Imaging has long shown that under some highpressure
conditions, the presence of discrete twophase
flow processes becomes diminished. Under
such conditions, liquid injection processes transition
from classical sprays to dense-fluid jets, with
no drops present. When and how this transition
occurs, however, was not well understood until
recently. In this paper, we have summarized a
new theoretical description that quantifies the
effects of real fluid thermodynamics on liquid fuel
injection processes as a function of pressure at typical
Diesel engine operating conditions. We then
focused on the effects of real-fluid thermodynamics
and transport using the Large Eddy Simulation
(LES) technique. Analysis was performed using
the Engine Combustion Network (www.sandia.
gov/ECN) Spray-A case. LES was performed by
identically matching the operating conditions used
in the experiments. Results were analyzed with
emphasis placed on the state of the transient mixing
field prior to auto-ignition.