Special features of combustion of propane-air and hydrogen-air mixtures in a narrow tube

The special features of combustion-wave propagation in a narrow tube have been studied experimentally in low-velocity regimes for propane-air and hydrogen-air mixtures. For propane mixtures, the increase in the curvature of the flame surface correlates with the displacement of the maximum into the region of enriched mixtures in the dependence of the combustion velocity on the mixture composition. Combustion of lean hydrogen-air mixtures is accompanied by acoustic oscillations which lead to a narrowing of the range of flame, existence relative to the combustible-gas flow rate. For enriched mixtures, the flames are stable, and they exist at a hydrogen concentration close to the value for the upper concentration limit of flame propagation.