凹み壁面に衝突するメタン噴流における火花点火安定性に関するLES解析

抄録

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.