Part I: Effect of Nitric Oxide and Other Diluents on Cold Starting, Combustion Instability, and White Smoke Emissions in Diesel Engines. Part II: autoignition, Combustion Instability and White Smoke Under Transient Conditions With JP-8.

摘要

This report covers an investigation aimed at developing electronic control strategies to improve the cold startability of diesel engines for military, dual-use and hybrid electric vehicles. The emphasis is on the analysis the processes that affect the cranking and acceleration modes during starting. The analysis indicated that NO present in the residual and recirculated gases has on effect on the order or the activation energy of the global autoignition reactions. The mathematical models developed for the two modes are able to determine the zones of misfiring, the number of cranking cycles and the causes of misfiring after firing, known as combustion instability. Furthermore, the research identified the strategy needed to reduce combustion instability. Also, the models developed in this work showed very clearly that the Cetane number is not a good indicator of the startability of the engine, and that fuel volatility plays a major part in the success of the autoignition process. In this regard JP-8 proved to be a better fuel that DF2, as far as the number of cranking cycles. However, its combustion is unstable if compared with DF2. The results indicated that the problems with cold starting of diesel engines with JP-8 are caused by the fuel injection strategy used in the commercial engines.