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The feasibility of using kerosene fuel in a spark ignited two-stroke engine was investigated. Primary effort was directed at comparing kerosene fueled performance to gasoline fueled performance and to overcoming cold starting problems with kerosene. The single cylinder research engine had fuel injection upstream of the reed valve and used loop scavenging. A vortex pneumatic atomizer was used to reduced the droplet size. The results of this study indicate that the vortex pneumatic atomizer helps reduce poor performance of the engine when using kerosene fuel. A method to overcome the cold starting problem with kerosene fuel has been developed, which involves heating the atomization air during start up.

The fluid flow characteristics inside compound silicon micro machined port fuel injector nozzles were analyzed through the use of computational fluid dynamics (CFD). This study was undertaken in order to gain a better understanding of the fluid mechanics taking place in the compound orifice plate. In addition, the calculated computational results will be used to predict the fuel spray patterns and sauter mean diameters of the sprays. The influence of orifice plate geometry on calculated turbulent kinetic energies and fuel spray patterns was also studied and will be discussed. The results of this investigation indicate that the fluid flow characteristics inside the compound silicon micro machined port fuel injector nozzle are influenced by the geometries of the compound orifice plate, and that the flow characteristic inside the orifice plate effect the type of spray produced by the injector.

Lean limit characteristics of a pneumatic port fuel injection system is compared to a conventional port fuel injection system. The lean limit was based on the measured peak pressure. Those cycles with peak pressures greater than 105 % of the peak pressure for a nonfiring cycle were counted. Experimental data suggests that there are differences in lean limit characteristics between the two systems studied, indicating that fuel preparation processes in these systems influence the lean limit behaviors. Lean limits are generally richer for pneumatic fuel injection than those for conventional fuel injection. At richer fuel-to-air ratios the pneumatic injector usually resulted in higher torques. A simple model to estimate the evaporation occurring in the inlet manifold provided an explanation for the observed data.

Increasingly stringent emissions regulations and customer demands for high efficiency and smooth performance demand highly accurate control of the air-fuel ratio of automotive spark-ignition engines. Electronic port fuel injection provides the necessary control by adding a precise quantity of fuel for a given amount of air drawn in by the engine. Ideally, the metered fuel will consist only of fine droplets and vapor. In reality, the fuel spray impinges upon the walls of the intake port, creating a liquid fuel film. The fundamentally different transport mechanisms of the liquid fuel compared to vapor or fine droplets greatly complicates; the analysis of the fuel delivery system. Past research has provided models of fuel film dynamics in intake ports of port-fuel-injected engines, yet to date no practical method of measuring fuel films has been presented.