The objective of this project is to investigate how fuel technology can be exploited in combination with the advances in diesel engine design in an optimum strategy to further reduce diesel pollutant emissions.
This programme investigates the following issues relating to the influence of diesel fuel properties on pollutant formation : - the role of the fuel aromatics content, particularly the bi- and tri-cyclic aromatics component, and the importance of this in correlations of particulate emissions with fuel density; - the use of simplified test procedures to predict the sooting tendencies of fuels in diesel engines; - the effects of an oxygenate component on particulate and gaseous emissions; - the application of combustion and engine modelling in rationalising the influences of fuel characteristics and engine design features on particulate emissions.
The work programme consists of four tasks : the selection, formulation and supply of the test fuels; laboratory experimental measurements of the formation of polycyclic aromatic hydrocarbons (PAH) and soot in flame conditions; measurements of soot and gaseous pollutant yields in research and current production commercial diesel engines; and modelling of the chemistry of soot formation and related physical processes, leading to a parametric wholecylinder diesel engine pollutant model. These tasks are subdivided into a series of work packages.
The matrix of test fuels is common to all of the experimental investigations. The reference fuel has a mono-aromatics fraction typical of European diesel, but very low higher aromatics content. The first batch of test fuels covers controlled additions of by-cyclic aromatic components derived from light cycle oil, and of a tri-cyclic aromatic dopant. The cetane number of the fuels will be nearly constant, and sulphur <0.05%. The second batch includes one fuel with an oxygenate component (diglyme). The remaining formulations are designed to distinguish the effects of polyaromatics content from those due to density changes. Eight fuel formulations will be investigated.
The laboratory experiments provide detailed data on the kinetics and yields of PAH and soot in combustion of the test fuels under controlled conditions. The three work packages cover laser optical measurements in premixed laminar flames; sooting tendency measurements in diffusion flames; and optical measurements of diesel spray combustion in a high pressure cell.
Funding SchemeCSC - Cost-sharing contracts
TW16 7LN Sunbury On Thames
UB8 3PH Uxbridge
20068 Peschiera Borromeo Milano
69360 Saint-symphorien-d'ozon (Solaize)