EFFECTS OF VITIATED AIR ON HYDROGEN IGNITION IN A HIGH-SPEED LAMINAR MIXING LAYER
EFFECTS OF VITIATED AIR ON HYDROGEN IGNITION IN A HIGH-SPEED LAMINAR MIXING LAYER
复制标题
高速层流混合层中污染空气对氢气点火的影响
DOI：
10.1080/00102200490256018
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发表时间：
2004
影响因子：
1.9
通讯作者：
M. Nishioka
中科院分区：
文献类型：
--
作者：
B. Han;Chih;M. Nishioka
在实验室超音速燃烧研究中使用污浊空气来模拟飞行焓的一个相关的复杂性是测试介质被不代表实际大气的物种污染。当燃烧富氧空气中的氢被用来产生污浊空气在实验中，产生的高焓气流包含大量的，例如，H2O，H，OH，O，和NO。因此，本数值研究的主要目的是评估污浊空气的影响在超音速实验中的点火特性。具体而言，在高速氢气/空气层流混合层的点火演变计算模拟使用详细的化学和传输特性。单个和组合的重要污染物对点火的影响进行了系统的检查，在一个范围内的压力，空气温度，和自由落体速度的变化。活性自由基，如H，O和OH的Vitiations，发现增强点火，如预期的。H2O和NO污染分别对超声速点火有抑制和促进作用。计算结果上的净效应的同时污染的H，O，OH，H2O，和NO的点火响应进一步提供洞察的实验数据的解释，使用污浊的空气设施。
One associated complication for the use of vitiated air in laboratory supersonic combustion studies to simulate flight enthalpy is that the test media are contaminated by species that are not representative of the actual atmosphere. When burning hydrogen in oxygen-enriched air is employed to produce vitiated air in experimentation, the resulting high-enthalpy airflow contains substantial amounts of, for example, H2O, H, OH, O, and NO. Therefore, the primary objective of the present numerical study is to assess the effects of vitiated air on the ignition characteristics in supersonic experiments. Specifically, the ignition evolution in the high-speed hydrogen/air laminar mixing layer is computationally simulated using detailed chemistry and transport properties. Individual and combined influences of important contaminants on ignition are systematically examined over a range of pressure, air temperature, and freestream velocity variations. Vitiations of the active radicals, like H, O, and OH, are found to enhance ignition, as expected. Results also show that contamination of H2O and NO can inhibit and promote supersonic ignition, respectively. The computed results on the net effect of simultaneous contaminations of H, O, OH, H2O, and NO on the ignition response further provide insight into the interpretation of the experimental data using the vitiated air facilities.