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About this book

Wer die gesamte "Well-to-Wheel"-Kette betrachtet, stellt schnell fest: Der Verbrennungsmotor und seine Kraftstoffe sind auch heute nicht wegzudenken, wenn es gilt, Pkw und Nutzfahrzeuge anzutreiben. Die Erkenntnis, dass die Elektrifizierung der Fahrzeugantriebe sich nur evolutionär entwickeln kann, sichert dem Verbrennungsmotor weiterhin die Pole-Position als Schrittmacher in eine Mobilität mit geringen Schadstoffemissionen. So gilt es, vom Dreizylinder-Pkw- bis zum Achtzylinder-Nfz-Motor, neben verschiedenen technologischen Optimierungsmöglichkeiten, weitere verborgene Potenzial in den Bereichen Mechanik Ladungswechsel, Verbrennung, Abgasnachbehandlung und Wärmemanagement zu heben. Vor dem Hintergrund dieser Entwicklungsaufgaben veranstalten ATZlive und das VDI Wissensforum zum dritten Mal gemeinsam den Internationalen Motorenkongress.

Table of Contents




Keynote Lecture: Matter of character or pabulum? The role of IC engines in shaping next-generation powertrains

Nikolay Ardey, Geert Schmitz

Keynote Lecture: The challenge for fuels for the future

Wolfgang Warnecke

Keynote Lecture: Sustainable and increasingly efficient road transport for the next generations – continuous improvement through an integrated approach

Ron Borsboom

Passenger car and truck engines – a comparison from a thermodynamics point of view

Peter Eilts



3-motor HEV powertrain for super sport

• High power and low center of gravity in a compact layout• Total system peak output is 573 horsepower• High response powertrain that generates sufficient torque from low vehicle speeds and low rpms• 0 100 kph acceleration increased 21% with MOT assist• Acceleration from 30 to 100KPH improved 12%• Balance of cornering performance and high speed driving stability due to distribution of drive to front, rear, left and right

Hirokazu Toyoshima

Vehicle integration of a new engine concept for 48 Volts – opportunities for efficiency improvement and optimization of the overall system complexity

To achieve fleet fuel consumption legislation of 95g/km CO2 in 2020, various electrification measures will be introduced, besides engine measures, to reduce the overall energy demand of the vehicle. 48V architecture represents an attractive compromise between the standard 12V system and high voltage hybrid systems. The 48V system offers on the one hand already attractive performance potential for moderate hybridization steps, on the other hand, opportunities open up for the electrification of the internal combustion engine (ICE) and its auxiliaries as well as other vehicle components with high power demand. Current belt starter-generator systems already realise direct recuperation and torque boost functions. Additionally they can support a highly effective electrical supercharging system which is clearly superior to current multi-stage turbocharging concepts, particularly in transient response. With flywheel startergenerator concepts, additional functions open up such as purely electric driving in a limited range, or simplification of the base engine towards the goal of a beltless engine. Demand controlled, electrical auxiliaries are already in series production for the cooling-, vacuum- or air conditioning systems. Additional areas of interest are the oil system and variable elements in the valve train or crank train.AVL has discussed and compared the options on the base engine, as well as evaluated in terms of function, added value and system cost with the aim of minimizing overall system complexity through application-dependent balanced distribution of electrical and mechanical functions. The logical next step is the vehicle integration of this “ideal” base engine. Additional opportunities are opened up in regard of function and package by increased flexibility in the position of auxiliaries as well as function integration. Key is the overall system evaluation of the vehicle front section considering energy demand, cost, thermal management, aerodynamics and acoustics.

Helfried Sorger, Peter Schöggl, Wolfgang Schöffmann, Matthias Hütter, Thorsten Krenek, Gernot Fuckar, Jonathan Hood, Bernhard Graf



Heavily downsized gasoline demonstrator

Gasoline engine downsizing is already established as a proven technology to reduce automotive fleet CO2 emissions by as much as 25 %. Further benefits are possible through more aggressive downsizing, however, the trade-off between the CO2 reduction achieved and vehicle drive-ability limits the level of engine downsizing currently adopted.This paper will present results from a 48 V mild hybrid engine demonstrator, featuring an eSupercharger and belt integrated starter generator.The original 1.2 litre, 3-cylnder MAHLE downsizing engine has higher BMEP levels than any gasoline engine currently in series production. This engine has now been reconfigured to enable a very high specific power output to be achieved, in excess of 160 kW/litre, whilst retaining excellent drivability and fuel economy. Of key importance is a cost effective, efficient and flexible boosting system. An eSupercharger, operating at 48 V, enables the transient response and low speed torque to be more than recovered, enabling both very high specific output and specific torque characteristic with excellent transient response and drivability characteristics.In this application the eSupercharger is no longer simply a transient device, but also a key contributor to the steady state engine performance. It is therefore essential to the concept that there is a means for supplying the eSupercharger with sustained electrical power, if the steady-state torque output of the engine is to be maintained. The demonstrator vehicle features a 48 V belt integrated starter alternator (BiSG) and an advanced lead carbon battery pack.This paper demonstrates eSupercharging as a technology enabler for extreme engine downsizing, and discusses the compatibility with 48 V micro-hybridisation, for further CO2 emissions reduction. The energy management, and power flow, for controlling battery state of charge, minimising CO2 and maintaining good transient response will be presented.

Benjamin Hibberd, Mike Bassett, Jonathan Hall, Stephen Borman

Extreme downsizing for gasoline engines – fun to drive with extremely low emissions

This paper elaborates different boosting systems for extreme downsizing levels considering the target of optimal transient performance:• Turbocharger for 90 kW/l and 140 kW/l layout• Turbocharger (TC) and electric turbocompressor in three different layouts• Turbocharger supported by electric motor-generator unit (eTC) with and without FEV Dual Fresh Air Bypass (FEV Dual FAB)The performance benefits of the combination (TC+eC) are confirmed by FEV’s new high performance demonstrator vehicle and underline the fun-to-drive of such a concept.The addition of a 48 V eC enables improvement in time to torque between 23 % and 77 % depending on the investigated engine speed. Low-end-torque-speed can be (temporarily) shifted from engine speed of 2500 1/min to 2000 1/min. These outstanding results are based on an optimized matching of the TC and the eC, the performance of the eC unit itself and the model based ECU control. It could also be demonstrated that the favourable dimensions of the eC lead to an optimum package situation resulting in low pressure losses and therefore an optimized airpath concept.The introduction of an eTC yields great transient performance benefit especially at high engines speeds. Transient performance at low engine speeds as well as well lowend-torque is limited due to compressor surge. The addition of FEV’s Dual Fresh Air Bypass solves this drawback of the eTC in these operating conditions.

Tolga Uhlmann, Henning Baumgarten, Björn Franzke, Johannes Scharf, Matthias Thewes, Georg Birmes

Potential of air gap motors to realize electrically assisted turbocharging, Cross-Charger® – turbo by wire

Wie dargestellt wurde, ist auf Grund der hohen Leistungsdichte das Potenzial der Medienspaltmotoren zur Realisierung einer elektrisch unterstützten Aufladung sehr groß. Die erzielten motorischen Wirkungsgrade der elektrischen Komponenten sind absolut wettbewerbsfähig. Es konnte in diversen Kundenprojekten der Nachweis erbracht werden, dass der MSM auch im Cross-Charger® das entsprechende Leistungspotenzial besitzt, nahezu saugmotorische Agilität mit einem hoch aufgeladenen Verbrennungsmotor zu erzielen. Neben dem beschriebenen hohen Leistungspotenzial werden auch die Kosten- und Packaging-Vorteile der Cross-Charger®-Technologie dessen Marktdurchdringung forcieren.Nun gilt es, gemeinsam mit den Kunden und deren Zulieferindustrie den Reifegrad der Technologie so weiter voranzutreiben, dass ein zeitnaher Serieneinsatz ermöglicht wird.

Holger Gödeke, Ernst Knorpp, Christian Köster, Kurt Prevedel



Influencing factors on particle formation under real driving conditions

The future worldwide emission legislation is posing a challenge for the powertrain development especially in regards to emission reduction under real driving conditions. To achieve the targets a suitable development methodology, the usage of dynamic measurement equipment and simulation tools, as well as a detailed understanding of the physical phenomenon and mechanisms are essential. In the following example with a gasoline combustion process with direct injection and turbocharging APL Group presents an optimisation of particulate emission.

Christian Lensch-Franzen, Marcus Gohl, Tobias Mink, Martin Schäfer

System influence and requirements for monitoring diesel particulate filters without particulate matter sensors

In this study, the various influences on backpressure based DPF monitoring have been investigated. A number of inputs are influenced by tolerances that negatively affect measured pressure, modelled volume flow and modelled backpressure. A simulation has been performed to evaluate the influence of those tolerances on the final diagnostic robustness. For some of the tolerances, state-of-the-art tolerance values have been defined. Based on the simulation, upper limits were defined for the remaining tolerances. In a series application, if the defined tolerances can be met, a robust monitoring of a DPF using just the pressure sensor appears to be possible. In this case, no other monitoring strategy, e.g. a PM sensor, is needed.The defined numbers are assumed for vehicles with engine-out soot emissions around 40 mg/km. If above defined tolerances cannot be reached, it is helpful to reduce engine- out soot emissions. The correlation is roughly linear, at least if changes are not too large: A 20 % increase in tolerances must be countered by a 20 % decrease of raw emissions.The simulation has been performed using average DPF characteristics. For vehicles with different characteristics, e.g. higher or lower backpressure, the relative impact of the individual tolerances may change.

Holger Pieta, Matthias Kötter, Markus Netterscheid, Bernd Lindemann



Technologies for (pilot) injection quantity control in modern common rail diesel engines

Clean, powerful and efficient automobiles are the entry card into the automotive future. Unfortunately, simultaneously to the big progress in exhaust gas cleaning technology on the one side, more challenging testing cycles and also the focus on “customer usage conditions” do exist as challenging legal requirements on the other side. As a consequence, low engine out emissions still are important for the OEM and here the fuel injection system plays a substantial role.With the introduction of Common Rail technology the concept of “multiple injections” e.g. a mix of 1-5 pilot injections, up to 2 main injections and 1-3 post injections became a standard. Different to gasoline engines, were (global) λ-control covers a big portion of fuel injection control, diesel engines suffer from poor knowledge on the real injection pattern – that is the precise and physical correct split of the injections.

Johannes Ullrich, Roland Steininger, Viktor Boschmann, Bernd Friedrichs

Effect of diesel injector tip deposits on transient spray behavior

The structural characteristics of high pressure diesel sprays have been investigated using two different complementary techniques, and the impact of injector fouling on the spray development has been assessed. In the first novel technique, fuel was injected into a reservoir of water, a liquid that offered high density ambient conditions. In a second technique, fuel was injected into a pressurised constant volume chamber.The fuel spray cone angle from a fouled injector was found to increase by 10-140% when sprayed into water, as compared to the cone angle from a new injector. The presence of carbonaceous deposits accumulated during regular vehicle operation was found to particularly affect the early stages of spray evolution, and led to a marked increase in the cycle to cycle variability of the spray shape, with the variability in the cone angle being some 2 – 3 times greater for a fouled injector as compared to a clean one. Transient radial bulges were noted in the case of the fouled injector which could potentially reduce the axial momentum and hence detrimentally impact the combustion performance of the diesel engines.Droplets and ligaments formed at the end of injection from a multi-orifice injector were observed to be random and chaotic, varying from injection to injection and from orifice to orifice. Despite the adverse early fuel spray evolution from the deposit rich injector compared to the new injectors, the end of injection ligament and droplet formations showed no qualitative difference based on the condition of the injectors.

Roger Cracknell, R. Wardle, R. Pos, L. Ganippa

Concept for lower raw engine emission covering full engine map operation

Eaton and IAV are working on optimizing conventional Diesel combustion in close collaboration with a global OEM to further reduce engine raw out emission in real world driving. A combination of mechanical Supercharging, an exhaust Turbocharger, and highly dynamic EGR-Control enables new degrees of freedom for Diesel engine process control. The primary objective of this work is to reduce the load on the exhaust aftertreatment system.

Mike Lau, Ramita Suteekarn, Torsten Tietze, Marcel Pannwitz, Guido Lautrich



Simulation-based RNT measurements for oil supply optimization at the connecting rod bearing

In the present study a systematic approach for the evaluation of oil pressure reduction potential has been implemented. Therefore the connecting rod bearing as one of the most loaded parts of the base engine has been subject of the investigations. In a first step, the oil supply from the main gallery to the connecting rod bearing has been simulated using 3D-CFD. In successively decreasing the oil pressure a borderline oil pressure slightly above the cavitation limit was identified. In the next step these results were used as input data for EHD simulations. Here wear indicators were employed in order to verify the critical oil pressure identified by 3D-CFD. With these findings a modified engine was equipped with an activated connecting rod bearing shell and an appropriate RNT measurement system. Measurements were performed at production oil pressure, borderline pressures identified by simulations and a critical pressure below the aforementioned value. The parameters varied were engine speed and load, oil temperature, oil viscosity and oil aeration. The wear rates determined in these experiments justified a significant decrease in oil pressure without noticeable increases in wear rates. As a last step these findings were validated employing a production engine with a modified oil pump and a reduced pressure level. While a durability test confirmed the expected wear behaviour, the fuel consumption effort was identified in a WLTC test.The fuel consumption benefit in WLTC was identified to be 0.4% for 5W-30 and 0.6% for 5W-20, respectively. This outcome outlines the necessity to go through a thoroughly potential identification and validation process to realize even small efficiency gains.With the combined approach employed in this study the effort for cost-intensive RNT measurements could be reduced significantly. For future base engine development this yields an enormous cost reduction potential by substituting experiments by simulations.

Norman Fuhrmann, Arndt Döhler, Jörg Schäfer, Winfried Krebs, Dustin Schliemann, Achim Königstein

Dynamics and friction of a rolling bearing crankshaft – method and calculation

So far, the application of rolling bearings in combustion engines for light vehicles was restricted by higher costs, application effort, acoustics and the high maturity level of plain bearings. Driven by legislation and the customer request for higher efficiency, e.g. the application of combustion engines in hybrid systems, the advantages of rolling bearings against plain bearings come back into focus. Rolling bearings have advantages at numerous stop-start conditions because of their lower friction. The load out of the timing drive at the first main bearing at low speed is dominating the friction power loss of the crankshaft in the driving cycles. In addition, combustion engines nowadays are driven at low engine speed with high constant torque. At these conditions, high load at low speed, rolling bearings have the potential to minimize the friction loss and lower the wear risk.

Frank Schlerege, Christoph Brands, Carsten Weber, Urban Morawitz

Wear behavior of engine components affected by soot

Jens Jörns, Andreas Jäger, Wolfgang Optatzy, Bernhard Kehrwald



Passenger car diesel engine for 2020 / 25 – synthesis of classical attributes and novel high-tech innovations

The reduction of CO2 emissions remains one of the biggest challenges for every engine developer. Downsizing was an appropriated and proven way to reduce fuel consumption in the past, but nowadays it seems to be reaching its limits. In consequence of higher specific performance figures the peak firing pressure is rising and the crank train has to be adapted for the increased load by enlarging bearing dimensions and stiffening the crankshaft. These measures are increasing the engine friction and jeopardizing the benefit of downsizing.

Bernd Lindemann, Christoph Szasz, Joschka Schaub, Franz-Gerd Hermsen, Malte Berning

Thermodynamic consideration of the Miller cycle on the basis of simulation and measurements

With this paper an attempt was made to characterize the Miller cycle. Based on consideration of idealised processes, thermodynamic simulations and measurements it has been tried to reveal the fundamental aspects. Three different major features could be identified. Miller can be used for:– Dethrottling– Reduction of compression ratio– Outsourcing of compression with improved charge air coolingAll other perceptions and aspects of Miller cycle can be ascribed to one of the above items.Limits and benefits of Miller cycle thereby being a function of optimisation target. Possible targets are efficiency improvement, emission reduction, power increase and thermal management.When applying supercharging to a Miller type engine it can be stated, that the turbochargers efficiency becomes more important compared to conventional engines, and the mechanical supercharging may be more efficient than turbocharging.

Eberhard Schutting, Ortwin Dumböck, Thomas Kraxner, Helmut Eichlseder



Assessment of efficient powertrain concepts in real driving conditions

Driven by stringent CO2 constraints, engine friction and thus thermal operating strategies are key levers in the development of efficient powertrains. Conventional approaches for friction assessment are limited with respect to their validity for realdriving conditions. Thus, the potential in terms of fuel consumption and emission reduction cannot be fully exploited.In order to be able to assess the impact of friction reduction measures on fuel efficiency, the entire vehicle and representative driving cycles have to be taken into consideration. Based on physical models the interaction between temperature dependent component friction and vehicle warmup can be captured properly.This paper discusses the AVL friction toolbox which is based on physical and semiempirical models. The toolbox creates speed, temperature and load dependent FMEP maps which are input to a global engine and vehicle model. This model is founded on a VTMS (vehicle thermal management system) approach. Amongst others, it covers longitudinal dynamics, gear ratios as well as all thermally relevant systems like cooling and lubrication circuits.The capabilities of the aforementioned method are demonstrated on a passenger car gasoline engine. The study depicts the impact of measures like piston ring tangential force, switchable piston cooling in combination with variable oil pump, water pump and tailored operating strategies.

Heinz Petutschnig, C. Priestner, M. Tizianel, B. Thonhauser, D. Horvat, A. Ennemoser

Thermal management in vehicle integration

One central effect of Active Thermal Management is the significantly faster powertrain warm up. The warm up operation strategy is divided into two parts – the first step is Zero Flow, which is the fastest passive engine warm up method, and is followed by the warm up mode with speed controlled operation of the electrical water pump (eWAPU).Regarding Zero Flow the avoidance of coolant boiling represents an enabler for aggressive AND safe operation. The analysis of multiple temperatures led to the result that a temperature location “A” correlates directly with coolant boiling. Robustness had been ensured by performing experiments with plenty of Zero Flow tests in combination with an appropriate noise strategy. In parallel a physical temperature model had been developed to simulate the proper location.

T. Müller, M. Reichenbach, M. Selinger



Experimental studies on spark stability in an optical combustion vessel under flowing conditions

Besides mixture formation and combustion, ignition and robust flame kernel formation are the main parameters needed to realize the otto-cycle process. During much of the development history of combustion systems, the requirements on the ignition system have steadily increased but could always be fulfilled by the inductive ignition system. In contrast, some current developments in gasoline engine combustion concepts focus on the increase of cylinder charge which is often associated with supercharging or the increase of exhaust gas recirculation and/or air dilution. In such cases, the ignition and flame kernel formation becomes challenging. The increase of specific power by charging leads to higher gas densities at ignition requiring high ignition voltages of up to 40 kV which have to be covered by the ignition system. At part load conditions the ignition voltage demand is considerably lower, however the ignition conditions are much more critical due to low gas temperatures at ignition point and low chemical reactivity of lean mixtures. The electrical properties of the spark plasma, such as spark current, spark energy and spark duration as well as the interaction of the spark plasma with the internal engine flow are key factors in order to meet the aforementioned challenges.

Andreas Schneider, Philippe Leick, Alexander Hettinger, Hermann Rottengruber

3D CFD simulation of the spark ignition process under the consideration of spark channel deflection, diffusion effects, curvature and detailed chemical kinetics

The ignition process in turbocharged direct injection spark ignition engines is an important phase during the overall combustion process.Cyclic variations of e.g. charge motion and mixture formation have a strong impact on the spark ignition process and lead to irregularities in the consecutive combustion process and engine performance.These phenomena have been observed in extensive experimental studies at BMW and have motivated the development of a detailed spark ignition model for RANS CFD simulations since most of the existing commercial spark ignition models do not comprise detailed models to simulate the phenomena during the spark ignition process.In this work the advanced Curved Arc Diffusion Ignition Model (CADIM) for gasoline engines is presented which considers the influence of spark-channel deflection and curvature, diffusion and detailed chemical kinetics.In the advanced Curved Arc Diffusion Ignition Model the spark-channel is tracked by Lagrangian marker particles to account for the deflection of the spark-channel by the local flow field. The high local energy input during the ignition phase leads to steep gradients at the spark-channel, which cause temperature and species diffusion normal to the spark-channel. To account for these diffusion processes, the governing equations for temperature and species are solved normal to the spark-channel surface considering the influence of the spark-channel curvature.

Lukas Schäfer, Dirk Linse, Bodo Durst, Christian Hasse

Investigation of flame development applying optical metrology in a highly boosted SIDI performance engine for the sports car market

Optical measurements of the flame propagation inside an engine provide essential information for combustion process development. Many published studies in this field of research focus on low load and low speed engine operating points, as the utilized measurement techniques do not provide full load capability. Future emission legislations will include real driving emissions (RDE). As a consequence, there is a strong need for optimization of the full load range considering power and pollutant output.The present paper examines the combustion behavior of a highly boosted SIDI performance engine under high to full load conditions. The applied methodology is based on a fiber optical spark plug (FOSP) in conjunction with a high speed camera system. This approach provides spatial information about the flame position and its propagation and enables an assessment of the flame front velocity. The investigations focus on a variation of the air ratio lambda at constant engine speed and a variation of the engine speed with wide opened throttle.

Fabian Titus, Ulrich Spicher, Francesco Pulvirenti, Stefano Paltrinieri, Ruggero Cevolani, Jens Hadler



Optimization of the piston assembly friction

The present paper points out that improvements of the piston assembly friction necessitate a high level of system knowledge, which requires experimental investigations. Therefor the self-developed research engine of the Institute of Internal Combustion Engines of the Technical University of Munich is introduced. Besides the high accuracy of the measurement device a well-defined testing procedure is important to analyze the influence of specific design changes of the piston assembly on their frictional behavior. The presented testing methodology developed by the Institute guarantees the comparability of different testing configurations.Crank angle resolved measurements of two top ring design features were presented, which prove the positive influences regarding the piston assembly friction of a low friction coating and an optimized shape of the running face. The results illustrate in detail that these particular design changes only affects the friction force in the expansion stroke within high cylinder pressures. Although the impact on the friction force is pretty similar for both design changes the given reasons for the effects differs. Furthermore, the results show that with higher engine load and lower speed the improvement of the frictional losses increases. Thus, both design changes are an effective way to optimize the mechanical efficiency of an internal combustion engine.

Stefan Graf, Fabian Ruch, Richard Mittler, Georg Wachtmeister

A novel approach for valve train reduction

Duraiarasan Saravanan, R. Govindarajan



Advanced model-based diagnosis of internal combustion engines

Model-based methods allow to detect and diagnose faults earlier and more detailed compared to classical limit checking and plausibility checks of directly measurable signals. The effect of faults by using signal models is, e.g. shown in changes of their frequencies or amplitudes. Process models allow using changes of the input-output behavior expressed by their parameters, state variables, or parity equations. This was illustrated for categories or groups of a diesel engine in form of the intake system, the injection system, and the turbocharger. Some results were also summarized for a direct injection gasoline engine. Corresponding methods can be developed for the combustion and mechanics and for the exhaust gas aftertreatment. Integrating the faultdetection results of all categories allows a comprehensive fault-diagnosis coverage of diesel engines and similarly for gasoline engines in addition to the known OBD functions.

Rolf Isermann

Control of predefined diesel combustion processes by a burn-rate model

The interaction between air-path and injection system is of great importance for the future engine control concepts. Currently, some of these interactions like reduction of the injection quantity at the smoke limit are considered. However, a physically-based consideration of the real effects of the intake air states like temperature, pressure, and composition under transient engine operating conditions should be more developed.In this study, first a phenomenological combustion model for calculation of the burnrate from the given injection pattern is presented. This forward model is a platform for optimization of the burn-rate for different operating conditions and is used in the next step for model inversion. The main idea here is to explicitly invert the sub-models and physical modules of the forward model in order to inversely calculate the required injection rate for realization of the pre-defined burn-rate.The information about the air-path system, intake air conditions as well the preoptimized burn-rate are directly given to the phenomenological inverted combustion model and this inversely calculates the required injection pattern to realize and control the target combustion process. The developed model is coupled to an engine model and validated against the experimental results.

Reza Rezaei, Enrico Neumann, Maximilian Brauer, Christopher Severin



The future of RDE

Christof Gietzelt

Current and future challenges in the field of powertrains

Jens Hadler



Energy supply for vehicles – can it be regenerative?

Lars Mönch, Martin Lange

Review of combustion engine efficiency improvements and the role of e-fuels

Over next decade, SI engines might adopt a significant amount of design solutions from CI engines. Therefore none of both can be finally called the winner – they are merging into an optimized engine for future sustainability requirements and heavily depend on technology readiness and technology cost, customer acceptance as well as total cost of ownership assessments. The fuel of choice (e.g. E-methane and E-DME) might determine which engine type can deliver lowest CO2 emissions.To enable deep CO2 emission reduction by e-fuel deployment in the long run, CO2 should be extracted from the atmosphere to enable a closed-loop carbon cycle. In the mid-term and due to cost-benefits for CO2 provision, the utilization of CO2 from unavoidable sources based like steel works might be an option.All presented options to further reduce CO2 emissions require additional efforts towards the implementation into the vehicle fleet and fuel supply infrastructure.

Heiko Maas, Andreas Schamel, Carsten Weber, Ulrich Kramer



Alternative fuels in the well-to-wheel debate

Patrick R. Schmidt, Kurt Kirsten, Jens Hadler

Synthetic fuels from biomass: Potentials and viability

In view of a world-wide growing fuel demand coming along with a strong environmental impact, exploration of alternative resources, preferably renewable ones, is vastly stimulated. Regarding carbon-based fuels, biomass is the only renewable feedstock which can be converted efficiently to fuels employing either fermentative or chemical processes. Naturally, the use of residues and wastes is preferred to circumvent competition with customary markets, especially the nutrition sector. Typical fermentative procedures, which are already employed on large scale, are the production of ethanol from sugars, starch or cellulose as well as methane production via anaerobic digestion of biomass.

Jörg Sauer, Ulrich Arnold, Nicolaus Dahmen

The sun in the tank? Possibilities and limitations of MtG technology from the chemical perspective

Martin Bertau, Ludolf Plass, Konstantin Räuchle, Michael Kraft



Electric mobility with hydrogen – quiet, efficient and with zero emissions

Birgit Scheppat

Production of methanol and oxymethylene on an industrial scale

Torsten Buddenberg, Christian Bergins, Wolfgang Maus, K. C. Tran

Novel methods of synthesis for diesel fuel OME

Eberhard Jacob, Wolfgang Maus



Contribution of fuels towards reducing CO2 emissions in traffic

Thomas Garbe, Jörn Kahrstedt, Martin Hönig, Tina Erler

The new Mercedes-Benz EU VI medium-duty CNG engine in bus operation

The necessary introduction of Euro VI leads to the decision of Daimler to develop a common natural gas engine platform for Mercedes-Benz trucks and buses. The new 7.7 l engine M 936 G replaces a 6.9 l and a 11.9 l engine. The main target is to have many commonalities with the Diesel engine of the same platform. From the bus application view, the downsized gas engine enables a common engine compartment, reduced weight and fuel consumption, longer service intervals and lower noise. EvoBus and Daimler development groups were solving challenges like local high engine periphery temperatures and acceleration performance. With adapting the new gas engine to the Citaro C2 generation better load distribution, new vehicle electronics and a new gas tank system with easier access is introduced.

Gerhard Urmann



Oxymethylene ether (OME1) as a synthetic low-emission fuel for DI diesel engines

In long term the greenhouse gas (GHG) emissions have to be reduced stringently. One way to achieve this goal is the substitution of fossil fuels through CO2-neutral fuels. There are gaseous and liquid fuels possible to use. Liquid fuels have advantages in terms of logistics, energy densitiy and conventional storage technology. Fuels from biomass are critically evaluated because the savings in greenhouse gas emissions remain marginal considering the changes in land use and bring significant degradation of fuel quality with it. [1,2] An EU study including the indirect land use changes (ILUC) shows that Biodiesel leads to a CO2 increase of 9 to 20 %, compared to using mineral oil-based diesel fuel. [2]

Markus Münz, Alexander Feiling, Christian Beidl, Martin Härtl, Dominik Pélerin, Georg Wachtmeister

Powertrain mixture 2030 – influencing factors and outlook

Thomas Schlick, Wolfgang Bernhart, Markus Baum



Future HD vehicle requirements due to legislation and effects on CO2 and air quality

The actual EURO VI regulation based on WHTC, WHSC and on on-board emission tests led to very low emission levels of HDV also in real driving conditions. Consequently the focus of the development will shift more and more towards low CO2 emissions and better fuel efficiency.As important basis for further steps and for neutral information of customers on the fuel efficiency of different trucks, a certification method for CO2 and fuel consumption of trucks is being developed. The method is based on component testing and vehicle simulation using the component test data as model input.Due to the NOx – fuel efficiency trade off a proper monitoring of NOx emissions in the engine test procedure seems to be important to maintain the excellent NOx emission behaviour of HDV in real world driving.The NOx monitoring certainly shall not add unnecessary burden to the engine manufacturers. The best compromise between effort and robustness is still under discussion. The ISC emission test procedure with PEMS equipment covers most of the relevant load points in the actual version. If the threshold for the average engine power of the MAWs in the test is reduced to 10% of the rated engine power, all relevant load points would be covered. Nevertheless relevant shortcomings of monitoring the steady state fuel map by NOx measurement in ISC exist. NOx measurements in real driving conditions would not detect if fuel efficiency optimisations at the expense of increasing NOx are applied to the engine only at the steady state conditions which occur during the engine fuel map measurements and in general (illegal) test engine specific optimisations can also not be monitored by ISC since different physical engines are used.

Stefan Hausberger, Martin Rexeis, Antonius Kies, Konstantin Weller, Gérard Silberholz

Experimental studies of dual-fuel combustion modes for heavy-duty application

At the moment Diesel powered engines are still and by far the most commonly used setups for heavy duty applications. Compared to this 5 alternative approaches have been shown. Every combustion mode has its own advantages and disadvantages. Some of those shall be pointed out in comparison to Diesel, but are also compared among each other.All applications which use a gaseous fuel have the disadvantage of the lower energy content in relation to the tank volume. This especially applies to Hydrogen. But the shown Hydrogen/Diesel Dual Fuel approach might be an alternative e.g. for urban use (busses, garbage collection …). The low emissions in the raw exhaust gas allow the use of a rather simple nitrogen oxide exhaust gas aftertreatment system for EURO VI.

Klaus Dieter Barnstedt, Peter Grabner, Helmut Eichlseder



Progress in the development of natural gas high pressure direct injection for Euro VI heavy-duty trucks

Injecting natural gas directly in the combustion chamber at the end of the compression stroke, High Pressure Direct Injection (HPDI) of Natural Gas, ignited with pilot diesel fuel, preserves the fundamental characteristics of diesel combustion such as high efficiency and high specific torque. High combustion efficiency coupled with the lower carbon content of natural gas results in the potential for significant reductions in greenhouse gases. Furthermore because the technology is fundamentally a diesel-like combustion, the powertrain requires few modifications, enabling the manufacturers to preserve and benefit from their diesel investments.

Patric Ouelette, Dale Goudie, Gordon McTaggart-Cowan

Reduction of in-cylinder emissions on a dual-fuel engine

Fuel costs and increasingly stringent emissions standards are driving the need for more efficient internal combustion engines. Diesel or Compression Ignition (CI) engines remain an efficient option due to their high compression ratio, high combustion efficiency, and un-throttled, lean operation (1). The inherent high torque capability and thermal efficiency are the reason diesel engines remain a particularly attractive option for the Heavy-Duty (HD) transportation sector. Long duration, medium to high load operation prohibits the usage of passenger car technology, such as hybridization or electrification, for increasing vehicle fuel efficiency.

Steve Whelan, Hoi Ching Wong, Ian May, Alasdair Cairns

Safeguarding the reliability of natural gas engines for commercial vehicles

In summary, the following conclusions can be drawn:• Many arguments support the use of natural gas engines in the commercial vehicle sector. The potential for a reduction of the greenhouse gas emissions, ultra-low exhaust emissions, a favorable NVH behavior and fuel prices.• The introduction of newest US and EURO VI legislation causes a trend to stoichiometric combustion systems with three-way catalysts. A combination with external cooled EGR is a suitable means for improving the efficiency and reducing the exhaust gas temperatures.• The natural gas variants are in general derived from diesel engines. To safeguard the reliability of the gas variant, a part of the development work of the diesel engine can be transferred. However, due to the changed combustion system with new or modified components, additional tasks have to be handled during the development process.• Safeguarding the reliability is done on the one hand by engine control. Besides the control of AFR which is essential for the exhaust gas aftertreatment, most important items are EGR and knock control. On the other hand, the development of engine mechanics has to respect the changed boundary conditions, especially the higher combustion and exhaust gas temperatures and the changed hardware.

Thomas Rinkens, Christoph Biwer, José Geiger



Controllable cooling system for heavy-duty commercial vehicles

It was shown that an energetic optimization of the truck cooling system can be achieved by including a map controlled thermostat, a Visco® fan, a Visco® coolant pump and by applying a smart control strategy. The underlying principles are to minimize the coolant volume flow, reduce fan engagement and to increase the coolant temperature under part load conditions. With a predictive cooling approach additional benefits concerning the reduction of fan engagement, extended retarder operation and drivability can be realized. A very promising next stage of expansion is changing from direct charge air cooling to an indirect system. Investigations at MAHLE have demonstrated that indirect charge air cooling shows, beside improved transient engine performance, a potential consumption reduction[4].

Eberhard Pantow, David Haar, Andreas Kleber, Matthias Banzhaf

Safety concept for a HD on-road waste heat recovery

Alongside various other technologies, exhaust gas waste heat recovery by means of a Rankine cycle with an organic working fluid will play a significant role in tackling real on-road CO2 targets for long haul truck applications. A comprehensive investigation has been made on an IVECO Stralis truck ensuring safe use of the vehicle by adapting the system architecture and the control strategy. Finally, the system has been successfully and safely tested in the vehicle under real world operating conditions.

Fabio Cococcetta, Michael Glensvig, Peter Krähenbühl, Ivan Calaon

Electrically assisted turbocharging in long-haul truck application

Electric charging systems were investigated with regard to its performance potential on a classical 12L class heavy duty diesel engine. To assess the overall system behavior and to find best system configuration, characteristic operation modes for electric boosting and electric energy recuperation were investigated by 1/D simulations. Besides this detailed analysis in selected load points, a more holistic analysis was executed by a combined engine, vehicle and drivetrain simulation considering mixed highway, country road and city drive situation of a 40 ton semi-trailer truck. As a boundary for the electric boosting and electric energy recuperation systems a 48 V vehicle on-board power network was considered.

Hans Felix Seitz, B. Blankenbach, P. Gratzl, H. Schreier, H. Theissl, G. Wagner



Potential of the SCRF® concept for future legislation

• The engine test results confirm the high potential of the SCRF® technology in NOx and total EAS volume reduction• The high NOx conversion of the SCRF® in the WHTC indicates the potential to go with the SCRF® only (w/o SCR) for current EURO VI limits• NH3 uniformity > 0.98 was achieved in all tested operation points

Gudmund Smedler, O. Sonntag, P. Marsh, M. Decker

New combustion system meeting Tier 3 emission standards for emerging markets

Engine development of the last 20 years had to put a focus on emission compliance with step by step tightened standards in EU and USA. Emerging countries very often had no emission regulation or less demanding standards which were comparable with earlier standards of the western hemisphere. Therefore the export into these countries was served with engines using the well proven and robust technologies.For Non-Road Mobile Machinery (NRMM) many countries like the BRIC states are demanding for emission standards similar to the US Tier 3 and EU Stage III A legislation. Also therefore existing technologies could be exported.Deutz now has found a new improved combustion approach without EGR which allows serving these markets. Based on 3D calculations on combustion followed by intensive testing and calibration work, it was possible to define a combustion system, which allows making a big step forward taking into account emission compliance, system costs, fuel consumption and engine dynamics.Within this presentation Deutz wants to show a cost efficient technology approach and the way forward of its market introduction.

Heiner Bülte, Hartmut Sieverding, Markus Schwaderlapp



Validation of a 4-cylinder engine concept for heavy-duty vehicles with a parameterized model

Carrying over the major trend of downsizing from passenger cars to commercial engines is not entirely possible for several reasons. One reason is that commercial engines have to also comply with the most stringent exhaust gas emission limits at full load. Another one is a much higher requirement regarding the life time of the engine. Both reasons limit the achievable specific performance to a rather low level compared to passenger car engines. Nevertheless development engineers are challenged more than ever with the need to reduce fuel consumption, size and weight of heavy duty engines. Moreover this has to be fulfilled at acceptable engine costs. This paper shows a possibility to combine the advantages of downsizing with the requirements of a commercial engine. This is achieved by reducing the number of cylinders but keeping the total displacement of the original engine.The focus of the research is a 215 kW truck engine with a displacement of 7.4 l. This engine is realized as a 6 cylinder and as a geometrically similar 4 cylinder engine. Both engines are designed in CAD for geometrical investigations and in new engine models for thermodynamic investigations. The thermodynamic models were parameterized in terms of heavy duty engines. This models answers questions of friction, gas exchange and fuel consumption. Furthermore the models can be used for a wide range (3 l – 15 l displacement) of commercial vehicles.The aim of this article is to provide a short overview of the structure of these different calculation models. These tools are developed for the very early stage of an engine design to judge about the engine performance beyond the application scope of the final engine. In summary each tool was used to compare the new engine layout of the 4 cylinder in contrast to a 6 cylinder engine in special and commercial engines in general.

Peter Methfessel, Katharina Eichler, Thomas Ebert, Michael Neitz

Challenges in the development of high performance engines for the off-highway sector

To fulfil actual customer demands, R&D departments have to solve a trade-off between increasing power and torque demands in agriculture engine applications and to install the whole engine in the existing small engine package environment. Based on the increasing size of agricultural holdings, combined with the demand to reduce operating costs as much as possible, this has led to a requirement for tractors with high power and high torque, but which remain compact, highly versatile and highly manoeuvrable. To achieve good tractor manoeuvrability, a very compact package is required. In particular the width of the engine which is limited by the steering lock. The main focus subsequently is on operating costs. Both require a high power density. In addition to these demands, there is a high service life expectation of at least 10,000 hours. As well as a need for high power density, the tractor must be capable of operating continuously under a wide range of conditions. In order to meet these demands, dual-stage turbo charging technology with intermediate charge air cooling has been chosen. The following article will describe the segment-specific demands and the engine technology, including the special challenges for the agricultural application. Later on the validation process for such a special application product will be described.

Markus Schwaderlapp, Manfred Pister, Jürgen Darscheidt, Thomas Hoen



Robustness-related development of MAN’s D38 heavy-duty engine

Thomas Leitel, Ulrich Wiebicke, Ulrich Boehme, Florian Kraft

Powertrain technology for commercial vehicles – a look beyond 2020

In the upcoming years the overall efficiency increase of powertrain architecture will play a dominant role in the commercial vehicle segment.This segment will face the stepwise optimization of the current diesel powertrain.Engine optimizations, such as downspeeding or improved turbocharger efficiency, will be accompanied by improved exhaust gas treatment systems. In addition the reduction of friction losses and the optimization of auxiliary components will contribute to reach the current discussed EPA GHG phase II proposal for 2027.

Thomas Lengenfelder, Rudolf Maier, Michael Krüger, Christian Barba, Secil Konus, Alexander Schulte
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