Progressing needs for prompt cold start of direct injection Diesel engines is the motivation behind this study. Authors have examined the autoignition and combustion processes in the early firing cycles of the engine and proposed a strategy to reduce the cranking period and the white smoke emissions. The concept is to accelerate the preparation of the combustible mixture during the cranking process. This is achieved by splitting the injected fuel in two parts and controlling its timing. The duration of the first injection is limited such that the spray penetrates through the combustion chamber and evaporates before it reaches the walls. The dwell between the two injections is adjusted to allow time for the first spray to mix with the fresh charge, form a combustible mixture and start producing the autoignition radicals. The second part would evaporate and autoignite by reacting with the radicals before it reaches the cool walls. The strategy is verified on a 1.2 L Ford Diata Diesel engine equipped with a first generation common rail fuel injection system. The cycle resolved hydrocarbons, and NOx emissions are measured by high response detectors. In addition, the mass and constituents of the white smoke are measured. All the experiments for this paper have been conducted after the engine has been soaked at the normal room temperature for at least eight hours. The results showed that there is an optimum strategy for the split injection that would minimize the cranking period and white smoke emissions.

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