Abstract Although there has been a lot of work on ignition times at constant imposed heat flux and on steady creeping flame spread, no definite results exist for the effect of material thickness on these phenomena, specifically away from purely thermally thick or thermally thin conditions. In this work, we first demonstrate, concentrating on the thermal ignition regime, that creeping flame spread can be cast in the form of ignition time at constant heat flux if surface heat losses are neglected. Subsequently, we review relations for ignition time for thermally thick, intermediate and thermally thin conditions including the effects of critical heat flux and heat losses. Finally based on these analyses we present for the first time, new nondimensional correlations and a theoretical way to include the effects of material thickness on creeping flame spread in a practical way as derived from exact equations in the ignition analysis. Then, we compare and validate the new relations using an earlier semi-empirical correlation developed by the author based on numerical and experimental data as well as with recent data.

中文翻译：

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材料厚度对热状态下点火时间和蠕动火焰蔓延的影响：理论、解析解和实验证明

摘要 尽管在恒定外加热通量下的点火时间和稳定的蠕动火焰蔓延方面已经有很多工作，但材料厚度对这些现象的影响没有明确的结果，特别是在远离纯热厚或热薄条件的情况下。在这项工作中，我们首先证明，专注于热点火机制，如果忽略表面热损失，则可以在恒定热通量下以点火时间的形式投射蠕动火焰蔓延。随后，我们回顾了热厚、中间和热薄条件下点火时间的关系，包括临界热通量和热损失的影响。最后基于我们首次提出的这些分析，新的无量纲相关性和理论方法，以实际方式包括材料厚度对蠕动火焰蔓延的影响，这是从点火分析中的精确方程得出的。然后，我们使用作者根据数值和实验数据以及最近的数据开发的早期半经验相关性来比较和验证新关系。