Abstract A solid fuel may be viewed as a special kind of gas of vanishing molecular mobility. Accordingly, a forward smolder wave may be regarded as a special kind of diffusion flame with fuel Lewis number tending to infinity. Such a perspective is explored in this study to examine the structural characteristics of steady planar forward smolder waves, with particular emphasis placed on the heat loss effects. The problem is formulated by employing a diffusive-thermal model, in which the complex smolder reactions are modeled by a one-step exothermic char oxidation reaction. For both adiabatic and non-adiabatic cases, the reaction layer is analyzed by using the activation energy asymptotic method, which ends up with jump conditions connecting quantities across the reaction front. The asymptotic results indicate that adiabatic forward smolder waves do not have a blowoff limit in the small Damkohler number limit, whereas a quenching limit develops when heat loss effects are incorporated. For non-adiabatic forward smolder waves with a reaction trailing structure, the leakage of oxygen through the reaction layer vanishes to leading order, so the reaction zone is described by a structure that is essentially analogous to the premixed flame regime of diffusion flames. By contrast, in the presence of heat loss the reaction leading structure is characterized by O(1) leakage of both reactants, so the analogy is with the partial burning regime of diffusion flames. The description of these two distinct structures, however, can be unified through a common dimensionless parameter m, which is defined as the fraction of heat conducted to the fresh solid fuel side among the total amount of heat generated in the reaction zone.

中文翻译：

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前向阴燃波的扩散火焰模拟：（I）一维稳定结构

摘要 固体燃料可以看作是一种分子运动性消失的特殊气体。因此，前向阴燃波可以看作是燃料路易斯数趋于无穷大的一种特殊的扩散火焰。本研究探讨了这种观点，以检查稳定平面前向阴燃波的结构特征，特别强调热损失效应。该问题是通过采用扩散热模型来表述的，其中复杂的阴燃反应通过一步放热炭氧化反应建模。对于绝热和非绝热情况，反应层通过使用活化能渐近方法进行分析，最终以跳跃条件连接反应前沿的数量。渐近结果表明绝热前向阴燃波在小 Damkohler 数限制中没有吹散限制，而在结合热损失效应时会出现淬火限制。对于具有反应拖尾结构的非绝热前向阴燃波，通过反应层的氧气泄漏消失到先导顺序，因此反应区由基本上类似于扩散火焰的预混火焰状态的结构来描述。相比之下，在存在热量损失的情况下，反应主导结构的特点是两种反应物的 O(1) 泄漏，因此类比与扩散火焰的部分燃烧制度。然而，这两种不同结构的描述可以通过一个共同的无量纲参数 m 来统一，