A Computer Code for Virtual Simulation of Diesel Fuel Spray Characteristics for Automotive Engines

Diesel fuel conservation will greatly help in increasing fuel economy and saving foreign exchange. Though many alternate fuels are being tried, diesel fuel will be the prime source of energy in the near future. So optimum utilization of diesel fuel will greatly help in achieving fuel conservation. Hence proper understanding of the diesel engine combustion mechanism is very much essential to achieve the fuel conservation. Though many experimental investigations have been tried in this direction, theoretical modeling and virtual simulation are helpful to understand the above said mechanism in an efficient way. In this work, a source computer code has been developed to virtually simulate the diesel fuel spray characteristics, which are predicted based on an integrated spray and combustion model considering ‘Fuel-Air mixing’ and ‘Droplet Vaporization’. The same code has been used to plot the virtually predicted results. The graphical representation were analyzed and discussed.

Based on the predicted results, it has been observed that the spray penetration decreases from 70mm to 30mm for a pressure rise of 30 bar, the Sauter Mean Radius increases with penetration and there is up to 2mm reduction in penetration for the swirl speed increase of 500-rpm. Also there was an increase in air entrainment rate of 0.002 kg/s and increase in mixture preparation rate of 0.004 kg/s for every 500 -rpm increase in swirl speed. In summary, it is concluded that the virtually predicted results were closer to the accepted test results and helpful for further investigations.