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Diesel fuel sprays were visualized in the main chamber of a single-cylinder, air-cooled prechamber diesel engine. The experiments were conducted while the piston was positioned at various locations with respect to the ceiling of the main chamber. A ceramic disk with an embedded nickel-chrome heating coil was bolted on the top of the piston. The temperature of the ceramic surface was varied in the 300-500°C range. It was observed that the impinging fuel spray was associated with the formation of a boundary zone (B.Z.) between the hot surface of the piston and the turbulent flow in the main chamber. The spray appeared to have been deflected away from the piston by this boundary zone. It was found that the thickness of this zone increases with increasing both the piston temperature and the chamber height, and decreases with increasing the quantity of fuel per injection. Performance tests were conducted on an operating single-cylinder, air-cooled prechamber diesel engine.

A general model, which uses general equations to determine the thermophysical properties of fuels in terms of temperature, molecular mess, critical constants and molecular structure, has been developed to describe the evaporation characteristics of multicomponent fuel droplets according to both the shell and ideal solution postulates. Upon applying this model to alcohol-dodecone mixtures, the feasibility of such mixtures for heterogeneous combustion systems has been assessed, and feasibility charts have been developed.

Dynamic modeling of a diesel injection system is imperative to identify the forces applied to the system's elements and determine the conditions under which the system will be stable. The results of dynamic modeling are especially important for injection systems with different operating modes. This work uses a five-degree-of-freedom system to represent a diesel unit injector. The Bondgraph Method was used for formulating the kinematic and dynamic equations. The inputs to the system were the velocity of the cam follower and the pressure force exerted by the fuel on the plunger. The coefficients of the system's characteristic equation were then determined. Routh's criteria were considered to identify the region of stability for the unit injector.

A study was conducted on a direct-injection, single-cylinder, research-type diesel engine to determine the effect of adding ethanol to diesel fuel on the ignition delay period. The tests covered the whole range of ethanol-DF2 blends: from 100% ethanol to 100% DF2. The test parameters were: the ethanol content, the intake-air properties, and the equivalence ratio. The ignition delay was measured by detecting the beginning of injection and the occurrence of a detectable pressure rise. The present results show that, for ethanol-DF2 blends, the pressure-rise delay decreases by increasing both the intake-air pressure and the intake-air temperature, and increases by increasing the ethanol content in the blend. Ignition delay correlations were developed in terms of air temperature, air pressure, and ethanol volumetric fraction. The global activation energy was determined and correlated with the cetane number for each blend.