
University of Torino / Italy, former head of engine development at Ferrari in Maranello
The speakers will present new concepts for the development of future
mobility, as well as possibilities for tribological improvements in the
propulsion systems of road vehicles.
The lectures will be video transmitted in real-time to the
Technical University of Cluj
Cluj-Napoca
Napoca and the
Technical University "Gheorghe Asachi" of Iaúi.
Conference dates and subjects will be announced two weeks
prior to each event.
Westsächsische
Hochschule
Zwickau
We are looking forward to meeting you!
auto test 3

Ingineria Automobilului Society of

Transcription

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