Abstract

The experimental research results on diffusion combustion of a round hydrogen microjet flowing from a slit micronozzle at subsonic and supersonic speeds are presented. For the first time, four scenarios of diffusion combustion of a round hydrogen microjet have been identified, including supersonic combustion in the presence of supersonic cells both in air and in hydrogen. It has been found that flame stabilization for a subsonic microjet velocity of hydrogen is associated with the presence of a “bottleneck flame region” leading to the nozzle choking phenomenon, and flame stabilization for a supersonic microjet flow is associated with the presence of supersonic cells. A hysteresis of the diffusion combustion process of a plane microjet of hydrogen is found depending on the method of ignition of the microjet (near or far from the nozzle exit) and the direction of change in the rate of its outflow (growth or decrease).

中文翻译：

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圆形氢微射流在亚音速和超音速喷射速度下的扩散燃烧

摘要

给出了从狭缝微喷嘴以亚音速和超音速移动的圆形氢微射流扩散燃烧的实验研究结果。首次确定了圆形氢微射流的扩散燃烧的四种情况，包括在空气和氢气中都有超音速电池的情况下的超音速燃烧。已经发现，氢的亚音速微喷射速度的火焰稳定与导致喷嘴阻塞现象的“瓶颈火焰区域”的存在相关，而超音速微喷射流的火焰稳定与超音速电池的存在相关。