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The requirement of reducing worldwide CO₂ emissions and engine pollutants are demanding an increased use of bio-fuels. Ethanol with its established production technology can contribute to this goal. However, due to its resistive auto-ignition behavior the use of ethanol-based fuels is limited to the spark-ignited gasoline combustion process. For application to the compression-ignited diesel combustion process advanced ignition systems are required. In general, ethanol offers a significant potential to improve the soot emission behavior of the diesel engine due to its oxygen content and its enhanced evaporation behavior. In this contribution the ignition behavior of ethanol and mixtures with high ethanol content is investigated in combination with advanced ignition systems with ceramic glow-plugs under diesel engine relevant thermodynamic conditions in a high pressure and temperature vessel.

In view of limited crude oil resources, alternative fuels for internal combustion engines are currently being intensively researched. Synthetic fuels from natural gas offer a promising interim option before the development of CO2-neutral fuels. Up to a certain degree, these fuels can be tailored to the demands of modern engines, thus allowing a concurrent optimization of both the engine and the fuel. This paper summarizes investigations of a Gas-To-Liquid (GTL) diesel fuel in a modern, post-EURO 4 compliant diesel engine. The focus of the investigations was on power output, emissions performance and fuel economy, as well as acoustic performance, in comparison to a commercial EU diesel fuel. The engine investigations were accompanied by injection laboratory studies in order to assist in the performance analyses.

Current simulation tools for the investigation of the dynamic system response as well as for the component stresses on the basis of multi-body and finite-element techniques are integral part of today's powertrain development efforts. These tools are typical used for the analysis and optimization of shafts, clutches, chain/belt drives, bearings, levers, brackets, housings and many other components. An exception is made by gears which today are still frequently investigated by the help of semi-empirical methods based on DIN, ISO, AGMA and the specific knowledge base of well experienced developers. The main difficulty is that the gears are rolling off via large contact surfaces with complex nonlinear mechanical contact properties. Within the scope of research work FEV developed a new method for the analysis and optimization of gear drives based on comercial multi-body and finite-element software platforms.

Due to the future application of combustion engines in small and hybrid vehicles, the demand for high efficiency with low mass and compact engine design is of prime importance. The diesel engine, with its outstanding thermal efficiency, is a well suited candidate for such applications. In order to realize these targets, future diesel engines will need to have increasingly higher specific output combined with increased power to weight ratios. This is therefore driving the need for new designs of 3 and/or 4 cylinder, small bore engines of low displacement, sub 1.5l. Recent work on combustion development, has shown that combustion systems, ports, valves and injector sizes are available for bore sizes down to 65 mm.

In the recent years, it has become obvious that one of the main fields of interest in alternate fuels is the public transportation sector. Natural Gas seems to be advantageous. It is available and environmentally friendly, even if the greenhouse effect of methane is considered. The operation range of vehicles running on CNG (Compressed Natural Gas) is poor due to the large pressure vessels, but in case of urban buses with low daily mileage this is acceptable. On the other hand, the use of an environmentally friendly fuel is favorable especially in urban areas. Although there are some advantages of Natural Gas, diesel buses dominate the market. The reason is the better part-load fuel efficiency of the Diesel principle which is superior to the Otto-cycle due to the absence of engine throttling. The efficiency levels of Spark-Ignition (SI) -type, Lean Burn Natural Gas engines are quite comparable to diesel engines during full load conditions.

Passenger car customer expects both: low interior noise level and a sound quality, adapted to vehicle driving condition. The latter should be based upon a comfortable sound character without outstanding noise effects. One of the very unpleasant noise characteristics is roughness, also called rap noise or rumbling noise. Beside intake noise and powertrain structure bending, the dynamic crank train behaviour is one of the potential origins of a rough noise pattern. Material properties of the crankshaft and the layout of crankshaft damper can influence roughness as well as the crank train clearances. Subjects of this study, which was performed on a 4-cylinder spark-ignition (SI) engine, were the identification and objectivation of a specific noise concern which occurred during vehicle acceleration. Aim was to evaluate the noise concern sensitivity to the crank train clearances and to define optimum clearance ranges for noise quality improvement.

Today, natural gas engines for stationary and vehicular applications are not only faced with stringent emission legislation, but also with increasing requirements for power density and efficient fuel consumption. For vehicular use, downsizing is an advantageous approach to lowering on-road fuel consumption and making gas engines more competitive with their diesel counterparts. In SI-engines, the power density at a given compression ratio is limited by knocking, or NOx emissions. A decrease in compression ratio, lowering both NOx emissions and the risk of knocking combustion, increases fuel consumption. An increase in air-fuel-ratio, required to avoid knocking at higher thermal loading, increases boost pressure, HC and CO emissions, and mechanical loading and causes the danger of misfiring. As a result, the performance of the latest production gas engines for vehicles remains at a BMEP of 18…20 bar with a NOx emission level of 2…5 g/kWh.

Increasing shortages of energy resources as well as emission legislation is increasing the pressure to develop more efficient, environmentally friendly propulsion systems for vehicles. Due to its more than 125 years of history with permanent improvements, the internal combustion engine (ICE) has reached a very high development status in terms of efficiency and emissions, but also drivability, handling and comfort. Therefore, the IC engine will be the dominant propulsion system for future generations. This paper gives a survey on the present technical status and future prospects of internal combustion engines, both CI and SI engines, also including alternative fuels. In addition a brief overview of the potential of currently intensely discussed hybrid concepts is given.

Thermal management describes measures that result in the improved engine or vehicle operation in terms of energetics and thermo mechanics. In this context the involvement of the entire power train becomes more important as the interaction between engine, transmission and temperature sensitive battery package (of hybrid vehicles or electric vehicles with range extender) or the utilization of exhaust gas thermal energy play a major role for future power train concepts. The aim of thermal management strategies is to reduce fuel consumption while simultaneously increasing the comfort under consideration of all temperature limits. In this case it is essential to actively control the heat flow, in order to attain the optimal temperature distribution in the power train components.