Increasing engine efficiency is essential to reducing emissions, which is a
priority for automakers. Unconventional modes such as boosted and highly dilute
operation have the potential to increase engine efficiency but suffer from
stability concerns and cyclic variability. To aid engineers in designing
ignition systems that reduce cyclic variability in such engine operation modes,
reliable and accurate spark-ignition models are necessary. In this article, a
Lagrangian–Eulerian spark-ignition (LESI) model is used to simulate electrical
discharge, spark channel elongation, and ignition in inert or reacting crossflow
within a combustion vessel, at different pressures, flow speeds, and dilution
rates. First the model formulation is briefly revisited. Then, the experimental
and simulations setups are presented. The results showcase the model’s ability
to predict the secondary circuit voltage, current, and power signals, in
addition to the spark channel elongation, for the inert cases, or flame front
growth, for the reacting cases. The results also compare simulation spark
channel and flame growth plots to experimental Schlieren images at different
instants in time. This work serves to highlight LESI’s ability to predict the
characteristics of discharge and ignition across a variety of operating
conditions.
