Formation of multiple flame fronts in heated micro channel

A phenomenon of simultaneous ignition of several fronts of chemical reaction in the micro channel with a walls temperature gradient was revealed. The gas combustion in straight tube and in the space between two disks with radial gas flow was theoretically investigated. In the both configurations the gas-gap clearance was less than critical diameter determined at ambient temperature and thus to sustain combustion the downstream walls temperature was over ambient temperature. Numerical simulations of flame repetitive ignition and extinction process revealed possibility of simultaneous ignition of two flame fronts at the hot part of the channel. One front was normal flame propagating upstream from hot to cold part of the channel whereas another front moved down stream and disappeared as the fuel burned down. On the base of the present study the new mechanism of ignition and incomplete combustion of a gas mixture in micro systems is offered.