A Study on Practical Utilization of Diesel Combustion Calculation

(A Series of Studies for Automatic Diesel Engine Adaptation)

抄録

It is much more important these days to utilize CAE techniques to shorten an engine development period and reduce manpower. These advantages surely bring competitiveness for developing new engines. The authors have been developing a diesel combustion calculation code based on KIVA-Waseda. So far, the calculation code is already equipped with the Hiroyasu-NSC(Nagle and Strickland-Constable) model for soot emission and the extended Zeldovich mechanism for NO(nitrogen monoxide) emission. Then aiming to utilize the calculation code on engine adaptation works to meet exhaust emission standards, following four items were studied. The first was that the detailed reaction model was modified in order to improve ignition delay estimations. The second was that the chemical reaction calculation speed was increased with two types of unique algorithm. The third was that a calculation system with auto-calculation software and analysis software was prepared to obtain NOx-soot trade-off curves easily, and the fourth was that a prompt-NO model was added to the detailed chemical reaction model to improve NO estimation at low power and high EGR operation conditions. The details of these four studies are described and a series of the calculation measures to obtain a NOx-soot trade-off curve is shown in this paper.