多孔介质内稀氢气/空气预混过滤燃烧不稳定性

Filtration combustion instability with lean premixed hydrogen/air in porous media

在不同过滤速度和氢气体积分数试验参数下观测超绝热燃烧波传播过程中火焰面倾斜不稳定性演变过程及热斑组成的胞状结构燃烧波的特点,分析导致过滤燃烧不稳定性发生的动力学因素,确认低速过滤燃烧不稳定性的演变机理及其特点.结果表明:在火焰面有一个初始轻微的倾斜角时,这种倾斜不稳定性演变持续性发展;改变试验工况参数,在燃烧器上游可能会出现胞状结构体燃烧波;在主燃烧波传播过程中,胞状结构燃烧波显著影响着主燃烧波火焰面传播的稳定性并且抑制主波的传播速度;当主燃烧波离开燃烧器后,胞状结构燃烧波随机分布驻定在燃烧器内部.

The evolution of flame front inclination instability and the property of cellular structure com- bustion waves with hot spots were determined during the superadiabatic combustion wave propagation for different filtration velocity and hydrogen concentration. The dynamic factor leading to the filtration com- bustion wave instability was analyzed. The evolution mechanism and the characteristics for low-velocity filtration combustion instability were verified. The results show that the flame front inclinational instability develops continuously when the flame has an initial tiny inclinational angle. When the experimental con- dition parameters are changed, the cellular structure combustion waves may emerge at the upstream side of the combustor. The cellular structure combustion waves have strong effect on the stability of the main combustion wave propagation, and can depress the main wave propagation velocity. When the main combustion wave leaves combustor, the cellular structure combustion waves distribute randomly and stand in combustor.