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A new diesel fuel additive formulation is described which features reduced particulate emissions versus conventional diesel fuel. This new additive formulation contains a unique combustion improver that provides immediate and sustained reductions in particulate emissions and black smoke. Extensive testing of reduced black smoke performance was conducted with buses, trucks, vans, taxis and passenger cars in the U.K., France, Singapore, Hong Kong, New Zealand, Japan, and the U.S. An average immediate reduction in black smoke of 22% (up to 80%) was found for all vehicles when tested with additized versus unadditized fuel. Immediate reductions in particulate emissions were 16% on average (up to 30%) with the additized versus base fuel in light-duty vehicles (ECE 15 + EUDC testing) and heavy-duty engines (ECE R49 testing). Engine durability and performance tests showed no detrimental effect with the additized diesel fuel.

In this paper we present photographic and pressure data that describe the autoignition and combustion processes of transient fuel sprays under diesel-like conditions. The results were obtained in a constant-volume vessel that allowed complete optical access to the diesel spray ignition/combustion process. The combination of complete optical access and schlieren/luminosity visualization presents a unique view of the spray. From the data, a narrative of the features of diesel spray autoignition and combustion is constructed. Comparison of events at different gas-phase temperatures shows the effect of shifting the chemical induction time relative to the fluid mechanic transport time. The data show that a key feature of the autoignition process is the formation and shedding of fuel eddies along the edges of the spray jet. These eddies provide an environment conducive to chemical reaction, without the disruptive effects of the spray core fluid mechanics.