Modern diesel engines operate under injection pressures
varying from 30 to 200 MPa and employ combinations
of very early and conventional injection timings to
achieve partially homogeneous mixtures. The variety of
injection and cylinder pressures results in droplet atomization
under a wide range of Weber numbers. The high
injection velocities lead to fast jet disintegration and secondary
droplet atomization under shear and catastrophic
breakup mechanisms. The primary atomization of the
liquid jet is modeled considering the effects of both infinitesimal
wave growth on the jet surface and jet turbulence.
Modeling of the secondary atomization is based
on a combination of a drop fragmentation analysis and a
boundary layer stripping mechanism of the resulting
fragments for high Weber numbers. The drop fragmentation
process is predicted from instability considerations
on the surface of the liquid drop. Validation of the model
has been performed by comparing the computational
results with experimental measurements from isolated
drops in shock tube experiments as well as with observations
from fully developed diesel sprays.