  The need for improved engine efficiencies has motivated the development of
high-pressure combustion systems, in which operating conditions achieve and
exceed critical conditions. Associated with these conditions are large
thermodynamic gradients and strong variations in transport properties as the
fluid undergoes mixing and phase transition. Accurately simulating these
real-fluid environments remains a main challenge. Different modeling approaches
have been employed, which can be categorized as diffused and sharp interface
methods. The objective of this study is to examine the diffused interface
method for simulating diesel-fuel injection at conditions related to the
supercritical regime. To this end, a recently developed compressible real-fluid
solver for transcritical conditions is employed. Simulations of an ECN-relevant
diesel-fuel injector are performed and predictions for instantaneous and
statistical flow-field results are compared against available measurements. It
is expected that results from this analysis will be useful in identifying
limitations of current modeling techniques and in improving physical and
numerical models for high-pressure injection systems.
