Search Results

Increasing shortages of energy resources as well as emission legislation development is increasing the pressure to develop more efficient, environmentally friendly propulsion systems for vehicles. Alternatives such as fuel cell systems or hybrid propulsion are in discussion or have already been introduced. This paper gives a survey on the present technical status of internal combustion engines, hybrid concepts and current fuel cell vehicles. Different solutions will be presented, so that an evaluation of advantages and drawbacks can be given. The further potentials of each concept, as well as combinations of different systems are discussed, and an outlook into the future is given.

This paper describes the performance of a new, catalytically acting cerium-based fuel additive in relation to particulate trap regeneration quality, trap filtration efficiency, particle size distribution and fate of additive under steady-state engine operation conditions. The impact of the cerium fuel additive is compared to ferrocene respectively copper based fuel additives. The cerium-based fuel additive DPX6 lower the ignition temperature down to 200 °C. Frequent, so-called quasi-continuous, and smooth regenerations are induced by the cerium fuel additive in that temperature range. Thus, the regeneration quality is quite different to the stochastic and rapid oxidation known from ferrocene and copper. Out of this, the thermal stress with cerium fuel additive will be lower even when regenerations start at comparable high trap loading.

Modern passenger car engines are designed to operate at increasingly higher rated engine speeds with more internal parts (multi-valve engines) requiring lubrication. There is a higher probability for the oil quality to deteriorate due to an unfavorably high level of oil aeration. The high oil aeration can cause hydraulic lash adjuster misfunction and connecting rod bearing failure. This paper presents results of recent research and development work concerning the occurence of oil aeration within the lubricant system of modern combustion engines. In particular, the work has concentrated on the following: How oil aeration affects engine operation How cavitation occurs in the supply bore to the connecting rod bearings What causes air entrainment in lubricants

Currently, throughout the world combustion engine development is influenced by two primary concerns. First is the increasing concern for global warming, and second is the concern over particulate and oxides of nitrogen emissions, each of which affect the environment and human health because of the particles' toxicity and ground level ozone production, respectively. To address the global warming issue, in late 1997, various nations approved the Kyoto Protocol to reduce CO2 emissions because of its identified contribution to the greenhouse effect. The Diesel engine is the most efficient power plant for mobile and stationary purposes and, thus, Diesel engines are considered to be one alternative to gasoline engines to reduce fuel consumption and, thus, CO2 emissions. To address the emission concerns, the European Community and the U.S. Environmental Protection Agency (EPA) proposed emissions standards prescribing substantial reductions of NOX and PM emissions [1,2]1.