LES Analysis on the Spark Ignitability of an Impinging Methane Jet on Cavity Wall

Abstract

Flow and mixture formation of a methane jet with impingement on a cavity wall were calculated using a large eddy simulation (LES). The calculations were performed for varying wall shapes and the nozzle-to-wall distance. In addition, the spark ignitability is discussed based on the distributions of flow and fuel concentration. The result shows that flow and shear stress are suppressed and fuel concentration increases in the cavity and the flammable mixture is widely distributed. Furthermore, a distribution of the turbulent Karlovitz number Ka is estimated based on the velocity and equivalence ratio. When the mixture is spark-ignited at the point of Ka<50, a stable combustion is achieved.