Performance of a Heavy Duty DME Engine - the Influence of Nozzle Parameters on Combustion and Spray Development

DME was tested in a heavy duty diesel engine and in anoptically accessible high-temperature and pressurespray chamber in order to investigate and understandthe effect of nozzle parameters on emissions,combustion and fuel spray concentration.The engine study clearly showed that smaller nozzleorifices were advantageous from combustion, efficiencyand emissions considerations. Heat release analysisand fuel concentration images indicate that smallerorifices result in higher mixing rate between fuel and airdue to reductions in the turbulence length scale, whichreduce both the magnitude of fuel-rich regions and thesteepness of fuel gradients in the spray, which enablemore fuel to burn and thereby shorten the combustionduration