Dynamics and stability of premixed hydrogen-air flames in square microchannels with wall temperature gradients

摘要: Abstract The dynamics and stability of premixed hydrogen-air flames in square microchannels with heated walls were investigated through three-dimensional direct numerical simulations. inlet velocity equivalence ratio 1.5 m/s 0.5. effect the wall temperature gradient characteristics on flame was examined varying width location for a channel height 1.5 mm. Five distinct modes observed at different profiles: repetitive extinction-ignition (FREI), pulsating flame, laterally oscillating spinning steady modes. Furthermore, transitions between these specific inflow boundary conditions. by from 1.0 mm to 1.677 mm fixed gradient. As increased, four modes, namely, FREI, appeared sequentially. To determine whether this sequential appearance associated variation heat loss, maximum changed small amounts. For lower temperature, mode transitioned FREI mode, higher unstable such as disappeared, resulting stable flame.