Cellular combustion at the transition of a spherical flame front to a flat front at the initiated ignition of methane–air, methane–oxygen and n-pentane–air mixtures

High-speed cinematography was used to study the transition of a spherical flame front to a flat front in n-pentane–air and methane–air mixtures initiated by a spark discharge. Cellular flame structures were observed at the transition. Modeling based on compressible reactive Navier–Stokes equations at a low Mach number showed a qualitative agreement with experimental data.