Impact of Future High Pressure Diesel Injection Systems on Noise and Emission Levels of Modern Combustion Processes

Authors

Dr.-Ing. U. Dohle, Dr.-Ing. M. Dürnholz, Dipl.-Ing. J.-O. Stein, Robert Bosch GmbH, Stuttgart

Year

2004

Print Info

Fortschritt-Berichte VDI, Reihe 12, Nr. 566

Summary

As a result of the excellent performance and fuel economy the number of diesel passenger car sales have been grown up continuously in Europe leading to a market penetration of more than 60% in some countries. This is mainly due to the innovations on combustion and injection system as a key system which allow to realize better driveability and comparable driving comfort compared to Otto passenger cars. To meet the stronger future emission limits as well as increased customer demands on acoustics new concepts have to be developed. For this reason Robert Bosch GmbH had been carried out detailed investigations to find out the influence of injection rate shaping on emission and noise behavior. As result an ideal injection rate shape was defined allowing to give up pilot injection in wide map ranges. Giving up pilot injection but optimize the injection rate shape during ignition delay and the diffusion flame leads to significant lower NOx- and soot emissions in combination with a favorable noise behavior. The results of these investigations have been used for the development of the 4th generation of Bosch Common rail systems like coaxial-vario-nozzle and the pressure amplified HADI system. In combination with new combustion concepts both systems will be improve significantly emission and noise behavior of future Diesel engines and thus supporting the Diesel market penetration.

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