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International Journal of Rotating Machinery
Volume 2008, Article ID 175956, 13 pages
http://dx.doi.org/10.1155/2008/175956
Research Article

Possibilities of Simultaneous In-Cylinder Reduction of Soot and Emissions for Diesel Engines with Direct Injection

Institute of Reciprocating Engines, University of Karlsruhe (TH), Kaiserstraße 12, 76870 Karlsruhe, Germany

Received 7 April 2008; Accepted 26 June 2008

Academic Editor: Toshinori Watanabe

Copyright © 2008 U. Wagner et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Up to now, diesel engines with direct fuel injection are the propulsion systems with the highest efficiency for mobile applications. Future targets in reducing -emissions with regard to global warming effects can be met with the help of these engines. A major disadvantage of diesel engines is the high soot and nitrogen oxide emissions which cannot be reduced completely with only engine measures today. The present paper describes two different possibilities for the simultaneous in-cylinder reduction of soot and nitrogen oxide emissions. One possibility is the optimization of the injection process with a new injection strategy the other one is the use of water diesel emulsions with the conventional injection system. The new injection strategy for this experimental part of the study overcomes the problem of increased soot emissions with pilot injection by separating the injections spatially and therefore on the one hand reduces the soot formation during the early stages of the combustion and on the other hand increases the soot oxidation later during the combustion. Another method to reduce the emissions is the introduction of water into the combustion chamber. Emulsions of water and fuel offer the potential to simultaneously reduce and soot emissions while maintaining a high-thermal efficiency. This article presents a theoretical investigation of the use of fuel-water emulsions in DI-Diesel engines. The numerical simulations are carried out with the 3D-CFD code KIVA3V. The use of different water diesel emulsions is investigated and assessed with the numerical model.