The Influence of Moving Water Film on a Flame Propagation in Mixtures of H₂, and Air in a Tube

抄録

Flame propagation has been investigated experimentally in mixtures of H₂ and air in a tube with a moving water film on tube's walls. Significant differences in flame propagation with and without the moving water film are revealed. Significant intensification of combustion in these mixtures of hydrogen and air in the tube with a moving water film is demonstrated. For mixtures with relatively high burning velocities (hydrogen concentrations from 20 to 30 vol. %), the maximum explosion pressure with a moving water film is higher, than without one. Also, for mixtures with relatively low burning velocities (H₂ concentration 15 vol. %) the maximum explosion pressure with a moving water film is lower than without one. This effect is due to the competition between increased heat losses by water evaporation into the combustion products and lower heat losses because of combustion intensification. The multi-peak structure of the pressure-time curve during explosion of the gaseous mixture in the tube with a moving water film is revealed. A likely reason for this is the water film experiencing superheating at its intact with the hot combustion products until the temperature exceeds the limiting homogeneous nucleation temperature and explosive evaporation of the water film follows. The possibility of a shock wave in liquid adjacent to a cavity In the combustible mixture of hydrogen and air during its combustion is found. The maximum value of the pressure in a pressure wave in the liquid is 2 - 3 times higher than the maximum explosion pressure.