Numerical study on non-uniform detonation initiation in H2/O2/N2 mixture

In this study, two-dimensional numerical simulations considering detailed chemistry and transport are conducted to investigate the non-uniform detonation initiation. The high-pressure and high-temperature detonation initial regime is imposed by a sinusoidal disturbance. It is shown that the disturbance promotes the onset of detonation. For disturbance with smaller wave length, the distance of detonation initiation becomes shorter due to stronger shock wave interaction. Moreover, the influence of wall boundary layer on detonation initiation is examined. At the boundary layer, the kinetic energy transforms into the thermal energy. Hence, autoignition happens near the wall, which is accompanied by pressure wave generation. The pressure wave collision induces local high temperature and local explosion, which eventually results in detonation. Therefore, both disturbance and wall boundary layer promote detonation initiation.