This document discusses the hydrogen combustion flame with a special focus on the flame velocity profile in relationship to combustion pressure and temperature. First, the chemistry associated with hydrogen combustion is discussed along with the important factors that affect the hydrogen flame. Then some of the models for hydrogen flame velocity are discussed. Computational analysis is performed to determine the trend of the flame velocity profile in relation to pressure and temperature above and below the adiabatic temperature point. Twelve test cases, made of combinations of pressure and temperature variations, are used to monitor the trend of the velocity profile when the temperature was under the adiabatic temperature point and when it was above the adiabatic temperature point. It is shown that increasing pressure or temperature, or both, always increased the flame velocity, which is consistent with the physics law. However, this study demonstrated that below the hydrogen adiabatic point, the hydrogen flame average velocity was much more responsive; it increased more than 9 times than when the temperature was above the adiabatic point; it only increased about 5 times. This was observed over the same range of applied pressure and the same range of applied temperature. A physics-based explanation is presented for this trend by considering the kinetic energies associated with the hydrogen species above and below the adiabatic point and the completeness of the combustion. It is also found that the peak velocity profile took place at around 40% of hydrogen concentration.

本文件讨论了氢气燃烧火焰，特别关注与燃烧压力和温度相关的火焰速度分布。首先，讨论与氢燃烧相关的化学以及影响氢火焰的重要因素。然后讨论了氢火焰速度的一些模型。执行计算分析以确定火焰速度分布与绝热温度点之上和之下的压力和温度相关的趋势。十二个测试案例，由压力和温度变化的组合组成，用于监测温度低于绝热温度点和高于绝热温度点时的速度分布趋势。结果表明，增加压力或温度，或两者兼而有之，总是增加火焰速度，这符合物理定律。然而，这项研究表明，在氢绝热点以下，氢火焰平均速度的响应要快得多；温度高于绝热点时增加9倍以上；它只增加了大约 5 倍。这是在相同的施加压力范围和相同的施加温度范围内观察到的。通过考虑与绝热点上方和下方的氢物种相关的动能以及燃烧的完整性，对这一趋势提出了基于物理学的解释。还发现峰值速度分布发生在氢浓度的 40% 左右。该研究表明，在氢绝热点以下，氢火焰平均速度的响应要快得多；温度高于绝热点时增加9倍以上；它只增加了大约 5 倍。这是在相同的施加压力范围和相同的施加温度范围内观察到的。通过考虑与绝热点上方和下方的氢物种相关的动能以及燃烧的完整性，对这一趋势提出了基于物理学的解释。还发现峰值速度分布发生在氢浓度的 40% 左右。该研究表明，在氢绝热点以下，氢火焰平均速度的响应要快得多；温度高于绝热点时增加9倍以上；它只增加了大约 5 倍。这是在相同的施加压力范围和相同的施加温度范围内观察到的。通过考虑与绝热点上方和下方的氢物种相关的动能以及燃烧的完整性，对这一趋势提出了基于物理学的解释。还发现峰值速度分布发生在氢浓度的 40% 左右。它只增加了大约 5 倍。这是在相同的施加压力范围和相同的施加温度范围内观察到的。通过考虑与绝热点上方和下方的氢物种相关的动能以及燃烧的完整性，对这一趋势提出了基于物理学的解释。还发现峰值速度分布发生在氢浓度的 40% 左右。它只增加了大约 5 倍。这是在相同的施加压力范围和相同的施加温度范围内观察到的。通过考虑与绝热点上方和下方的氢物种相关的动能以及燃烧的完整性，对这一趋势提出了基于物理学的解释。还发现峰值速度分布发生在氢浓度的 40% 左右。