Mars 2015 4 Number 1 - ingineria-automobilului.ro · RoJAE vol. 21 no. 1/ Mars 2015 ISSN ____ –...

ISSN ____ – ____ (Online, English) ISSN 1842 – 4074 (Print, Online, Romanian)

Mars 2015 Volume 21

4 th Series Number 1

RoJAE

Romanian Journal of Automotive Engineering

The Journal of the Society of Automotive Engineers of Romania www.siar.ro www.ingineria-automobilului.ro

SIAR – Society of Automotive Engineers of Romania is member of:

FISITA - International Federation of Automotive Engineers Societies www.fisita.com

EAEC - European Automotive Engineers Cooperation

RoJAE Romanian Journal of Automotive Engineering

Societatea Inginerilor de Automobile din România Society of Automotive Engineers of Romania

www.siar.ro SIAR – The Society of Automotive Engineers of Romania is the professional organization of automotive engineers, an independent legal entity, non-profit, active member of FISITA (Fédération Internationale des Sociétés d'Ingénieurs des Techniques de l'Automobile - International Federation of Automotive Engineering Societies) and EAEC (European Cooperation Automotive Engineers). Founded in January 1990 as a professional association, non-governmental, SIAR’s main objectives are: development and increase the exchange of professional information, promoting Romanian scientific research results, new technologies specific to automotive industry, international cooperation. Shortly after its constitution, SIAR was affiliated to FISITA - International Federation of Automotive Engineers and EAEC - European Conference of Automotive Engineers, thus ensuring full involvement in specific activities undertaken globally. In order to help promoting the science and technology in the automotive industry, SIAR is issuing 4 times a year RIA - Journal of Automotive Engineers (on paper in Romanian and electronically in Romanian and English). The organization of national and international scientific meetings with a large participation of experts from universities and research institutes and economic environment is an important part of SIAR’s. In this direction, SIAR holds an annual scientific event with a wide international participation. The SIAR annual congress is hosted successively by large universities that have ongoing programs of study in automotive engineering. Developing relationships with the economic environment is a constant concern. The presence in Romania of OEMs and their suppliers enables continuous communication between industry and academia. Actually, a constant priority in SIAR’s activity is to ensure optimal framework for collaboration between universities and research, industry and business specialists.

The Society of Automotive Engineers of Romania President Adrian Constantin CLENCI University of Pitesti, Romania E-mail: Honorary President Mihai Eugen NEGRUS University „Politehnica” of Bucharest, Romania Vice-Presidents Cristian Nicolae ANDREESCU University „Politehnica” of Bucharest, Romania Nicolae BURNETE Technical University of Cluj-Napoca, Romania Anghel CHIRU „Transilvania” University of Brasov, Romania Victor OTAT University of Craiova, Romania Ion TABACU University of Pitesti, Romania General Secretary Minu MITREA Military Technical Academy of Bucharest, Romania

Honorary Committee of SIAR

Sorin BUSE Renault Technologie Roumanie

www.renault-technologie-roumanie.com George-Adrian DINCA

Romanian Automotive Register www.rarom.ro

Florian MIHUT The National Union of Road Hauliers from Romania

www.untrr.ro Werner MOSER

AVL Romania www.avl.com

RoJAE


CONTENTS

Volume 21, Issue No. 1 Mars 2015

Efficiency Calculation of an Unpublished 2 Strokes Engine, with Spherical Chamber and Over Power Stroke Edouard BONNEFOUS and Julien MARCINKOWSKI................................................................

5

Experimental Research on the Hybridization of a Road Vehicle Dan Mihai DOGARIU, Anghel CHIRU, Cristian Ioan LEAHU and Marius LAZAR.....................

15

Presentation of a Wheel Loader with an Electric Driven Pump and With Electric Wheel Drives Michael BUTSCH, Uwe KOSIEDOWSKI, Peter KUCHAR, Manfred MACK and Dimitri ZIMANTOVSKI................................................................................................................................

21

Globalization of the Automotive Industry – Focus On German Automotive Manufacturer's Vijay NARAYANAN, Axel MAURER and Lucian RAD....................................................................

25

Research Regarding the Influence of Biofuels on the Law of Heat Release from a Diesel Engine Bogdan BENEA, Anghel CHIRU and Gabriel MITROI ..................................................................

29

The collections of the journals of the Society of Automotive Engineers of Romania are avaibles at the Internet website www.ro-jae.ro. The Romanian Journal of Automotive Engineering is indexed/abstracted in Directory of Science, WebInspect, GIF - Institute for Information Resources, MIAR - Information Matrix for the Analysis of Journals - Barcelona University, Georgetown University Library, SJIF - Scientific Journal Impact Factor - Innovative Space of Scientific Research, DRJI - Directory of Research Journal Indexing - Solapur University, Platforma Editorială Română SCIPIO – UEFISCU, International Society of Universal Research in Sciences, Pak Academic Search, Index Copernicus International RoJAE 21(1) 1 – 34 (2015) ISSN ____ – ____ (Online, English) ISSN 1842 – 4074 (Print, Online, Romanian)

RoJAE

Romanian Journal of Automotive Engineering Editor in Chief Cornel STAN West Saxon University of Zwickau, Germany E-mail: [email protected] Executive Editor Nicolae ISPAS „Transilvania” University of Brasov, Romania E-mail: [email protected] Deputy Executive Editor Radu CHIRIAC University „Politehnica” of Bucharest, Romania E-mail: [email protected] Ion COPAE Military Technical Academy of Bucharest, Romania E-mail: [email protected] Stefan TABACU University of Pitesti, Romania E-mail: [email protected] Editors Ilie DUMITRU University of Craiova, Romania E-mail: [email protected] Marin Stelian MARINESCU Military Technical Academy of Bucharest, Romania E-mail: [email protected] Adrian SACHELARIE „Gheorghe Asachi” Technical University of Iasi, Romania E-mail: [email protected] Marius BATAUS University „Politehnica” of Bucharest, Romania E-mail: [email protected] Cristian COLDEA Technical University of Cluj-Napoca, Romania E-mail: [email protected] George DRAGOMIR University of Oradea, Romania E-mail: [email protected]

Advisory Editorial Board Dennis ASSANIS

University of Michigan, USA Rodica A. BARANESCU

Chicago College of Engineering, USA Nicolae BURNETE

Technical University of Cluj-Napoca, Romania Giovanni CIPOLLA

Politecnico di Torino, Italy Felice E. CORCIONE

Engines Institute of Naples, Italy Georges DESCOMBES

Conservatoire National des Arts et Metiers de Paris, France Cedomir DUBOKA

University of Belgrade, Serbia Pedro ESTEBAN

Institute for Applied Automotive Research Tarragona, Spain Radu GAIGINSCHI

„Gheorghe Asachi” Technical University of Iasi, Romania Eduard GOLOVATAI-SCHMIDT

Schaeffler AG & Co. KG Herzogenaurach, Germany Peter KUCHAR

University for Applied Sciences, Konstanz, Germany Mircea OPREAN

University „Politehnica” of Bucharest, Romania Nicolae V. ORLANDEA

University of Michigan, USA Victor OTAT

University of Craiova, Romania Andreas SEELINGER

Institute of Mining and Metallurgical Engineering, Aachen, Germany

Ulrich SPICHER Kalrsuhe University, Karlsruhe, Germany

Cornel STAN West Saxon University of Zwickau, Germany

Dinu TARAZA Wayne State University,USA

The Journal of the Society of Automotive Engineers of Romania www.ro-jae.ro www.siar.ro Copyright © SIAR Production office: The Society of Automotive Engineers of Romania (Societatea Inginerilor de Automobile din România) Universitatea „Politehnica” din Bucuresti, Facultatea de Transporturi, Splaiul Independentei Nr. 313 060042 Bucharest ROMANIA Tel.: +4.021.316.96.08 Fax: +4.021.316.96.08 E-mail: [email protected] Staff: Prof. Minu MITREA, General Secretary of SIAR Subscriptions: Published quarterly. Individual subscription should be ordered to the Production office. Annual subscription rate can be found at SIAR website http://www.siar.ro. The members of the Society of Automotive Engineers of Romania receive free a printed copy of the journal (in Romanian).

RoJAE vol. 21 no. 1/ Mars 2015 ISSN ____ – ____ (Online, English) Romanian Journal of Automotive Engineering ISSN 1842 – 4074 (Print, Online, Romanian)

5

EFFICIENCY CALCULATION OF AN UNPUBLISHED 2 STROKES ENGINE, WITH SPHERICAL CHAMBER AND OVER POWER STROKE

Edouard BONNEFOUS1)*, Julien MARCINKOWSKI2)

1) Zodiac Aero Electric , Montreuil sous Bois - 93, France

2) Valeo Engine and Electrical Systems, France

(Received 19 January 2015; Revised 12 February 2015; Accepted 25 February 2015)

Abstract: The unpublished 2 strokes engine, described in the patent’s demand n°1301584 [1] presents by its original kinematic configuration, a quasi-spherical combustion chamber at top dead centre and around, so dividing by more than 2 the ratios surface and forces/volume compared with a classic engine with piston. Furthermore, its ports distribution authorizes to set freely four moments of opening and closing of the ports of intake and exhaust, to increase the thermodynamic efficiency by a Miller cycle. The present article concerns the 1D modelling in 2 zones of the thermodynamic cycle of such an engine. The resolution of the equations is numerically realized under Matlab and the various models are validated on an equivalent classic engine. Considering a forehead of spherical flame centred on the spark plug, the model of combustion developed for this study allows to calculate the position, the surface and the speed of propagation according to the aero-thermodynamics parameters and the rate of residual burned gases. Besides, the walls contact areas with the burned and not burned gases, which differ strongly between the unpublished engine and the classic equivalent, are known so at each moment, what allows estimating finely the losses at walls by a model of Woschni. The optimal parameters (ports diagram, spark advance, pressure of scavenging, etc.) were retained for every point of engine’s normal operation. Key-Words: Internal combustion engine, 2 strokes, uniflow scavenging, over power stroke, Miller cycle, compact chamber, spherical chamber, thermodynamic efficiency, model of combustion, models of heat losses at walls, Woschni, Matlab, internal aerodynamics, turbulence, bi-zones model of combustion.

1. INTRODUCTION In order to evaluate the performances and efficiency of an unexpected engine, we developed a specific model of simulation of thermodynamic two strokes cycles spark ignited, with Matlab software. First, we used this model to simulate a classical two strokes engine, in order to determinate values of different parameters to get the most accurate behaviour. Then we conserved the values of those parameters in order to simulate in a predictive way this unexpected engine with equal displacement and effective compression ratio. 2. GENERAL DESCRIPTION OF THE MODEL 2.1 Modelling with two zones We chose a modelling of the thermodynamic cycle with two zones: a zone of unburned gas under quoted u (for "unburned") and a burned gas zone under quoted b (for "burned"). Such a modelling can be

considered as mono-dimensional because considering a flame front spherical centred on the spark plug at each crankshaft angleθ , it gives the position of the flame front between the two zones. That allows

knowing the contact surface between the two zones and between the zones and the chamber walls. We will be precisely able to evaluate the thermal losses at chamber wall to reduce them and facilitate the best propagation of the flame front during combustion. We will act on those two key points of the Unexpected engine, beyond the intrinsic effect of the spherical chamber at top dead centre, thanks to adaptation of internal aerodynamic by sensibly positioning of the unique or several spark plug(s).

* Corresponding author e-mail: [email protected]


6

2.2 Equations system

For each zone i , we must calculate for each crank angle θ its volume iV , its mass im and its

temperature iT and the pressure P common at the two zones.

So we get a system comprising 2 x 3 + 1 = 7 unknown with the following equations:

• 2 mass balance sheet of with a sub-model of transfer calculating the flow at ports with the equation of “Barré de St Venant”

• 2 equations of perfect gas

• 2 first principle of thermodynamics for open systems The sum of the volumes of the two zones equals the total volume of the chamber 2.3 Sub-model of combustion Considering that the flame is developing itself in a spherical way from the unique of several spark plugs, by knowing the total volume of the chamber and burnt gas at one given moment, allows us, thanks to cartographies from Catia CAD numerical mock-up of different engines, to know the radius and surface

fS of the flame front. The sub-model of combustion phenomenological developed for this study allows

then to calculate the speed TS (Turbulent Speed) of flame propagation according to aero-

thermodynamic parameters. We can finally deduct from it the flow of not burned gases being transformed into gases so burning and changing zone by the relation:

uufTufT

Rb

Tr

PASAS

dt

dm== ρ

, (1)

This equation is true in the field of homogeneous mixtures close to stoechiometry, the considered case. Karlovitz [2] suggested connecting the speed of turbulent flame with its laminar value by the formula:

uSS LT ′+= (2)

where u′ is the speed characterizing the turbulence

This formula was taken back and completed by numerous authors such as Abdel-Gayed and Bradley [3]

or the Driving Scientific Grouping [4]. To calculate the speed of laminar flame LS , we retained the

correlations proposed by John B. Heywood [5].

Besides, we considered that the characteristic speed of the turbulenceu′ :

Was directly proportional at the average speed of the flow U in the chamber, calculated from:

• average flow rate at the ports during scavenging,

• speed of moving walls of the chamber (which is piston speed for a classical engine)

• and the chamber shape Was quickly decreasing from the TDC to simulate the disintegration of the flow by crushing of a macro whirlwind (movement of tumble for the classic engine)

To calibrate the values of the various constants of this model, we determined them to obtain for the classic engine a realistic generated heat, modelled by a curve of Wiebe. 2.4 Sub-model of heat transfer The approach developed above and allowing to determine the surface of flame also gives us the contact area of gases of the zone i with the walls of the chamber. We can then calculate the flow of heat lost by convection in walls by:

( )iwalliii TTSh

dt

dQ−= (3)

where wallT is the temperature of the walls (250°C at full load) and 8,053,08,0 UTPh ii−=α is the

coefficient of convection according to Huber's model, Woschni and Zeilinger.


7

The fitting coefficient α is determined by kind to obtain for the classic engine of heat losses in walls of

the order of the third of the energy released by the fuel during the combustion in the full load. 3 DESCRIPTION OF THE CLASSIC AND UNPUBLISHED ENGINES, SIMULATED

3.1 General characteristics

Table 1 Characteristics of engines

Figure 1. Twin zones model A volumetric compressor synchronous with the crankshaft, the admission of which we can sieve by a throttle allows supplying the pressure of scavenging. We considered constant and respectively equal isentropic and mechanical efficiencies in 70 % and 90 % (debatable according to the type of transmission and the lubrication, but identical for both models).

Figure 2. Scheme of the classic engine and notes

3.2 Shape of the chamber of the unpublished engine The chamber of the unpublished engine is similar all the time to a regular octahedron, the volume of which is variable thanks to 4 "pistons" each in translation to each other. Besides, every piston has a cap so that in the TDC the chamber is almost spherical. Contrary to the classic engine where the cylindrical volume of the chamber evolves only by a variation of its height, thus in a single direction of the space, the chamber of the Unpublished engine realizes a homothecy in all the directions of the space. Besides the optimization of the surface / volume ratio compared with the classic engine, straight from total volume and of burned gases, the flame will have fewer interactions with walls and will so have one larger surface. To avoid a too abrupt combustion which would increase the losses in walls, we can then reduce the speed of gases in the cylinder to preserve a suitable burning time while decreasing the losses in walls by decrease of the coefficient of convective exchange.

Classic engine

Unpublished engine

Bore/stroke ratio 1 N/A

Rod/crank ratio 2,5 N/A

Shape of the chamber Cylindro-conic

Quite spherical

Unitarian displacement

520 cm3

Geometrical compression ratio

16,6:1

Actual compression ratio 10,2:1

P, Vb, mb, rb, Tb

P, Vu, mu, ru, Tu

P1, T0 P2, T2 P3

P, Vb, mb, rb, Tb

P, Vu, mu, ru, Tu

P0, T0

Papillon

des gaz

Compresseur

volumétrique

Injection Allumage

Admission Echappement


8

Figure 3. Evolution of the volume of the chamber of the Unpublished engine. Views from the 3D digital model used in particular to calculate the laws of volume and surface.

3.3 Laws of surface and volume and diagrams of timing of both engines Graphs below present the surface and the volume totals of the chamber according to the crankshaft angle θ for the unpublished engine (moteur Inédit) and its classic equivalent. We notice besides that the unpublished engine presents a better surface / volume ratio and is more isochoric in the TDC than its classic equivalent. The figure below presents the timing diagrams of the 2 engines. Figure 4. Surface [cm2] and volume [cm3] of the chamber according to the crank angle [°] from the TDC

(0 °) to the BDC (180 °)

θ = 0° (BDC)

θ = 90°

θ = 135° θ = 180°

(TDC)

Piston 1

Piston 2

Piston 3

Piston 4

Caps

0

100

200

300

400

0 30 60 90 120 150 180

Surface chambre moteur Inédit

Surface chambre moteur classique

Surface du volume idéal sphérique

0

100

200

300

400

500

600

0 30 60 90 120 150 180

Volume chambre moteur Inédit

Volume chambre moteur classique


9

Figure 5. Timing diagram of the 2 engines, simulated

3.4 Variation of the number and the position of spark plugs In the case of the unpublished engine, we wanted to test various numbers and positions of spark plugs. We then made the simplifying approximation that the chamber remained strictly spherical in the neighbourhood of the TDC, is during all the combustion, which is very close to the reality. So, every mapping of contact area according to the total volume and to the burned gases is replaced by a simple curve giving the ratio of the contact area onto the total surface according to the ratio of the volume of gases burned on the total volume. For every configuration, this curve is obtained by an approach CAD simplified by intersection between various spheres an example of which for 2 spark plugs diametrically opposed is presented below.

Figure 6. Evolution of the volume of burned gases (dark red) and the surface of flame for 2 diametrically opposed spark plugs in a spherical chamber

0

60

120

180

240

300

360

420

480

540

600

0

2

4

6

8

10

12

14

16

18

20

180 210 240 270 300 330 360 390 420 450 480 510 540

Volume de chambre [cm3]

Section des lumières [cm2]

Angle vilebrequin [°]

Adm. Inédit

Ech. Inédit

Adm. classique

Ech. classique

Vol. Inédit

Vol. classique


10

4 SIMULATION RESULTS AT 2000 rpm, FULL LOAD 4.1 Classic engine The following curves present respectively the cylinder’s pressure (the pressure without combustion is drawn for information in dotted lines), the masses of unburned and burned gases and a zoom on the gas flow passing from a zone to the other one (what represents the image of the release of energy) according to the crank angle.

Figure 7. Pressure, masses and flow rates The following figure presents the energy balance resulting from this simulation. The variables of the model of combustion and the fitting coefficient of the heat losses in walls were chosen by kind to realistically reproduce a shape of cylinder pressure, energy release and energy balance. The values so obtained were kept the same for the unpublished engine. The classic engine presents an indicated efficiency of 34 %. 4.2 Unpublished engine (case with centred timing) The configuration of ignition includes 2 spark plugs opposed on the sphere. The timing is centred on the BDC. The pressure of intake is 1,025 bars. The spark advance is 25°. The following curves present respectively the cylinder pressure, the masses of fresh and burned gases and the flow of gas passing from a zone to the other one, according to the crank angle.


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Figure 8. Balance of energy

Figure 9. Pressure, masses and flow of burning


12

The next figure presents the balance of energy resulting of this relevant simulation, because it resumes the variables of the model of combustion and the fitting coefficient of heat losses by convection at walls identical to the model of classic engine, to which these coefficients were fixed. The efficiency reaches 40%, superior by 18% to the classical engine.


4.3 Unpublished engine (case with Miller cycle or over power stroke) The timing diagram is not any more characterized by openings of ports centred all around BDC, but with angles of closing and openings of exhaust and intake moved by 16,5 ° of crank angle, to allow an effective over power stroke of 73 %, compared to the effective displacement of compression.

Figure 11. Timing diagram with Miller cycle The intake displacement being lower on this model and being approximately worth 250 cm3, the law of volume was decreased in a constant to preserve an actual compression ratio of 10,2:1. The law of surface is also corrected by a constant, to correspond to a spherical chamber at the TDC. The configuration of ignition contains here sparks situated closer to the centre of the sphere. The following curves present respectively the cylinder pressure (the pressure without combustion is drawn for information purposes in dotted lines), the masses of burned and unburned gases and a zoom on the gas flow passing from a zone to the other one (what returns to the release of energy) according to the crank angle. The peak pressure is still increased because of spark configuration. We notice the decrease of effective intake displacement, because of intake mass diminution. The gas flow of the fresh zone to burn is hardly upper because of the configuration of ignition which requires a geometrical distance to be browsed by the flame front, slightly shorter. The energy balance below indicates a 46 % efficiency that is a 12 % improvement compared with the previous configuration. The improvement of efficiency, compared with the classic engine is of (46%-34)/34% = 35 %.


13

Figures 12. Pressure, masses and flow of burning



14

5 CONCLUSION Within an internal combustion engine, the energy of the fresh mixture is gradually transformed at first into heat by combustion then into mechanical work and heat losses in walls, heat and remaining pressure characterizing the enthalpy in the exhaust. So the decrease of heat losses in walls would allow increasing possibly the efficiency and the level of enthalpy available on the exhaust. To achieve it, it would be advisable in particular to reduce the surface/volume ratio, and it especially as the temperature and the turbulence are important, that is around the TDC. The concept of piston motors, connecting rod and crank, among which the shape of chamber and the kinematics are dictated by numerous imperatives and compromises, seem to have reached the asymptote of the reduction of these losses, while they remain all the same very important. A more elaborate optimization thus requires a change of paradigm. By rethinking completely the kinematics and the shape of the chamber, the unpublished engine with quasi-spherical chamber allows to decrease strongly the surface/volume ratio and the need in aerodynamics with for consequence an important reduction of heat losses in walls and an increase of the efficiency and the exhaust enthalpy. Furthermore, the variability of the timing diagram contributes to decrease the losses by pumping in the partial loads and to increase the efficiency on a wide range of speed by one over power stroke of exhaust gases (cycle of Miller). We so hope that this article will arouse certain interest to study this concept of architecture of chamber very promising. REFERENCES [1] Edouard Bonnefous, French patent demand n°1301584, took in 2013, unpublished. [2] Kenneth K. Kuo, “Principles of combustion”, 1951. [3] Abdel-Gayed et al. (1984), Abdel-Gayed et Bradley (1989). [4] Groupement Scientifique Moteur, “La combustion dans les moteurs d’automobile”, Ed. Technip,

1991. [5] John B. Heywood, “Internal Combustion Engine Fundamentals”, 1988.


15

EXPERIMENTAL RESEARCH ON THE HYBRIDIZATION OF A ROAD VEHICLE

Dan Mihai DOGARIU*, Anghel CHIRU, Cristian Ioan LEAHU, Marius LAZAR

Transilvania University of Brașov, Str. Politehnicii Nr. 1, 500024, Brasov, Romania

(Received 9 December 2014; Revised 15 January 2015; Accepted 23 February 2015)

Abstract: The electrification of the powertrain is one of the best solutions in the quest for obtaining emissions within the even more narrow limits imposed by legislation, with no penalty to the dynamic performances of the vehicle. This article describes a study regarding the possibilities of hybridization of a road vehicle. Based on real life situations, the custom driving cycles have been defined by means of GPS tracking. These driving patterns were further used in a simulation environment to test various configurations of classical and hybrid powertrains. The performances of the vehicle before and after hybridization were compared pursuing the change in emissions and fuel consumption. Keywords: driving cycle, driving simulation, engine emissions, GPS logging, hybrid vehicle

1. INTRODUCTION

The notion of hybrid vehicle is not new. At the beginnings of the automotive industry, the electric vehicle was more popular than the conventional vehicle, equipped with an internal combustion engine, which became common nowadays. The hybrid vehicle combines at least two different sources of power in order to provide traction to the wheels [1]. The sources of power can be very diverse, especially with the today’s technology. However, in vehicle dynamics, the most common and successful associations of power sources used up to now imply at least one electric motor and a thermal engine, mainly an internal combustion engine, but there are no limitations to use even an external combustion engine. One of the main advantages of using electrical propulsion is that it offers an ideal traction characteristic, high flexibility, and it simplifies the currently used driveline [1]. It is its relatively moderate range and high maintenance costs that limits its use only to industrial applications and city vehicles. On the other hand, the automotive industry turns back to electrification, in order to reduce the fuel consumption and emissions, to fit within the legal limits [3]. While all hybrid vehicles, which are mass produced, use electrical machines to assist the conventional CI (compression ignition) or PI (positive ignition) engine, a special attention to the exhaust gas after treatment must be paid. For example, shorter engine running periods will lead to little time for the catalytic converter to warm up, which in turn will decrease its conversion efficiency [3]. In this paper, the chosen powertrain configuration is the series hybrid, as seen in (Figure 1), in which the internal combustion engine is not directly, by mechanical means, linked to the driving wheels.

Figure 1. The powertrain configuration of a series hybrid



16

Since the thermal engine is used as a prime mover, to generate electrical energy with the help of a generator, and is not directly involved in the traction of the wheels, it may operate at a constant high thermal efficiency regime, thus improving the fuel consumption [1]. Moreover, by means of power electronics, a fraction of the braking energy may be recovered during the regenerative braking process. The advantages of using entirely electric traction at the wheels over the classical propulsion are best observed while driving in the city, where the stops and goes are numerous. It is here, where the constant or even no operation of the thermal engine contributes to a low level of emissions. Official comparisons, regarding emissions and fuel consumption, of vehicle performances are made after testing the vehicles according a standardized driving cycle, such as the NEDC (New European Driving Cycle) [1]. The complexity of the study consists in defining a custom driving cycle, by direct measurements on the road vehicle in traffic. The custom drive cycle regards a real life situation, which, at first, seems to be appropriate for using a hybrid vehicle. The measured results were further implemented in powertrain simulation software, where both the hybrid version of the vehicle and the vehicle itself were tested. The paper is comparing the two solutions considering the influence of the driving performances on the overall fuel consumption and emissions. 2. DRIVING CYCLE MEASUREMENTS

The driving cycle is a pattern of driving a road vehicle. This pattern is plotted in a speed vs. time graph. The custom driving cycle was defined on a commuting route, starting from a residential area and ending at a production plant just outside the borders of the city. Obviously, the reverse route was also considered. There have been recorded several driving cycles, but the one presented in this paper is the most demanding one, being recorded during rush hour and on the reverse track, that is from the outskirts of town towards downtown. The main characteristics of the custom track are described in (Table 1) and the conditions during measurements in (Table 2).

Table 1 Characteristics of the proposed driving cycle

Overall length 7.7 km Maximum speed 65 km/h

Average speed 30 km/h Time 910 s

For a modern vehicle equipped with a complex after treatment system a distance of less than 10 km is insufficient to assure its required working parameters [3].

Table 2 Initial conditions during measurements

Ambient temperature

22 – 25 ºC

Air pressure 748 mmHG

Elevation 680 m Road pitch < 0.1 % (neglected)

The measurements of the driving cycle have been realized directly on the vehicle, while driving in real traffic conditions towards the destination. The performances of the used vehicle are similar to the virtual vehicles used in simulations. The devices used for measuring the driving cycle are presented in (Figure 2). The GPS and the smartphone have recorded simultaneously the data concerning the track followed by the vehicle, while the GPS Antenna allowed real time streaming of the recorded data to the netbook via Bluetooth communication. The information sent to the netbook was saved in a typical GPS logging file, of NMEA protocol. The NMEA logging file contains the relative distance between two points, of which position was acquired at precise and narrow time intervals, of 0.1 seconds.


17

These values offered the possibility of plotting the evolution of the velocity of the vehicle in time, after a simple post processing. In this way, the driving cycle was obtained, which can be observed in (Figure 3).

Figure 2. Devices used to measure the drive cycle Figure 3. Measured drive cycle The data acquisition diagram accordingly to the measurement process used and to the further steps involved is presented in (Figure 4). Comparing to the NEDC (Figure 5), in this cycle, the vehicle starts directly on the fast lane, with the engine still cold. The number of idling periods is smaller in the proposed cycle; however the short trip may affect the functioning of the auxiliary devices of a hybrid vehicle.

Figure 4. Data acquisition diagram Figure 5. Comparing the custom driving cycle and NEDC With the help of special tracking software (GPS TrackMaker), the position of the vehicle may be visualized on a virtual map. The software specialized for GPS tracking are offering the possibility to export the saved information into several, more appropriate file extension, such that the track can be superimposed over a digital map. However, the most important export feature of this software is the connection file for MatLab, where the simulation was done. The MatLab version of the file allows the graphical representation of the driving cycle, as seen in (Figure 3) and (Figure 4), but also saving the measured data into the database of the powertrain simulation software, which is running under Matlab. 3. SIMULATING THE PROPOSED VEHICLES ON THE CUSTOM DRIVING CYCLES

The powertrain simulation software uses the driving cycle as requirement for the designed vehicle and tests it accordingly in order to estimate fuel consumption and emissions. The main features of the simulation software are:

� Estimation of the fuel consumption; � Estimation on the use and loss of energy for conventional, electric or hybrid vehicles; � Comparison between the emissions resulted after a number of cycles; � Optimization of the transmission ratios for reducing fuel consumption or improving the dynamic performances.


18

The main steps for a powertrain simulation under the Advisor (ADvance VehIcle SimulatOR) software are the following: Step 1 – Defining the vehicle; Step 2 – Defining the case study, initial conditions, and running the simulation; Step 3 – Visualization of the results. At first, a conventional vehicle was simulated, for a comparison reference. According to the steps mentioned above, the first step of the simulation is defining the vehicle. Figure 6 shows the configuration of the vehicle. Table 3 describes the characteristics of the chosen classical vehicle for testing.

Table 3 Characteristics of the tested classical vehicle

Figure 6. The conventional vehicle The definition of the vehicle includes the rated power, engine efficiency, engine map, and weight, along with the running accessories, such as air conditioning, headlights, radio, heated seats, wipers, and other custom loads, which may be easily defined. The reason for choosing a PI, positive ignition, engine are the light weight, compact after treatment, silent running, and it matches to the vehicle used to record the driving conditions [2]. The next step is choosing the driving regime, as shown in (Figure 7). In order to test the vehicle for a longer period of time, the driving cycle may be composed out of several predefined cycles from the internal database, or simply multiplied as required. In this case, a closed loop may be repeated as many times as it would be necessary. The results of the conventional vehicle (Figure 8) on the simulated track show the velocity of the vehicle, which is important to verify if the vehicle could follow the driving cycle, the exhaust gas temperature, which is important for the efficiency of the catalytic converter, emissions, and brake loss power. Figure 7. The initial conditions and simulation running Figure 8. The results of the simulation of the conventional vehicle

Pn Rated power of the thermal engine, PI

30 kW

nn Rated speed 6000 rpm MM Maximum torque 58.5 Nm nM Speed at maximum

torque 3300 rpm

mt Estimated mass 992 kg


19

The velocity of the tested vehicle is plotted in the first window and show that there is a small difference between the achieved speed and the one imposed by the cycle. The second plot shows the evolution of the exhaust gas temperature. It is very important for the temperature of the gas exiting the catalytic converter to be high enough, at least 600 ºC, for a high efficiency of conversion [3]. The graph shows that the necessary temperature of a good conversion is barely obtained at half of the route, which may damage the converter, but certainly have a negative impact on the environment. The third graph shows the evolution of the formation of the emissions, consisting of unburned hydrocarbons, CO, NOx, and PM. According to the graph, the emissions are reduced as the temperature of the catalytic converter is increased. The NOx emissions are increasing as the acceleration of the vehicle increases. The last plot shows the power lost during braking. The model of the series hybrid vehicle (Figure 9) is defined similarly as the conventional one. Table 4 describes the characteristics of the chosen hybrid.

Table 4 Characteristics of the proposed hybrid

Figure 9. The model of the series hybrid vehicle Preliminary results have shown that since the short distance of the proposed track, the analysis of the hybrid vehicle is not conclusive. The vehicle has reached its destination without turning on the combustion engine. For this reason, the test cycle has been multiplied by five, as shown in (Figure 10). In the first graph, the pattern with the driving cycle can be easily recognized, as it is repeated. The second plot is showing the evolution of the state of charge of the battery over the driving cycle. The battery is 70 % charged at the beginning of the ride and it depletes almost at the middle of the second cycle. The hybrid vehicle was design to start charging the battery when they reach approximately 30% charge. The generator maintains the state of charge of the batteries within certain limits according to a complex battery management, having the purpose to extend battery life [1]. The last plot gives information about the operation of the internal combustion engines, which turns on eight times, in order to keep the battery above 40% charged. Comparative testing (Figure 11) has shown that the hybrid vehicle reaches destination without the need for prime mover, a good situation if one could recharge from the grid. 4. CONCLUSION

According to the simulation of the chosen hybrid vehicle, it has been proven that a fuel converter with a power of 30 kW is sufficient to maintain the batteries within a functional domain, during a relatively common driving route, although the traction motors sums up a higher power. The remaining problem is the maintaining of the catalytic converter at a high temperature, even considering the stop-start strategy of the fuel converter.

Pn Rated power of the thermal engine, PI

30 kW

PM Rated power of the electrical machine

60 kW

PMg Power of the electrical generator

25 kW

PMb Peak power of the batteries

25 kW

SOC

Initial state of charge of the batteries

70 %

mb Estimated mass of the batteries

90 kg

mt Estimated mass 1120 kg


20

Figure 10. The results of the simulation of the series Figure 11. The comparative results of the series hybrid hybrid vehicle on five drive cycles vehicle and conventional vehicle on five driving cycles ACKNOWLEDGMENT

1. This paper is supported by the Sectoral Operational Programme Human Resources Development (SOP HRD), financed from the European Social Fund and by the Romanian Government under the project number POSDRU/159/1.5/S/134378. 2. We hereby acknowledge the structural founds project PRO-DD (POS-CCE, O.2.2.1., ID 123, SMIS 2637, ctr. No 11/2009) for providing the infrastructure used in this work. REFERENCES

[1] R. Hodkinson, J. Fenton, Lightweight Electric/Hybrid Vehicle Design. Butterworth-Heinemann, pp. 15-64, ISBN 0 7506 5092 3, 2001. [2] Websource: Energy density. http://en.wikipedia.org/wiki/Energy_density. [3] L. Hill, Emissions Legislation Review, proceedings of the conference Personalities of the Automotive Industry, unpublished, Brașov, 2013.


21

PRESENTATION OF A WHEEL LOADER WITH AN ELECTRIC DRIVEN PUMP AND WITH

ELECTRIC WHEEL DRIVES

Michael BUTSCH*, Uwe KOSIEDOWSKI, Peter KUCHAR, Manfred MACK, Dimitri ZIMANTOVSKI

Konstanz University of Applied Sciences, Brauneggerstraße 55, 78462 Konstanz, Germany

(Received 2 July 2014; Revised 15 September 2014; Accepted 1 October 2014)

Abstract: A new electric drive-train using the example of a small wheel loader will be presented and shows how the diesel engine and the hydraulic wheel drives can be replaced by electric driven wheel drives. Target is the reduction of emissions. Selective measures in order to reduce the noise of the hydraulic pump are necessary. As well the axles with regard to the installation of the electric wheel drives and an electromechanical steering were redesigned. The lithium ion battery is used as a counter weight in the wheel loader. Tests could be performed with a prototype. In comparison to the series wheel loader an essential noise reduction and a similar performance could be achieved. Keywords: wheel loader, electric drive, low emission, NVH, electromechanical steering

1. INTRODUCTION

Legal regulations with regard to emissions have become very tough for commercial vehicles. A new electric drivetrain using the example of a small wheel loader will be presented and shows how the diesel engine and the hydraulic wheel drives can be replaced by electric wheel drives. The newly developed synchronous electric motors combined with 2-stage planetary gears are battery-supplied. The lithium ion battery is used as a counter weight in the wheel loader. A prototype was built up with the help of a producer of commercial vehicles. The advantages of the electric drive are better acceleration, reduced cycle times and zero emission. Zero emission is necessary when working inside. As well the noiseless drive is an important advantage in housing zones. Because of the missing noise of the diesel engine the noise of the pump could be heard in an inconvenient manner. Systematic investigation made it possible to find means in order to reduce noise emissions to an agreeable level. Hydraulic drives only need small installation space while electric drives are larger. This made a new design of the axle necessary. The new design with optimizations of the structure and as well of the bearing positioning now even allows higher wheel loads in comparison to the series vehicle. An electromechanical steering system which has high efficiency will be used instead of the hydraulic system. The drive motors support the steering. For the closed loop control rotary encoders which are directly mounted at the steering axle are essential. 2. SYSTEM

The diesel engine, the tank for the diesel fuel and the hydro motors are replaced by electric motors and a lithium ion battery. The wheel drive at all four wheels are made of brushless synchronous disc motors in combination with 2-stage planetary gear sets. The oil pump which provides the hydraulic pressure for lifting the bucket and bucking off as well is driven by an electric motor of the same type. The hydraulic steering is going to be replaced by an electromechanical steering. Figure 1 [1] shows the electric and electronic structure of the electric wheel loader. The main microcomputer controls the AC controllers of the wheel drives. If it is necessary the cooling of the controllers and wheel drives is activated. The driver operates the bucket with a control stick. There are two pedals – one for accelerating and one for braking. Acceleration and braking are operated “by wire”. Braking is realized by the electric motors and in addition



22

with a disc brake at two of the wheel drives. The lithium-ion battery (LiFeYPO4) has a capacity of 21.4 kWh, a voltage of 70.4 V and a mass of 211.4 kg. In the trunk of the wheel loader the diesel engine and one pump are replaced by the battery. The battery has also the function of the counter weight. A controlled charging of the battery is besides an adequate cooling very important. Each cell has to be monitored with regard to voltage and temperature while being charged.

Figure 1. Electric and electronic structure [1]

3. HYDRO PUMP AND NOISE REDUCTION

Disc motor and hydro pump are placed under the seat of the driver. In a wheel loader which is driven by a diesel engine the noise emissions of the pump are considerably less than those of the engine. Having electric motors the noise emissions of the motors are very low and the series pump (Sauer Danfoss SNP2) is too noisy. The calm running pump of Rexroth Company (series S) offers a sufficient reduction of the noise level. The results of the noise measurements are shown in Figure 2.

Figure 2. Noise emissions of different types of pumps [2]

noise level dB(A)

70 65 60

speed [min-1]


23

4. REDESIGN OF THE AXLES The complete wheel drive is mounted in the steering knuckle. The wheel drive consists of a disc brake, a resolver, an electric motor and a planetary gear. This device is larger than a hydro motor which results in a redesign of the axles (Figure 3 [3]). The axles are optimized with regard to strength by using the method of finite elements (Figure 3, b [4]).

v

Figure 3. Redesign of the axle [3][4]

A special assembly of the slide bearings with a locating bearing at the bottom and a combination of a radial and an axial bearing at the top make sure that both crossbeams of the axles are strained by the weight of the wheel loader (Figure 3, d). In the upper knuckle pin a rotary encoder in integrated. The steer angle of each wheel can be measured.

5. ELECTROMECHANICAL STEERING

So far the wheel loader has a hydraulic steering. Target is the development of an efficient electromechanical power steering for wheel loaders. Electromechanical steering is often used in passenger cars in terms of efficiency. Figure 4 shows the design for the wheel loader with an electric motor, a belt drive and a screw drive [3]. Torque vectoring can be realized because of the wheel drives. The traction forces of the electric motors can be used for the support of the mechanic steering.

6. RESEARCH RESULTS

A significant reduction of noise emissions can be realized by the replacement of the Diesel engine and by using a quiet pump. Very important in respect to the practical use of an electric wheel loader are the capacity of the battery and the acceleration of the wheel loader. Comparative investigations of the series wheel loader and the new electric wheel loader are performed. The so called “Y-cycle” is used for the test drives [5]. The cycle is shown in Figure 5 at the top on the right.

Legend 1 – axle with two crossbeams 2 – stearing links 3 – wheel drive 4 – encoder 5 – knuckle 6 – bearing

1 2

a

3

c

b

4

6

5

d


24

Figure 4. Electromechanical Steering [3] Figure 5. Electromechanical Steering [5] The wheel loader forwards empty, takes the load (480 kg), drives backwards with lifted bucket and then goes forwards again in order to buck off the load. An average of 25 tests performing the Y-cycle and additional endurance tests show the following results:

- the capacity of the battery is sufficient for an eight hours workday. - despite of the control of the prototype, which couldn´t be optimized so far, the duration of the

cycles performed with the electric wheel loader are similar to those of the series wheel loader. Figure 5 shows details of the tests. The electric wheel loader is faster than the series wheel loader when driving with load backwards but because of traction problems slower when driving forwards. An improvement of the control is necessary.

7. CONCLUSION The concept of a totally electrified wheel loader could be realized with a prototype. The targets with regard to the reduction of the noise emissions, the capacity of the battery and the dynamic of the wheel loader could be achieved. REFERENCES

[1] Butsch, M.; Kosiedowski, U.; Mack, Manfred; Zimantovski, D., Developing an Electric Powertrain for 4WD Commercial Vehicles. Electric & hybrid vehicle technology conference, Novi, Michigan, 2013. [2] Kosiedowski, U.; Butsch, M.; Kuchar, P.; Zimantovski, D.; Hydrauliksystem eines Elektroradladers. Forum – Das Forschungsmagazin der Hochschule Konstanz. ISSN 1619-9812, Konstanz, Ausgabe 2012/ 2013. [3] Koch, M.; Butsch, M., Unpublished project work. Konstanz, 2013. [4] Belhadj, M; Butsch, M., Unpublished project work. Konstanz, 2013. [5] Beck, Hermann: Emissionsreduzierung durch Antriebsstrangoptimierung. Dresden. Fachtagung Baumaschinentechnik, p. 145, 2009.


25

GLOBALIZATION OF THE AUTOMOTIVE INDUSTRY – FOCUS ON GERMAN AUTOMOTIVE MANUFACTURER'S

Vijay NARAYANAN1)*, Axel MAURER2, Lucian RAD3

1) Hella India Lighting Ltd. 6th Floor, Platinum Tower, 184 Udyog Vihar Phase-1Gurgaon 122016 (Haryana) India

2) Webasto Roof & Components SE, Kraillinger Straße 5 82131 Stockdorf Germany 3) Transilvania University Brasov, Str. Politehnicii nr. 1 500024 Brasov Romania

(Received 9 January 2015; Revised 2 February 2015; Accepted 28 February 2015)

Abstract: The reduction in international barriers is accelerating the rate of Globalization in the automotive industry. Internationalization in the form having production facilities on a global foot print is on an increasing trend, especially among the German automotive manufacturers. This development is important to understand at the international stage as along with the OEMs, their suppliers (primarily German Tier 1) are also increasing their global presence. This implies that the production standards, requirements and specifications have to be standardized worldwide not only for OEMs but also system and sub-system manufacturers. Parts also have to meet legal requirements of individual production locations thus creating a fascinating spread of knowledge and technological advancements worldwide. Key-Words: Globalization, German Automotive, Passenger Car.

1. WHAT IS GLOBALIZATION? The term Globalization represents expansion into the world markets with economic dependence, becoming more of international phenomena than restricted to a particular country or region. Globalization can be attributed to developing countries, still being underdeveloped, provides a cost benefit to the manufacturing firms and a systematic breakdown of the labor unions. Globalization comes with its advantages and threats for both the industry and the developing countries in the world. Technological advancements have increased; have broken barriers and increased fast modes of communications across the world. The internet, email, telephone and fax allow faster mode of communication channels that provide instant communication. Through logistical advancements, exchange of goods and services are possible between most countries in the world. This advancement is not only limited to the manufacturing segment. With tourism becoming global phenomena, interactions between the different cultures are happening at a faster rate. The cultural barriers are broken and increases intercultural competence. The globalization in its current form can be best summarized in this from as depicted in figure 2 [1]. In the automotive industry, globalization is relevant for almost a century with examples like the manufacturing of Chevrolet passenger cars in India in the early part of the nineteenth century. Mass production as a volume game and manufacturing through suppliers are more of recent developments in the global automotive manufacturing. Until the 1970s, the focus of automotive manufacturing was centered on the Triad regions namely North America, Europe and Japan. The beginning of the 1980s saw a shift in this trend with manufacturing moving towards emerging markets in Asia. The decade starting from 1981 saw automotive manufacturing emerge in Thailand, Malaysia, Philippines and South Korea. This period was considered the first wave of automotive globalization. This period saw more manufacturing investment in Asia rather than China, South America and Eastern Europe. The second wave of automotive globalization was the period from 1990 to 2000. During the second wave much larger investments were made in China, South America and Europe. The third wave beginning from 2000 saw much more investments made in China and Eastern Europe with drop in investments in Asia, South America and Western Europe [2].



26

A recent trend seen as an effect of globalization is the formation of strategic alliance formation among auto majors such that they could harness each other’s synergies. One such example is the alliance between Nissan and Renault. The alliance is moving towards a Common Module Family (CMF) which apart of other benefits will provide a common pool of parts for small vehicles and a common platform for a range of product portfolio [5]. The globalization phenomena are equally important for the automotive supplier pool. A recent study by Oliver Wyman showed that globalization is the fourth important criteria for success behind customer orientation, entrepreneurial action and cost position [6].

Figure 2. Links between the factors of globalisation [4] The globalization of the automotive industry is predominantly driven be technological advancements. This has led to formation of commercial blocks that changing the formation of global markets. These commercial blocks also have a political relevance. For example, the case of the European Union shows such formations by reduction of internal commercial restrictions, protects its internal market, dictates new market rules and controls the global economic power. The other players in the market follow the same concepts and build power blocks of their own like the NAFTA (formed by the United States of America, Canada and Mexico), MERCOSUR (formed by the South American countries), ASIAN (formed by Asian countries including Japan). These power blocks of economic and commercial importance can be represented as follows [3]. 2. WORLD WIDE PASSENGER CAR PRODUCTION 2012-2013 Figure 3 best describes the bifercation of the passenger car production world wide. Asia dominates the world market with close to half of the produced numbers wih Europe, NAFTA and MERCOSUR being distant followers. The rest of the world contributes a meger 3% to the production volumes. It is evident from the data that production volumes grew marginally in Europe by 0.2% compared to NAFTA, MERCOSUR and Asia which grew by 4.5%, 7.5% and 9.3%. The growth in production volumes in lesser developed economics indicates the effect of Global players penetrating local markets.

„Globalization does not begin with the export numbers, it begins in the minds of managers“

Roland Berger,

German Industry Consultant

Figure 1. German Automotive Manufacturers

Worldwide environmental

pollution

Worldwide communication

Worldwide interchange of goods, services and capital

Worldwide tourism

Worldwide intercultural exchange


27

Asia and MERCOSUR together contribute 52% of the global production volumes indicating a strong growth in the developing economies of Brazil, India and China where global OEMs benefit from highly skilled but low cost work force.

Table 1 Production Locations of OEMs based on Maurer [3]

EU – 15 EU

New Members EASTERN EUROPE MERCOSUR NAFTA ASIA

Austria Belgium Finland France Germany Great Britain Italy Netherlands Portugal Spain Sweden

Czech Republic Hungary Poland Romania Slovenia Slowakia

Belarus Rusia Serbia & Montenegro Turkey Ukraine

Argentina Brasil

Canada Mexiko USA

China India Indonesia Japan Malaysia South Korea Taiwan Thailand

Table 2 World passenger car production2012-2013 [7]

Region 2012 2013 %

Change

Europe 17,246,660 17,289,262 0.2

NAFTA 15,380,715 16,074,821 4.5

MERCOSUR 3,976,388 4,274,164 7.5

Asia 31,658,791 34,612,331 9.3

Rest of the World

2,250,000 2,250,000 0.0

Total 70,512,554 74,500,578 5.7

Figure 3. World Wide Car Production 3. PRODUCTION VOLUMES OF GERMAN PASSENGER CAR MANUFACTURERS It is evident from the production volumes of 2012 and 2013 that the German branded car volumes are on an increasing trend. German passenger car worldwide production volume dominates the domestic market production as explained by table 3. The overall growth is about 3% with overseas production showing signs of strong growth. It is interesting to note that the car production in the domestic market grew by 1% compared to the increase in production volumes abroad by 5%. The penetration of the German carmakers in the global market confirms the effect of Globalization benefits derived from production locations in developing economies. A study by KPMG in 2008-2009 classified countries based on automotive suppliers globalization which put both German and American automotive suppliers with the same globalization index based on

location at about 78.5% each. Western Europe excluding Germany was at 90.2% and Asia with 76.1% was less represented in the global footprint among automotive suppliers [10].


28

Table 3 Production volumes of German passenger

car manufacturers [7 adapted]

German Car Manufacturers 2012 2013

% Change

Domestic Passenger Car

Production 5,388,459 5,439,904 1%

Abroad Passenger Car

Production 8,235,816 8,641,880 5%

Total 13,624,275 14,081,784 3%

Figure 4. VW Group Sales volume 2012-2013 [9] 4. CONCLUSIONS The production volumes worldwide show that developing economies are taking the lead in passenger car production. The increase in German brand production outside Germany also indicates that German Car OEMS are maximizing the effect of globalization. This trend will have some interesting side effects. The quality requirements in the emerging markets would increase by leaps and bounds and would benefit local Tier 2 and Tier 3 who normally would not have access to such high end product and process knowledge. Also the availability of highly skilled low cost labour will help in reducing the overall process cost of the product. ACKNOWLEDGEMENT This work was partially supported by the strategic grant POSDRU/159/1.5/S/137070 (2014) of the Ministry of National Education, Romania, co-financed by the European Social Fund – Investing in People, within the Sectorial Operational Programme Human Resources Development 2007-2013. REFERENCES [1] Hund, J., „Globalisierung“, IWB Radolfzell e.V. [2] Maurer, A., „The new focus of globalisation in the Automotive Industry“, Scientific Bulletin Automotive Series, year XIII, No. 1. [3] Maurer, A., “Effects of the financial crisis on the global automotive industry”, Ingineria Automobilului, Society of Automotive Engineers of Romania (SIAR) 4/2009. [4] Maurer, A., “Forschungen zur Optimierung der Produktion von Komponenten für die Automobilindustrie unter den Voraussetzungen der Globalisierung”, Dissertation, Universitatea Transilvania Brasov, 2015. [5] Oagana, A., „Renault-Nissan Alliance to Switch to Just Three Modular Platforms”, http://www.carscoops.com/2014/07/renault-nissan-alliance-to-switch-to.html. [6] Wymann, O., „Herausforderung Globalisierung“, Oliver Wymann GmbH, München 2015. [7] Verband der Deutschen Automobilindustrie (VDA).

[8] Volkswagen AG, http://www.volkswagenag.com/content/vwcorp/info_center/en/publications/2014/03

/navigator_2014.bin.html/binarystorageitem/file/NAVIGATOR_ENGL_WEB_01_08_14.pdf. [9] Volkswagen AG, http://www.volkswagenag.com/content/vwcorp/content/en/the_group/ key_figures.html#field1=maincategory_0,field2=subcategory_1.


29

RESEARCH REGARDING THE INFLUENCE OF BIOFUELS ON THE LAW OF HEAT RELEASE FROM A DIESEL ENGINE

Bogdan BENEA *, Anghel CHIRU, Gabriel MITROI

Transilvania University Brasov, Str. Politehnicii nr. 1 500024 Brasov Romania

(Received 17 December 2014; Revised 12 February 2015; Accepted 27 February 2015)

Abstract: This paper aims to research the influence of physic-chemical properties of biofuels on the law of heat release on Diesel engine. The research has been conducted on a Renault K9K-P732 series engine fueled with biodiesel from sunflower, peanut, grape seed, palm, corn, olive oil and waste oil, in concentrations of 6% and 10%. Key-Words: bio-fuels, renewable energy, Diesel engine.

1. INTRODUCTION

Internal combustion engines will continue to dominate transport technology using liquid fuels produced from fossil and renewable sources. Biofuels are the best option for replacing the fossil fuels [5]. Directive 2009/28 / EC require the use of 10% biofuels in fossil fuels for transport by 2020. Is expected to use about 18% of European agricultural land to produce biofuel crops needed to replace fossil fuels in accordance with Directive 2009/28 / EC [5]. The provisions of Directive impose requirements in terms of quality and chemical composition of these. High oil price make biofuels and synthetic fuels an economically viable alternative. Alternative energy sources must be found to cope with increased demand for energy in all areas. In this context, the additions of fuels with biofuels or second generation synthetic fuels constitute a course of action for the future. Another way may be to develop new sources of energy, clean. 2. TESTS AND RESULTS The tests were made on an engine K9K Renault P 732 series having the characteristics presented in Table 1.

Table 1 Characteristics engine Renault K9KP732

Engine displacement 1451 cm3

Bore x stroke 76 x 80,5 mm

No. of cylinders 4/line/supercharged

Order of injection 1-3-4-2

Injection type Direct injection, common-rail

Compression ratio 15,3:1

Number of valves/cylinder 2

Maximum power 78 kW/4000 rot/min

Maximum torque 240 Nm/2000 rot/min

Emission class Euro4

Tests were conducted on engine test bench Horiba Titan 250, which is fitted as Transilvania University of Brasov, Faculty of Mechanical Engineering, Vehicles and Transport Department, presented in Figure 1. The stand is equipped with an electric brake that is designed to oppose of the crankshaft rotation. During operation appears an electromagnetic field that links the stator and rotor brake.



30

Figure 1. Horiba engine test bench Titan 250 The advantage of electric brake is the possibility of instantaneous changing of the electromagnetic coupling. For measuring the cylinder pressure was used a Kistler 6005 piezoelectric sensor (figure 2); the sensor characteristics is presented in table 2

Table 2 Characteristics of Kistler sensor [1]

Range 0 – 1000 bar

Sensitivity -10 pC

Linearity ≤ ±0,8 FSO

Natural frequency 140 kHz

Operating temperature -196 – 200oC

Figure 2 Pressure sensor The operating principle of this sensor is based on the fact that by the compression of the quartz crystal it is charged with electrical load. Electrical load, measured in pC, is directly proportional with the pressure applied. By assessment of the electrical load can determine the value of pressure (instantly). The tests have been made for 15 fuels (biodiesel with diesel fuel, gas oil mixed with 6% and 10% methyl ester of olive oil, grape seed oil, palm oil, peanut oil, corn oil, sunflower oil, cooking oil used). Methyl esters were synthesized according to the conventional equation for the transesterification of vegetable oils in the presence of methanol using KOH as a catalyst. The transesterification took place in the following standard conditions: reaction temperature 60 ° C, pressure 1 bar, the ratio methanol / vegetable oil 6: 1, 1% of potassium hydroxide, mixing speed 550 rev / min, 120 min of reaction time. In table 3 are presented the characteristics of fuels used in the tests. Tests were performed at maximum engine power speed (3700 r / min) and a load of 100%. The modern fuel injection injected volumetric the fuel into the cylinder. Because the density of biodiesel blends is higher than the density of diesel fuel, the mass of fuel injected into the cylinder is higher, which offset the lower calorific value of biodiesel blend.


31

All biodiesel blends have higher cetane number than diesel, which leads to lower delays of self-ignition and smaller opportunities to form areas with rich mixture.

Table 3. Physico-chemicals properties of fuels

Properties Density (20oC) [kg/m3]

Viscozity (20oC) [mm2/s]

Cetanice number

Flash point [oC]

Aromatics [% vol]

Poly- aromatics [% vol]

Heating value [MJ/kg]

Pour point [oC]

Diesel fuel 840,2 5,34 51,1 67 17,6 1,5 43,16 -17

B6 841,9 5,27 54,5 67,2 11,9 1,2 42,58 -14 Sunflower oil B10 843,1 5,10 57,6 67,8 5 0 42,19 -13

B6 841,3 5,12 59,2 69,5 12,3 0,1 42,60 -14 Olive oil B10 842 5,21 63,8 71,8 11,3 0 42,22 -13

B6 841,7 5,04 57,6 71,4 11,2 0 42,63 -16 Corn oil B10 842,7 4,99 62,1 67,3 7,9 0 42,27 -15

B6 842,1 5,12 57,8 70,6 13,2 0,3 42,59 -11 Peanut oil

B10 843,4 5,94 60,9 70,2 9 0 42,20 -8

B6 842,1 5,25 58,3 76,6 12,9 0 42,58 -10 Palm oil B10 843,4 5,32 62,7 73,4 9,2 0 42,19 -8

B6 841,6 4,93 57,7 71,2 14,8 0,2 42,51 -14 Grape seed oil B10 843,4 5,10 62,5 73,4 8,1 0 42,07 -13

B6 842,7 5,27 54,2 70,8 9,1 0,8 42,56 -14 Used oil B10 844,4 6,15 58,9 71,2 10,5 0,9 42,19 -13

Figure 3, a. Heat release variation (6%)


32

Figure 3, b. Heat release variation (10%) Looking at Figure 3 it appears that B6 olive and B10 corn mixture have a high heat release in the first phase of combustion, and in the second phase the amount of heat released is lower, helping to reduce NOx emissions 3. CONCLUSIONS Since fuel reserves are limited, fuel price is high, the environment must be protected from emissions of internal combustion engines, they did research to find alternative resources. Biodiesel may be mixed with the diesel fuel in a proportion of up to 20% without any change of the supply system of the engine. Calorific value of biodiesel is lower than of diesel fuel, but has better qualities of auto-ignition (higher cetane number). By increasing the cetane number is reduced the auto-ignition delay and obtain a lower growth rate of pressure, which leads to higher cooling time of combustion. Due to lack of polyaromatic and aromatic hydrocarbons in biodiesel the flame temperature is lower. Biodiesel with high saturation level and higher cetane number have lower NOx emissions. REFERENCES [1] AVL – Engine instrumentation, Cooling system ZP91: Austria, September, 2002 [2] AVL – ICE Physics & Chemistry Manual, 2010 [3] AVL – Microifem Multipurpose module 4FM2: Austria, January 2006 [4] Benea, B.C, Researches on the usage of biofuels for car engines – PhD Thesis [5] BIOFRAC, B.R.A. Council, „Biofuels in the European Union: A Vision for 2030 and Beyond”, European Communities, Report 13, 2006 [6] EEA, Air quality în Europe – 2012 report, European Environment Agency, 2012 [7] Ekrem, B., Effects of biodiesel on a DI diesel engine performance, emission and combustion characteristics, Fuel, vol. 89(10), pag. 3099-3105, 2010

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Societatea Inginerilor de Automobile din România Society of Automotive Engineers of Romania

www.siar.ro www.ro-jae.ro

ISSN ____ – ____ (Online, English) ISSN 1842 – 4074 (Print, Online, Romanian)

The Scientific Journal of SIAR A Short History

The engineering of vehicles represents the engine of the global development of the economy. SIAR tracks the progress of the automotive engineering in Romania by: the development of automotive engineering, the development of technologies, and road transport services; supporting the work of the haulers, supporting the technical inspection and of the garage; encouraging young people to have a career in the automotive engineering and road haulage; stimulation and coordination of activities that promote an environment that is suitable for continuous education and improving of knowledge of the engineers; active exchange of ideas and experience, in particular for students, master students, PhD students, and young engineers, and dissemination of knowledge in the field of automotive engineering; cooperation with other technical and scientific organizations, employers’ and socio-professional associations through organization of joint actions, of mutual interest. By the accession to FISITA (International Federation of Automotive Engineering Societies) since its establishment, SIAR has been involved in achieving an overall professional community that is homogeneous in competence and performance, interactive, dynamic, and competitive at the same time, oriented towards a balanced and friendly relationship between people and the environment; this action will be constituted as a challenge worthy of effort and recognition. The insurance of a favorable framework for the initiation and the development of cooperation of the specialists in this field of activity allows for an efficient and easy exchange of information, specific knowledge and experience; it supports the cooperation between universities and between research centers and industry; it speeds up the process of implementing the new technologies, it simplifies the identification of training and specialization needs of the personnel involved in the engineering of motor vehicles, transport, and road safety. In order to succeed, ever since its founding, SIAR has considered that the stress should be put on the production and distribution, at national and international level, of a publication of scientific quality. Under these circumstances, the development of the scientific magazine of SIAR had the following evolution: 1. RIA – Revista inginerilor de automobile (in English: Journal of Automotive Engineers) ISSN 1222 – 5142 Period of publication: 1990 – 2000 Format: print, Romanian

Frequency: Quarterly Electronic publication on: www.ro-jae.ro

Total number of issues: 30 Type: Open Access

The above constitutes series nr. 1 of SIAR scientific magazine.

2. Ingineria automobilului (in English: Automotive Engineering) ISSN 1842 – 4074

Period of publication: as of 2006 Format: print and online, Romanian

Frequency: Quarterly Electronic publication on: www.ingineria-automobilului.ro

Total number of issues: 33

(including the December 2014 issue)

Type: Open Access

The above constitutes series nr. 2 of SIAR (Romanian version).

3. Ingineria automobilului (in English: Automotive Engineering) ISSN 2284 – 5690

Period of publication: 2011 – 2014 Format: online, English

Frequency: Quarterly Electronic publication on: www.ingineria-automobilului.ro

Total number of issues: 16

(including the December 2014 issue)

Type: Open Access

The above constitutes series nr. 3 of SIAR (English version).

4. Romanian Journal of Automotive Engineering ISSN 2284 – 5690

Period of publication: from 2015 Format: online, English

Frequency: Quarterly Electronic publication on: www.ro-jae.ro

Total number of issues: 1 (March 2015) Type: Open Access

The above constitutes series nr. 4 of SIAR (English version).

Summary – on March 31st. 2015 Total of series: 4 Total years of publication: 21 (11=1990 – 2000; 10=2006-2015) Publication frequency: Quarterly Total issues published: 64 (Romanian), out of which, the last 17 were also published in English

Mars 2015 4 Number 1 - ingineria-automobilului.ro · RoJAE vol. 21 no. 1/ Mars 2015 ISSN ____ –...

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