Mathematical Sciences: Instabilities in Premixed and Diffused Flames

小行星9403890 本程序涉及预混和扩散（非预混）火焰的动态行为。建议推导出简化的数学模型，允许在开放和封闭的环境中的一般形状的火焰的描述，并研究在此框架内的火焰行为的动力学方面的渐近和微扰方法辅以数值计算。将解决的具体问题包括识别与扩散火焰相关的固有不稳定性，探索复杂的非均匀流场和由于限制的影响，并检查火焰蔓延的液体燃料的动力学的预混火焰的动态和稳定性。 建议的研究的意义是提高目前的理解复杂的现象，在燃烧过程中所涉及的。这项工作不仅对燃烧科学具有重要意义，而且对实际应用也有直接的意义。 该提案包括一个基础研究计划，其目的是获得对复杂的化学和物理过程如何在真实的燃烧系统中相互作用的基本理解。所考虑的问题包括在各种工程系统中感兴趣的开放和封闭环境中的预混可燃气体的燃烧，在意外溢出的火灾危险中非常重要的易燃液体上的火焰传播，以及与消防安全和防火最相关的纯（非预混）燃料的燃烧。为了深入了解这些问题，特别是负责维持燃烧和负责燃烧的机制，建议开发简化的数学模型并深入分析它们。这种识别因果关系的方法很可能解释和指导实验观察。深刻的理解往往会为实验和设计提供新的方向。

9403890 Matalon This program is concerned with the dynamic behavior of premixed and diffusion (non-premixed) flames. It is proposed to derive simplified mathematical models that permit the description of flames of general shapes in open and confined environments, and to study dynamical aspects of flame behavior within this framework by means of asymptotic and perturbation methods supplemented by numerical computations. Specific problems that will be addressed include identifying intrinsic instabilities associated with diffusion flames, exploring the dynamics and stability of premixed flames complicated by non uniform flow fields and by effects due to confinement, and examining the dynamics of flame spread over liquid fuels. The significance of the proposed research is enhancement of the current understanding of the complex phenomena involved in combustion processes. The proposed work is not only of fundamental importance to combustion science but has also direct relevance to practical applications. This proposal consists of a basic research program whose aim is gaining fundamental understanding on how the complex chemical and physical processes interact in real combustion systems. The problems under consideration include the burning of premixed combustible gases in open and confined environments which is of interest in various engineering systems, flame spread over flammable liquids which is of great importance in fire hazards with accidental spillage, and the burning of pure (nonpremixed) fuels which is most relevant to fire safety and fire prevention. To gain insight into these problems, and in particular into the mechanisms responsible for the sustenance of the burning and those responsible for its extinguishement, it is proposed to develop simplified mathematical models and analyze them in depth. This approach, which identifies cause and effect, is likely to explain and guide experimental observations. A deep understanding often lead to suggest ions of new directions for experiments and design.