The introduction of the high-pressure fully
electronic-controlled injection systems has opened a number of new
possibilities to optimize diesel engine performance and to reduce
pollutant emissions. However greater research efforts are required
to meet future European emission legislation.
The control of the combustion process, which determines to a
large extent the amount of pollutant emissions, requires primarily
an understanding of its physics and chemistry as well as the
capability to modify one or more of the interdependent process
parameters in a given direction. Since many parameters have to be
considered, a combined experimental-numerical approach is
required.
In this context, the research group of the University of Rome
"Tor Vergata", which has developed a multidimensional
code for diesel engines simulation based on the KIVA 3V code, and
the research group of the University of Perugia, which has built a
laboratory for the characterization of diesel and SI injection
systems and sprays, have been collaborating for many years.
The implemented models in the multidimensional code enable full
3D computation of both gas and fuel spray dynamics to be made,
including atomization, vaporization, autoignition and combustion.
However, spray development, mixture preparation and combustion
depend on the fuel injection system characteristics and actual
operating conditions. Therefore, modelling of the fuel injection
system is essential to correctly predict all those parameters
involved in the fuel injection, which are still often considered as
constant input data in 3D simulations.
In this paper a 1D model, built in the AVL HYDSIM environment,
of the CR injection system of the University of Perugia laboratory
is presented and reliability of numerical results is tested through
a comparison with experimental data. Then, 3D simulations of diesel
spray development are performed coupling the 1D model of the
injection system to the multi-dimensional code.