Steffens, C., Korfer, T., Hanses, G., Rosplesch, A. et al., "Improvement of Comfort Aspects for High Efficiency Diesel Engines," SAE Technical Paper 2013-26-0119, 2013, doi:10.4271/2013-26-0119.
Besides an excellent driving performance and power output the reduction of CO2 emission is one of the main driver for the increasing distribution of modern diesel engines. Downsizing/downspeeding, friction reduction, new combustion processes and light weight engine architecture describe additional improvement potentials. Nevertheless, these development trends have a significant influence on the noise and vibration behavior of diesel engines. Therefore measures are also necessary to compensate these acoustic disadvantages. Within this publication the most important and efficient countermeasures are described and assessed.Combustion is still one of the dominant noise sources of a modern diesel engine. Diesel knocking is annoying and the combustion noise level is typically higher than for gasoline engines. In the midterm, cylinder pressure based control of pilot combustion and injection characteristic will become a promising approach as an extension of conventional, already established closed-loop combustion control algorithms to improve this situation. First investigations at FEV have demonstrated that a closed-loop control of the rate of heat release through multiple injections is able to reduce both, emissions and combustion noise.However, further measures are necessary to improve the overall NVH behavior of diesel engines. An optimized base engine architecture is essential in this context. On one hand, conceptual measures have to be introduced; on the other hand, a detailed layout of each component is necessary.