Internationaler Motorenkongress 2017

Inhaltsverzeichnis

1. Frontmatter

2. PLENUM

   1. Frontmatter

   2. Propulsion for 2025

      Michael Winkler

      Abstract

      Overall industry and thus also automobile industry is currently changing dramatically driven by digitalization. Future mobility will be more than moving from A to B. The car of the future will be the connection between digital world and passenger. In the far future it is likely that it will be electric, connected and autonomous.

      Four key megatrends – demographic change, urbanization, environmental policy and connectivity – are analyzed in relation to their impact on people, future mobility and therefore on the automobile industry.

      Market forecasts predict an increase in the share of electrified vehicles from today 3 % to 27 % in 2023. However the share of pure electric vehicles will remain on a comparatively low level below 5 %. In order to meet upcoming CO₂ legislation a strategy of improving the conventional gasoline and Diesel engine as well as introducing a wide range of eco-friendly vehicles is required. With the fuel cell ix35 Hyundai is offering today the technology of tomorrow.

      Automated driving – thus car is capable of sensing its environment and handling of navigating tasks under all roadway conditions without human input – will become reality step by step.

      This presentation describes the Hyundai Motors development roadmap to satisfy the requirements towards future mobility in terms of innovative powertrain technologies, connectivity and autonomous driving.

   3. Worldwide harmonization of emission regulations – a dream never becomes reality?

      Manfred Schuckert

   4. Climate-neutral mobility

      Lars Mönch

      Abstract

      Quote from: ‘Natural Gas and Renewable Methane for Powertrains’ Future Strategies for a Climate-Neutral Mobility

      “An element in the action plan to achieve the global 2-degree goal is that transportation at least massively limits the growth in its greenhouse gas emissions or rather contributes significantly to a reduction in emissions. This is necessary on both a national and a global level. The whole world is experiencing a massive surge in the growth of the volume of traffic: all forecasts point to further growth. It is therefore a problem of global proportions for which an exclusively national view is insufficient. Apart from the different boundary conditions in the various regions, it must be noted that the different transportation platforms have different growth and have different potential and options for the reduction of greenhouse gases. Forecasts assume that the GHG emissions due to transportation will more than double by 2050, from 6 GtCO_2,eq to 14 GtCO_2,eq.

      Since economic growth and traffic growth are coupled in many countries, steps to drastically reduce the volume of traffic or to reduce its growth are politically difficult to impose. The conclusion is that it is highly probable that only minor successes can be achieved in this area. It appears that the key to the traffic-based climate issue lies in the domain of traffic energy supply.

      There are a variety of options available for the different transportation platforms: The direct use of electricity based on renewable energy is practicable. The current level of knowledge states that there are no short or medium term globally available options for the direct use of electricity for heavy-duty traffic, shipping or aviation. However it must be mentioned that the direct use of electricity in commercial vehicles is in its infancy. Since the greenhouse gas emissions from the traffic sector from a global perspective are currently still increasing, the pressure to act and solve issues in traffic is growing rapidly. It is therefore high time to develop strategies to make technologies and energy carriers available for the transportation sector and if possible other sectors too that have no negative impact on the climate.

      An important element in such a strategy is, according the wisdom of today, the production of synthetic methane utilizing electricity. This affects the purely technological availability of production and its future development. It can be the basis for a climateneutral energy supply for transportation, where for example direct use of electricity (rail, passenger car, light‑duty trucks) is not possible. Without a massive increase in the development of renewable electricity supply up to the time corridor 2050-2070, this technology, as a contribution towards climate protection, is however not very practicable. In parallel to this important initiative, the basis of every action in the transport sector is to significantly reduce the specific energy consumption of each individual traffic platform to dampen the growth of transportation effort.

      The use of synthetic methane is practicable in view of the already widely available infrastructure.

      Natural gas has the potential of reducing the CO2 emissions in traffic due to its physical properties (C / H ratio): It increases the efficiency of Otto engines since higher compression ratios are possible; methane can also be produced synthetically. Natural gas represents a step towards greenhouse gas neutral transportation. The next step would be the fastest possible formulation of a globally effective strategy for the industrial production and use of electricity-based fuels from renewable energy sources (for example PtG-methane) and the direct use of electrical energy in the transportation sector. At the same time, directed further development of the technical processes needs to be initiated, unless other more realistic methods can be found how to achieve the 2-degree goal without having to use electricity-based fuels.”

3. TEIL I: PKW-MOTORENTECHNOLOGIE – MOTORENKONZEPTE

   1. Frontmatter

   2. CNG as ideal supplement to e-traction aiming at CO2-neutral mobility?

      Wolfgang Demmelbauer-Ebner, Jens Andersen, Reiner Mangold

      Abstract

      When it comes to reducing the emission of CO₂ and pollutants in the mobility sector, electrified drivelines are currently a particular focus of public interest. Interest in the use of CNG as a way of reducing the CO₂ emissions of road traffic, however, is considerably less widespread. The commitment of most vehicle makers and their system developers is similarly low in respect of CNG.

      This paper shows that CNG vehicles are already making a significant contribution to the reduction of CO₂ emissions. Furthermore, a cross-sector analysis of the future energy market demonstrates that CNG is extremely well suited as a partner to the electricity market within the context of the energy transition. CNG vehicles are therefore the ideal addition to e-traction on the road to CO₂-neutral mobility.

   3. Challenges facing future high performance combustion engines using Porsche Boxer engines as an example

      Thomas Wasserbäch, Jörg Kerner, Markus Baumann

      Abstract

      The future of the combustion engine is currently under discussion. The future viability of high-performance engines for Sports Cars in particular is the subject of debate. Legislative requirements worldwide are subject to dynamic change, and there is also a significant shift in customer demands. Both of these factors must be brought into line with the Porsche brand philosophy – after all, Porsche Sports Cars have always been synonymous with tradition and innovation.

      The challenge for the future will be to meet these requirements with innovative technical solutions. Taking Boxer engines as an example, where does further potential exist and where do the conceptual advantages and disadvantages lie? In this paper we address the issues of combustion processes, exhaust gas aftertreatment, mechanics, fuels and electrification for Boxer engines by reference to examples.

   4. Load point shifting for Diesel engines – potentials for passenger car and truck engine applications

      Jörg Neugärtner, Alexander Scholz, Anton Schurr, Michael Günthner, Rudolf Flierl

      Abstract

      Public discussion concerning the “Dieselgate” scandal creates the impression that the Diesel engine is at the end of its life and does not need further development efforts. In reality, the Diesel engine in passenger car and truck application is and will be realizing the major duties for transportation of passengers and goods.

      Current engines were developed regarding the former market requirements, i.e. with respect to the legislation boundaries of the last decade. In fact, in the last decades, a reduction in particle emission of about 99 % and about 20 % for CO₂ emissions has been realized (please also refer to Mollenhauer and Tschöke).

      Upcoming fuel consumption requirements and future legislation levels will force further improvement of consumption and emissions of Diesel engines. This implies test cycles like WLTP (Worldwide Light Duty Vehicle Test Procedure) for passenger car or WHTC (World Harmonized Transient Cycle) for truck applications, and furthermore also real world driving cycles in the future. In particular, Real World Driving Emission (RDE) monitoring requires a special focus for almost all vehicles equipped with Diesel engines in future. Furthermore, the discrepancy between test cycle and “real world” consumption in passenger car applications is a concern of vehicle users and authorities worldwide. For the application in trucks and other commercial vehicles (e.g. off-highway and agricultural machines), consumption under real world payload conditions is a major factor for business success of cargo companies and other commercial vehicle users. As a result, fuel consumption in most Diesel engine applications needs to be improved further, leading to drastically increased development efforts compared to the past decade of development.

4. TEIL I: PKW-MOTORENTECHNOLOGIE – LADUNGSWECHSEL UND VERBRENNUNG I

   1. Frontmatter

   2. Selecting a suitable stroke / bore ratio when combining variable compression and Early Intake Valve Closure (EIVC)

      Marc Sens, Michael Günther, Ulrich Walther, Sascha Nicklitzsch, Jan Müller, Matthias Hunger, Steffen Zwahr

      Abstract

      Increasingly strict fuel consumption and emission legislation is forcing engine developers to use combinations of technologies that complement each other to produce high potential for cutting fuel combustion.

      For this reason, IAV has examined future-oriented technologies initially for their individual potential and then with a special focus on their complementary potential. The combination of geometrically variable compression (VCR) and early intake valve closure (EIVC) proved to be especially promising in early studies. It transpired that both technologies enhance the inner efficiency. It is worth noting that while early intake valve closure reduces pumping losses, it is detrimental to combustion quality and residual gas tolerance due to a loss of temperature and turbulence. This comes from the smaller tumble energy with the reduced valve lift and from cooling the cylinder charge under intermediate expansion to BDC.

   3. Extreme lean gasoline technology – best efficiency and lowest emission powertrains

      Philipp Adomeit, Johannes Scharf, Matthias Thewes, Bastian Morcinkowski, Patrick Hoppe, Stefania Esposito, Marius Böhmer

      Abstract

      Development of mobile propulsion technology is driven by fuel consumption and exhaust emission reduction. New gasoline powertrains currently developed at FEV address both these major trends using extreme lean combustion systems to combine best efficiency with lowest emission levels. This paper elaborates on the technology potentials and development methodologies used to handle challenges associated with gasoline lean burn.

      One focus lies on the definition of a central DI combustion system, which is capable for stable operation at rel. AFR of >1.9 and an outstanding thermal efficiency by charge motion and combustion chamber optimization based on FEV’s CMD approach. A further focus is put on the analysis of suitable boosting systems and stoichiometric- lean switching strategies, which is obtained here by a combined TC and e-charger system in combination with a two-step variable valve lift system. The performance of such system investigated in detail by gas exchange simulation including a comprehensive lean combustion model capable to predict cyclic combustion stability. Finally, the CO₂ and fuel consumption reduction of an extreme lean GDI engine concept is compared to an equivalent stoichiometric engine.

   4. From glow tube to corona – challenges to the ignition systems of future SI engines

      Joachim Hahn, Martin Schenk, Franz Xaver Schauer, Christina Sauer, Gerhard Weber, Christian Schwarz

      Abstract

      Whether being „the problem of the problems“, as Carl Benz called it, or the central, even eponymous component: The challenges as well as the chances of the ignition system have accompanied the past 150 years of SI engine development.

      Within this process the activities focused for a long time on the development of lowcost, robust and as maintenance-free as possible ignition components to assure, in context with the developments of the injection systems, a reliable engine operation under all climatic conditions. With rising awareness towards exhaust emissions and for this reason increasing legislative requirements, the functional demands on the ignition process increased considerably since the 1970’s. The legislative restrictions with respect to the emissions of pollutants – gaseous as well as particulate emissions- are continuously rising ever since. This is accompanied by the necessity of a continuously rising engine efficiency to meet the steadily more severe CO₂ fleet emission limits.

      The adaptations of the SI-engine combustion strategies as a consequence of these requirements, such as charge dilution or gas exchange strategies, often significantly impede the inflammability of the mixture. Thus, besides the measures for the generation of a higher level of charge motion, it is especially the optimization regarding the ignition systems, which allows an extension beyond the currently valid tolerance limits. Hereby, besides the stationary demands of the engine map, especially the necessities of the transient engine operation as well as the worldwide performance compliance have to be taken into account.

      Within our presentation the potentials as well as the limitations of various ignition innovations are discussed. We will look upon optimizations of the classical spark ignition, referring always to today´s serial solution, as well as upon alternative, spacious ignition systems. Besides the evaluation of the stationary potentials, especially the transient and realization relevant aspects will be illustrated. The resulting demands and potentials towards an automotive industrialization will be discussed.

5. TEIL I: PKW-MOTORENTECHNOLOGIE – SYSTEME UND METHODEN

   1. Frontmatter

   2. Experimental investigation of the cold start behavior of different coolant circuits for a waste heat recovery system and their influence on the engine

      Thomas Matousek, Frank Stahl, Thomas Koch, Michael Bens

      Abstract

      One of the most promising technologies to increase efficiency and to decrease CO₂-emissions for future combustion engines is the utilization of exhaust gas heat through a Rankine cycle. A so called waste heat recovery system (WHR) converts the thermal energy of the exhaust gas into mechanical or electrical energy which can be used to propel the vehicle or to lower the generator load and thereby reduce the fuel consumption.

      Additional to the recovered electric or mechanic energy the engine can also benefit from the recovered heat, which can be regained through the condenser. The condenser can be connected to the coolant circuit where the heat can be used to improve the warm up of the engine and passenger cabin of the vehicle. This creates further potential to increase the efficiency of the whole system during warm up.

      The target of this study was to display the warm up behavior of WHR system and engine during cold start at different starting temperatures (0° to +20°C) under realistic conditions for different coolant circuit configurations. Preliminary investigations were performed to identify the appropriate coolant volume flow rates and circuit configurations to improve the warm up of the desired component. The resulting temperatures of the components and the fuel consumption of the whole system were the main focus points.

      The tests were conducted on a 4-cylinder 2.0 l SI engine which fulfils the EURO6 standard. A WHR system consisting of components as close-to-production as possible was applied. Engine and WHR system were put on a test bench which allowed lowering its chamber temperature down to 0°C.

      The results show that a Rankine WHR system is able to improve warm up of the engine and its components. The fuel consumption can be decreased due to the reduced warm up time while the cabin temperature can be increased. Power output seems not to be affected by the lower environment temperatures, which means a WHR system is able to provide even more benefits in efficiency for cold start scenarios.

   3. Method for the predictive calculation of mixed friction

      Morten Kronstedt, Christian Lensch-Franzen, T. Doğuer, M. Bäse

      Abstract

      From the perspective of legislative requirements on combustion engines in regards to exhaust emissions, CO₂-efficiency as well as higher specific loads from downsizing measures, friction reduction is especially important. Wear can over time affect the performance of components which for instance is likely to have a negative effect on the emission robustness of an engine. Under the new legislation for emission requirements the engine must meet the requirements over the lifetime of the engine. Deterioration in emission performance due to wear of components will have to be considered when setting the engineering target for the emission performance of the engine.

      In this context the APL Group is developing an energy based friction and wear model for predictive calculation of friction and wear in lubricated contacts. It allows for more focus on friction and wear related issues earlier on in the development cycle.

   4. Predictive diagnostics solutions beyond big data

      Michael Hackner, Walter Lehle

      Abstract

      Predictive diagnostics introduces new service models to enhance the availability, to optimize maintenance intervals and to reduce maintenance time and costs of vehicles and machines.

      The article gives an overview about concepts and methods of predictive diagnostics.

      Predictive diagnostics has to be use system and component knowledge, combined with existing and new algorithm and vehicle and environmental data. Target of this service is the prediction of upcoming component breakdowns during daily operation using state based pro-files and optimization of the period inspection. With this information the vehicle driver, automobile manufacturer or fleet management shall be enabled to plan a maintenance window or an exchange of the affected component in advance. Thus an unplanned breakdown can be converted into a predictable maintenance event.

6. TEIL I: PKW-MOTORENTECHNOLOGIE – EMISSIONEN

   1. Frontmatter

   2. Optimized heat release rate for enhanced thermal efficiency under NOx, noise and peak firing pressure constraints in light-duty Diesel engines

      Jean-Marc Zaccardi, Frédéric Nicolas, Jordan Rudloff, Gaetano De Paola

      Abstract

      Engine manufacturers have to face stringent emission regulations worldwide while maintaining performance and drivability targets as high as possible. However, some strong paradigm shifts are still necessary to further improve the typical trade-off between fuel consumption and tailpipe emissions of Diesel engines.

      Split-of-losses analyses have shown that improvements in fuel efficiency could be obtained by optimizing the combustion timing and duration. More generally, this article aims at showing that a fully optimized heat release rate could help in increasing the efficiency while complying with NOx, noise and peak firing pressure constraints.

      The reference engine for this study is a 2.3L Euro-6 compliant engine used for light commercial vehicles and passenger cars. First, experimental heat release rates have been modeled for different operating points by spline functions using a reduced number of relevant parameters. Then, based on these parameters, numerous heat release rates have been defined thanks to a design of experiments approach. Engine performance such as fuel consumption, noise, NOx emissions and peak firing pressure have then been quantified on a 0D single cylinder engine simulation platform. To do so, a new two-zones combustion model has been developed, allowing the user to specify the heat release rate due to combustion while quantifying the NOx emissions.

      All these steps define a complete workflow which allows the optimization of the heat release rate in different operating conditions. Thanks to this approach, it has been shown that the fuel consumption could be reduced by 5.5% at 3000 rpm full load and by 2% at 2000 rpm middle load. Finally, these works do not only confirm that the NOx emissions and noise can be lowered by controlling the very beginning of combustion, but they also show that the fuel consumption strongly depends on the duration of the second half of combustion.

   3. Impact analysis of fuels, operating fluids and combustion parameters: focus raw emission behavior

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

      Abstract

      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 simulation tools and dynamic measurement equipment, as well as a detailed understanding of the physical phenomena and mechanisms are essential.

      For evaluation of a powertrain under worst case boundary conditions RDE cycles and synthetic cycles are generated on the basis of real driving data from stationary and dynamic analysis and implemented on the test stand by support of a simulation model for vehicle, cycle profile and different boundary conditions. As an example combustion process and calibration strategy in regards to mixture formation, fuel/wall film interaction were investigated due to RDE sensitivity. The calibration over the complete operating map relevant for RDE requires a systematic methodology with Design of Experiments (DoE). A significant influence as well as optimization potential was identified by investigating the influence of hydraulic and chemical characteristics of both, fuel and oil on the restriction of calibration parameters with regard to the target figures combustion efficiency, emissions and combustion stability. Depending on the specific formulation and even interaction of fuel and oil there is a significant restriction in combustion parameters, compromising combustion efficiency.

      The results show the influence on the particle formation based on an example with mixture formation parameters. Coming from the higher dynamic shares within real driving, new areas for optimization unfold, especially during transient engine. In order to comply with the future legislative boundary conditions, the quality and speed of the air and fuel path control must be realized with lowest possible spray-wall interaction.

      The APL Group has developed a complex chain of methods and tools with the focus on RDE capability. The basis is the repeatable implementation of representative real driving conditions on powertrain and engine test beds. The so gathered data is used for further analysis in regards to operation parameters and especially the interaction between fuel and oil formulation for holistic combustion process optimization.

7. TEIL I: PKW-MOTORENTECHNOLOGIE – ELEKTRIFIZIERUNGSKONZEPTE

   1. Frontmatter

   2. FEV ECObrid – a 48V mild hybrid concept for passenger car Diesel engines

      Joschka Schaub, Christian Frenken, Bastian Holderbaum, Philip Griefnow, Rene Savelsberg, Olivier Coppin

      Abstract

      Powertrain electrification is a key to compliance with future exhaust emission and CO₂ limits. Besides conventional 12 V systems and high-voltage hybrid architectures, 48 V mild hybridization offers significant fuel economy potential and advanced emission control without the need for an entire powertrain redesign. The 48 V power net enables high recuperation capability, improved stop-start functionalities as well as electrical boosting by an electric compressor (e-Compressor) or belt-driven starter generator (BSG).

      The paper summarizes the key findings of a joint project between FEV and Valeo investigating the potential of mild hybridization and electrical boosting for a downsized passenger car Diesel engine. The considered engine is the well-known FEV HECS concept in its third generation, consisting of a 1.6-liter 4-cylinder engine with single stage VNT turbocharger, e-Compressor, 48 V BSG and dual loop EGR. The engine has been installed in a D-segment vehicle with a dual-voltage electrical system and an advanced model-based engine control unit (ECU) developed by FEV. The paper focuses on the vehicle set-up and performance in transient emission test cycles and under real world driving conditions. In addition, electrical energy management was considered to ensure an efficient power distribution.

   3. The tailored powertrain for 48 V – options for the gasoline engine – chance for future Diesel engines

      Wolfgang Schöffmann, Helfried Sorger, Michael Weissbäck, Thomas Pels, Carsten Kaup, Mario Brunner

      Abstract

      The next steps of fuel consumption legislation will require a combination of engine measures with various electrification measures, dependent on the vehicle segment, to reduce the energy demand targets of the vehicle. The introduction of 48V electrical architecture provides increased electric recuperation and limited electric driving at lower cost compared to full hybrid solutions, offering considerable fuel reduction potential in the WLTC.

      Current belt starter-generator systems (P0) already realise direct recuperation and torque boost functions. Additionally they can support a highly effective electrical supercharging system. More flexible powertrain architectures with a clutch to disconnect the engine form the driveline (P2,P3,P4) allow pure 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.

      The optimum balance of electrical and mechanical functions on the base engine and its periphery requires an application dependent evaluation with the aim of minimized overall system complexity and cost as well as added customer value.

      In previous papers [13, 14, 16] this had been evaluated for a gasoline engine application.

      In this paper, the electrical efficiency potential of the 48V E-Motor is compared in different architectures and dependent on the electrical power. Furthermore the effects of friction and power loss of electrified components are investigated in detail for the relevant driving conditions. The implementation of the accessary electrification has been investigated for a conventionally optimized gasoline and diesel engine in a Csegment vehicle with the aim of a tailored 48V base engine and focus on modular functional integration.

   4. Optimal hybrid gasoline engine – solutions for complex powertrains

      Christoph Danzer, Gerrit Albrecht, Mark Vallon, Günter Reimer, Wolfgang Wukisiewitsch

      Abstract

      To meet the many and various development targets in relation to CO₂, emissions, performance, comfort, weight and costs for 2025 and 2030, manufacturers are looking for the most sustainable scenarios in the context of fleet demands, modular systems and production costs. The powertrain plays a key role in this regard. Fundamental decisions have far-reaching consequences, and correcting those leads furthermore to an enormous effort. The complexity of the goals, demands and boundary conditions is so high that optimizing the powertrain’s components with conventional development methods is no longer sufficient.