The main combustion by-products of an automotive diesel engine are carbon-dioxide
(CO2), particulate matter (PM) and oxides of nitrogen (NOx). Engine designers are
challenged by the legal limits for PM and NOx reductions, especially as options are
limited. Exhaust after- treatment devices are being used as a means to meet emission
legislations. Another option, optimising the combustion process itself, has potential
for improved efficiency as well as reducing the regulated emission species. Studies
have confirmed this, by demonstrating that the in-cylinder flow conditions, which are
driven by fuel spray and piston bowl interaction, are critical for the combustion event.
Achieving emission reductions without compromising engine efficiency requires
improved understanding of fuel/gas mixing and pollutant formation mechanisms.
This improved understanding of the combustion system can be obtained through
mechanical, electrical/electronic and optical techniques. Optical techniques are often
preferred due to their non-intrusive nature.
|Date of Award||Apr 2015|