buletinul institutului politehnic din iaşi - Universitatea Tehnică ...

118 Eugen Rusu et al.
in PM emission applied to diesel engine might also be applied to gasoline
engines in the near future. In addition, PM has been found to have adverse
effects on human health, especially for the smaller particles, since they have
higher deposition efficiency in the human respiratory system. SI engines have
been found to be the main sources for fine or ultrafine particles.
In order to meet new requirements for emission reduction and fuel
economy a variety of concepts are available for gasoline engines. In the recent
past new ways have been found using alternative fuels and fuel combinations to
reduce costs of engine function and fuel consumption.
The presented concept for a SI-engine consists of combined injection of
gasoline and hydrogen. A hydrogen enriched gas mixture is being injected
additionally to gasoline into the engine.
2. Literature Review of Past Numerical Simulation
Computer simulation has been always a way to overcome the costs of an
experimental study. With the help of the simulation researchers could facilitate
the development of the engines. For the simulation of the thermodynamic
processes inside the cylinder with hydrogen enrichment not many studies have
been done.
G. Fontana from the University of Cassino has conducted a numerical
investigation using a computational model, suitably developed in order to
predict the combustion process of dual fuel mixtures. This model is based on
the KIVA3-V code (Amsden et al., 1989), (Amsden, 1997) and was tested for
simulating the behavior of the engine fueled with gasoline-hydrogen mixtures.
To predict the thermal NO formation the Zeldovich kinetic model has been
used. Tests were done at a wide-open throttle with several equivalence ratios of
both hydrogen-air mixtures and gasoline-air mixtures (Fontana et al., 2002).
The computational analysis has marked the possibility of operating with high air
excess (lean and ultra lean mixtures) without a performance decrease but with
great advantages on pollutant emissions and fuel consumption. The results have
shown a reduction of NOx and CO2 emissions. The utilization of hydrogen as an
additive to a gasoline engine permits reducing the global gasoline consumption,
measured on the reference engine, to the gasoline consumption calculated
considering both gasoline injection and hydrogen production.
Another work regarding the numerical simulation was made by Maher
Abdul and Haroun Abdul (Abdul-Resul & Abdul-Kadim, 1998) from the
University of Babylon. They used a detailed model to simulate a four stroke
cycle of a spark ignition engine fueled with hydrogen-gasoline. The engine
performance parameters have been improved when operating the gasoline S.I.E.
with dual addition. The results of the study were promising. It has been found
that 4% of hydrogen causes a 30% reduction in CO emissions, a 27% reduction
in NOx, emissions a 34% reduction in specific fuel consumption and increase in
the thermal efficiency and output power by 5 and 4%.