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In the last few years, almost every automotive OEM has announced the development of some sort of electric vehicles. Many of those have already been shown to the public, either as concept vehicles, or as pre-production demonstration vehicles. In order to support the development of this technology, FEV has, over the last 18 months, developed more than 20 different electric, or range-extended electric vehicles. All those vehicles are driving successfully on the road today, either as demonstration or fleet vehicles. The development of those vehicles was only possible through partnerships, and very close cooperation with key suppliers. In contrast to conventional powertrain technology, key components (e.g. battery, traction motor, electric HVAC, inverters) are not yet off-the-shelf technology and need further development and adaptation to the new vehicle concepts.

Measures for reducing engine friction within the powertrain are assessed in this paper. The included measures work in combination with several new technologies such as new combustion technologies, downsizing and alternative fuels. The friction reduction measures are discussed for a typical gasoline vehicle. If powertrain friction could be eliminated completely, a reduction of 15% in CO2 emissions could be achieved. In order to comply with more demanding CO2 legislations, new technologies have to be considered to meet these targets. The additional cost for friction reduction measures are often lower than those of other new technologies. Therefore, these measures are worth following up in detail.

Due to raising interest in diesel powered passenger cars in the U.S. in combination with a desire to reduce dependency on imported petroleum, there has been increased attention to the operation of diesel vehicles on fuels blended with biodiesel. One of several factors to be considered when operating a vehicle on biodiesel blends is understanding the impact and performance of the fuel on the emission control system. This paper documents the impact of the biodiesel blends on engine-out emissions as well as the overall system performance in terms of emission control system calibration and the overall system efficiency. The testing platform is a light-duty HSDI diesel engine with a Euro 4 base calibration in a 1700 kg sedan vehicle. It employs 2nd generation common-rail injection system with peak pressure of 1600 bar as well as cooled high-pressure EGR. The study includes 3 different fuels (U.S.

Raising interest in Diesel powered passenger cars in the United States in combination with the government mandated policy to reduce dependency of foreign oil, leads to the desire of operating Diesel vehicles with Biodiesel fuel blends. There is only limited information related to the impact of Biodiesel fuels on the performance of advanced emission control systems. In this project the implementation of a NOx storage and a SCR emission control system and the development for optimal performance are evaluated. The main focus remains on the discussion of the differences between the fuels which is done for the development as well as useful life aged components. From emission control standpoint only marginal effects could be observed as a result of the Biodiesel operation. The NOx storage catalyst results showed lower tailpipe emissions which were attributed to the lower exhaust temperature profile during the test cycle. The SCR catalyst tailpipe results were fuel neutral.

Regulated emissions, CO2-values, comfort, good driveability, high reliability and costs, this is the main frame for all future powertrain developments. In this frame, the diesel powertrain, not only for passenger cars, but also for commercial vehicle applications, faces some challenges in order to fulfil the future European and current US emission legislations while keeping the fuel consumption benefit, good driveability and an acceptable cost frame. One of these challenges is the varying fuel qualities of diesel fuel in different countries including different cetane number, volatility, sulphur content and different molecular composition. In addition to that in the future, more and more alternative fuels with various fuel qualities and properties will be launched into the market for economical and environmental reasons. At present, the control algorithms of the injection system applied in most diesel engines is open loop control.

PlugIn Hybrid Electric Vehicles (PHEV) offer the opportunity to experience electric driving without the risk of vehicle break-down due to a low battery charge state. Thus, PHEV's represent an attractive means of meeting future CO2-legislation. PHEV batteries must fulfill a divergent list of requirements: on the one hand, the battery must supply sufficient energy to ensure it can be driven an appropriate distance in EV-mode. On the other hand, even with a low state-of-charge (SOC), the battery must supply sufficient power to assist the engine in vehicle acceleration or to recuperate on deceleration. This leads to a compromise in terms of cell selection. Fundamentally, high energy cells cannot provide high charge and discharge rates and high power cells cannot provide sufficient energy.

In this study the fuel influence of several bio-fuel candidates on homogeneous engine combustion systems with direct injection is investigated. The results reveal Ethanol and 2-Butanol as the two most knock-resistant fuels. Hence these two fuels enable the highest efficiency improvements versus RON95 fuel ranging from 3.6% - 12.7% for Ethanol as a result of a compression ratio increase of 5 units. Tetrahydro-2-methylfuran has a worse knock resistance and a decreased thermal efficiency due to the required reduction in compression ratio by 1.5 units. The enleanment capability is similar among all fuels thus they pose no improvements for homogeneous lean burn combustion systems despite a significant reduction in NOX emissions for the alcohol fuels as a consequence of lower combustion temperatures.

Due to the complex powertrain layout in hybrid vehicles, different configurations concerning internal combustion engine, electric motor and transmission can be combined - as is demonstrated by currently produced hybrid vehicles ([1], [2]). At the Institute for Combustion Engines (VKA) at RWTH Aachen University a combination of simulation, Design of Experiments (DoE) and numerical optimization methods was used to optimize the combustion engine, the powertrain configuration and the operation strategy in hybrid powertrains. A parametric description allows a variation of the main hybrid parameters. Parallel as well as power-split hybrid powertrain configurations were optimized with regard to minimum fuel consumption in the New European Driving Cycle (NEDC). Besides the definition of the optimum configuration for engine, powertrain and operation strategy this approach offers the possibility to predict the fuel consumption for any modifications of the hybrid powertrains.

Based on the TurboDISI engine presented earlier [1], [2], a new Spray Guided Turbo (SGT) concept with enhanced engine performance was developed. The turbocharged engine was modified towards utilizing a spray-guided combustion system with a central piezo injector location. Higher specific power and torque levels were achieved by applying specific design and cooling solutions. The engine was developed utilizing a state-of-the-art newly developed charge motion design (CMD) process in combination with single cylinder investigations. The engine control unit has a modular basis and is realized using rapid prototyping hardware. Additional fuel consumption potentials can be achieved with high load EGR, use of alternative fuels and a hybrid powertrain. The CO2 targets of the EU (120 g/km by 2012 in the NEDC) can be obtained with a mid-size vehicle applying the technologies presented within this paper.

Representative Interactive Flamelets (RIF) have proven successful in predicting Diesel engine combustion. The RIF concept is based on the assumption that chemistry is fast compared to the smallest turbulent time scales, associated with the turnover time of a Kolmogorov eddy. The assumption of fast chemistry may become questionable with respect to the prediction of pollutant formation; the formation of NOx, for example, is a rather slow process. For this reason, three different approaches to account for NOx emissions within the flamelet approach are presented and discussed in this study. This includes taking the pollutant mass fractions directly from the flamelet equations, a technique based on a three-dimensional transport equation as well as the extended Zeldovich mechanism. Combustion and pollutant emissions in a Common-Rail DI Diesel engine are numerically investigated using the RIF concept. Special emphasis is put on NOx emissions.

In this paper a new approach is presented to evaluate the combustion behaviour of homogeneous gasoline engines by predicting burn delay and -duration in a way which can be obtained under the time constraints of the development process. This is accomplished by means of pure in-cylinder flow simulations without a classical combustion model. The burn delay model is based on the local distribution of the turbulent flow near the spark plug. It features also a methodology to compare different designs regarding combustion stability. The correlation for burn duration uses a turbulent characteristic number that is obtained from the turbulent flow in the combustion chamber together with a model for the turbulent burning velocity. The results show good agreement with the combustion process of the analyzed engines.

The finite nature and instability of fossil fuel supply has led to an increasing and enduring investigation demand of alternative and regenerative fuels. The Institute for Combustion Engines at the RWTH Aachen University carried out an investigation program to explore the potential of tailor made fuels to reduce engine-out emissions while maintaining engine efficiency and an acceptable noise level. To enable optimum engine performance a range of different hydrocarbons having different fuel properties like cetane number, boiling temperature and different molecular compositions have been investigated. Paraffines and naphthenes were selected in order to better understand the effects of molecular composition and chain length on emissions and performance of an engine that was already optimized for advanced combustion performance. The diesel single-cylinder research engine used in this study will be used to meet Euro 6 emissions limits and beyond.

Increased demand for highly fuel efficient propulsion systems drives the engine development community to develop advanced technologies allowing improving the overall thermal efficiency while maintaining low emission levels. In addition to improving the thermal efficiencies of the internal combustion engine itself the developments of fuels that allow improved combustion as well as lower the emissions footprint has intensified recently. This paper will describe the effects of five different fuel types with significantly differing fuel properties on a state-of-the-art light-duty HSDI diesel engine. The fuels cetane number ranges between 26 and 76. These fuels feature significantly differing boiling characteristics as well as heating values. The fuel selection also contains one pure biodiesel (SME - Soy Methyl Ester). This study was conducted in part load and full load operating points using a state of the art HSDI diesel engine.

A broad range of diesel, kerosene, and gasoline-like fuels has been tested in a single-cylinder diesel engine optimized for advanced combustion performance. These fuels were selected in order to better understand the effects of ignition quality, volatility, and molecular composition on engine-out emissions, performance, and noise levels. Low-level biofuel blends, both biodiesel (FAME) and ethanol, were included in the fuel set in order to test for short-term advantages or disadvantages. The diesel engine optimized in Part 1 of this study included cumulative engine hardware enhancements that are likely to be used to meet Euro 6 emissions limits and beyond, in part by operating under conditions of Homogeneous Charge Compression Ignition (HCCI), at least over some portions of the speed and load map.

During the past years, there has been an increasing tendency to seriously question and break up old and ingrained structures in combustion engine testing. The reason for this is the continuously increasing number of engine and vehicle variants and a variety of applications resulting from it, which significantly push up development costs and times when carrying out the classical testing patterns. The following article by FEV Motorentechnik GmbH introduces a comprehensive test methodology for purposeful endurance testing of modern drive units (in particular from the fields of passenger cars and commercial vehicles). The procedure and the testing philosophy are explained in detail, illustrated by a concrete development example.

Effects of six different fuels on low temperature premixed compression ignition (PCI) combustion were experimentally investigated in this paper with a light-duty HSDI engine. The PCI combustion concept reduces NOx and smoke emissions simultaneously by low temperature and premixed combustion, respectively. To achieve low temperature and premixed combustion, the ignition delay is prolonged and the injection duration is shortened. Six fuels were chosen to examine the influence of cetane number (CN) and other fuel properties on low temperature PCI combustion. The fuel selection also included a pure Gas- to-Liquid (GTL) fuel and a blend of base diesel and 20% soy based biodiesel (B20). Fuel effects were studied over a matrix of seven part load points in the low temperature combustion mode. The seven part load points were specified by engine speed (RPM) and brake mean effective pressure (BMEP).

This paper describes an alternative catalyst aging process using a hot gas test stand for thermal aging. The solution presented is characterized by a burner technology that is combined with a combustion enhancement, which allows stoichiometric and rich operating conditions to simulate engine exhaust gases. The resulting efficiency was increased and the operation limits were broadened, compared to combustion engines that are typically used for catalyst aging. The primary modification that enabled this achievement was the recirculation of exhaust gas downstream from catalyst back to the burner. The burner allows the running simplified dynamic durability cycles, which are the standard bench cycle that is defined by the legislation as alternative aging procedure and the fuel shut-off simulation cycle ZDAKW. The hot gas test stand approach has been compared to the conventional engine test bench method.

The technology used in hybrid vehicle concepts is significantly different from conventional vehicle technology with consequences also for the noise and vibration behavior. In conventional vehicles, certain noise phenomena are masked by the engine noise. In situations where the combustion engine is turned off in hybrid vehicle concepts, these noise components can become dominant and annoying. In hybrid concepts, the driving condition is often decoupled from the operation state of the combustion engine, which leads to unusual and unexpected acoustical behavior. New acoustic phenomena such as magnetic noise due to recuperation occur, caused by new components and driving conditions. The analysis of this recuperation noise by means of interior noise simulation shows, that it is not only induced by the powertrain radiation but also by the noise path via the powertrain mounts. The additional degrees of freedom of the hybrid drive train can also be used to improve the vibrational behavior.

Within the Cluster of Excellence “Tailor-Made Fuels from Biomass” at RWTH Aachen University, the Institute for Combustion Engines carried out an investigation program to explore the potential of future biofuel components in Diesel blends. In this paper, thermodynamic single cylinder engine results of today's and future biofuel components are presented with respect to their engine-out emissions and engine efficiency. The investigations were divided into two phases: In the first phase, investigations were performed with rapeseed oil methyl ester (B100) and an Ethanol-Gasoline blend (E85). In order to analyze the impact of different fuel blends, mixtures with 10 vol-% of B100 or E85 and 90 vol-% of standardized EN590 Diesel were investigated. Due to the low cetane number of E85, it cannot be used purely in a Diesel engine.

Since the CO2 emissions of passenger car traffic and their greenhouse potential are in the public interest, natural gas (CNG) is discussed as an attractive alternative fuel. The engine concepts that have been applied to date are mainly based upon common gasoline engine technology. In addition, in mono-fuel applications, it is made use of an increased compression ratio -thanks to the RON (Research Octane Number) potential of CNG-, which allows for thermodynamic benefits. This paper presents advanced engine concepts that make further use of the potentials linked to CNG. Above all, the improved knock tolerance, which can be particularly utilized in turbocharged engine concepts. For bi-fuel (CNG/gasoline) power trains, the realization of variable compression ratio is of special interest. Moreover, lean burn technology is a perfect match for CNG engines. Fuel economy and emission level are evaluated basing on test bench and vehicle investigations.