Published 12 issues per year
ISSN Print: 1044-5110
ISSN Online: 1936-2684
Indexed in
ATOMIZATION AND EVAPORATION OF DIESEL SPRAYS IN HIGH-PRESSURE AND HIGH-TEMPERATURE ENVIRONMENTS
ABSTRACT
The influence of fuel pressure on diesel spray evolution into a quiescent environment at two temperatures (300 and 800 K) has been analyzed by means of a laser light scattering technique. Two-dimensional measurements have been made of scattering intensity and its polarization state on cross sections of the spray. The theoretical and experimental aspects of the technique and the interpretation of the measured quantities are presented. The results indicate that a wide variation of the conditions of fuel injection into a room-temperature environment (fuel peak pressure from 500 to 1400 bar) does not change the liquid surface area significantly between 7 and 14 mm from the nozzle. However, the same variation of fuel pressure influences the spray evolution very much in the same spatial region for injections into a high-temperature environment. In this case a high injection pressure (peak pressure of 1400 bar) results in an increase of the liquid surface area along the spray, whereas a relatively low pressure (peak pressure of 500 bar) results in a decrease. Some reasonable explanations of this behavior are discussed, considering the possible effects due to atomization, evaporation, coalescence, turbulent dispersion, and inertial evolution of the spray.