Similarity and difference of flame-flow interactions in an open tube and in a closed chamber

Flame propagation through a combination of vortices in an open tube and in a closed chamberresembling a clearance of an SI-engine is investigated using direct numerical simulations of a setof the combustion and hydrodynamic equations. For burning in tubes, we demonstrate how theburning rate depends on the root-mean-square (rms) flow velocity, the vortex size, the thermalexpansion in burning and other flame-flow parameters. The dependence on the vortex intensity(rms-velocity) is almost linear in agreement with the general belief. The dependence on the vortexsize may be imitated by a 2/3 power law. Two cases (of a single-mode vortex array and of a multimodecombination of vortices obeying the Kolmogorov spectrum) are considered. In the case ofburning in a closed chamber, various initial flow conditions in the chamber are studied includinggas at rest and initial sets of vortices of different size / rms-velocities. It is shown that flame-flowinteraction leads to a strong flame corrugation, with noticeable increase in the burning rate. Unlikefor burning in an open tube, there is an optimal vortex size in a closed chamber, which providesthe fastest total burning rate / shortest time of burning.