A new ignition model for spark-ignited engine simulations (Q5940979)

The amount of spark energy deposited into the combustion chamber is key to an optimum ignition as one can end up with misfires when this energy is low or with other undesired effects on engine performance and byproducts when it is high. Experimentally, up to now, no one has been able to correlate the combustion outcome accurately to the spark parameters in a controllable way. Theoretical investigation and computer modeling is leading to a better understanding of how spark flames propagate. A new computational approach to ignition dynamics is presented here for spark-ignited engine combustion simulations. Our computational model, using the MPI communication library, attempts to solve temporal and spatial equations of the electromagnetic equations in conjunction with the well-known Navier-Stokes equations of the standard KIVA-3 engine code. The interaction between the gas and the flame (plasma) kernel in the spark region is computed through the momentum and energy exchange between these two fields. Preliminary results show a distinct spatial distribution of physical quantities at the flame front and within the inflammation zone. A slight change in the spark discharge current has significant impact on the combustion and emissions. Enhanced accuracy of spark ignition modeling might help us better compute the early flame propagation and its influence on the cyclic variability of engines, potentially leading to design of new spark plugs.