Search Results

The fuel injection in internal combustion engines plays a crucial role in the mixture formation, combustion process and pollutants' emission. Its correct modeling is fundamental to the prediction of an engine performance through a computational fluid dynamics simulation. In the first part of this work a tridimensional numerical simulation of a multi-hole’s injector, using ethanol as fuel, is presented. The numerical simulation results were compared to experimental data from a fuel spray injection bench test in a quiescent vessel. The break up model applied to the simulation was the combined Kelvin-Helmholtz Rayleigh-Taylor, and a sensitivity analysis of the liquid fuel penetration curve, as well on the overall spray shape was performed according to the model constants. Experimental spray images were used to aid the model tuning. The final configuration of the KH-RT model constants that showed best agreement with the measured spray was C3 equal to 0.5, B1, 7 and Cb, 0.

The use of torch ignition systems in spark-ignition engines represents an interesting option in the efforts to reduce pollutants emission and specific fuel consumption. Based on this idea, this paper presents a 3D model of a prechamber created for a spark-ignition engine and focuses on the numerical analysis of the fluid flow inside the modified chamber. This kind of analysis is very important once it allowed evaluating aspects like turbulence parameters, pressure inside the chamber and prechamber, fluid recirculation and a possible prechamber’s geometry for the engine. The studies were done in a four valve Single Cylinder Research Engine - SCRE. For the numerical modeling and fluid flow investigation it was used STAR-CD Software. The numerical results permitted to characterize the fluid flow in the modified engine and compare it with the standard engine, which showed significant differences and an interesting potential.