Surface heat loss and chemical kinetic response in deflagration to detonation transition in microchannels

The effects of cold, hot, and adiabatic walls on flame propagation and deflagration-to-detonation transition (DDT) in a microscale channel are investigated by high-resolution numerical simulation. Results show that the conducting, cold, and hot walls lower the flame acceleration rate, while DDT can occur and originate from local explosion near the flame tip for both the hot and adiabatic walls. Furthermore, for the adiabatic wall, autoignition near the wall produces fast flames in the boundary layer, inducing two shocks propagating and colliding at the center, inducing a local explosion near the flame tip. However, for the hot wall, fast flames do not appear in the boundary layer due to heat loss at the wall; DDT occurs due to coupling of the compression waves with the stretched flame, and needs strong local explosion due to the absence of autoignition in the boundary layer. Nevertheless, compared with the adiabatic …