Comparison of theoretical and experimental diesel and DME injection spray characteristics

The objective of this research was to compare the spray penetration from a common rail injector using equations proposed in the literature to experimentally attained results, using diesel and dimethyl ether (DME) as fuels. The injection occurred in a chamber pressurized with nitrogen at injection pressures of 400 bar and 600 bar into ambient pressures of 12 bar, 16 bar and 18 bar. High speed images were recorded at 10 000 fps. Analysis of the results indicated that the models proposed by Wakuri et al. and Sazhin et al., at the same conditions, provided penetration values that were closest to the experimental values. In terms of the two models, it was found that the predicted depth of penetration of diesel fuel was, in general, not very well predicted. The DME showed close correlation with the both models at higher injection pressure and higher chamber pressure. The model proposed by Sazhin appears to produce somewhat better results for DME at the conditions reported in this research. The SMD values of DME were noted to be higher than those of diesel for the same conditions.

► Fuel injection tests were conducted using Diesel and DME in a pressurized chamber. ► Injection pressures of 400bar and 600bar were tested with both fuels. ► Theoretical penetrations were determined using models by Sazhin et al and Wakuri et al. ► At higher injection and ambient pressures DME approaches Sazhin more closely. ► A stable pressure trace of the rail pressure for DME was obtained.