Nonlinear Dynamics of Premixed and Diffusion Flames

预混火焰和扩散火焰的非线性动力学

• 批准号: 0072588
• 负责人: Moshe Matalon
• 金额: $ 13.5万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-15 至 2003-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0072588&HistoricalAwards=false
• 关键词: Nonlinear; Dynamics; Premixed; Diffusion; Flames

0072588MatalonThe objective of the proposed work is to derive and analyze mathematical models that describe the dynamics of flames. The models will be derived systematically from the conservation laws of mass, momentum and energy by means of asymptotic methods and analyzed using analytical and numerical methods. It is proposed to identify mathematical models that contain enough details of the real combustion systems and analyze these models in order to gain basic understanding on how the physical and chemical processes interact in the simpler circumstances. Comparison with the experimental record will be performed in order to test the models and their predictions. The mathematical problems involve nonlinear evolution equations and nonlinear aspects of flame instabilities.The objective of the proposed work is to gain fundamental understanding in the complex processes occurring in combustion problems, problems that are encountered in various engineering applications. Improving our fundamental understanding of combustion phenomena could suggest new directions for applied research and lead to a better design of combustion systems. The problems that will be investigated are related to phenomena that have been observed in the laboratory but are not yet completely understood. The proposed work will address three classes of problems: The first class is concerned with the evolution of premixed flames in open space and in confined environments, where the coupled effects between the flame and the hydrodynamic field is of primary interest. Studies of premixed flames have significant technological importance and are directly applicable to internal combustion engines processes. The second class of problems is concerned with instabilities in non-premixed combustion, or diffusion flames, for which theoretical studies are only now emerging. Non-premixed conditions are favored in furnaces for safety reasons and in diesel engines here the liquid fuel evaporates in the combustion chamber providing the necessary fuel vapor that burns with air. The third class of problems is concerned with flame spread over flammable liquids, where the combined behaviors in the liquid and gas phases determine the flame dynamics. Flame spread over an accidental spillage of a flammable liquid, or a "running liquid fire" encountered in petrochemical industries, can become a fire hazard.

0072588Matalon提出的工作的目的是推导和分析描述火焰动力学的数学模型。这些模型将通过渐近方法从质量、动量和能量守恒定律系统地推导出来，并使用分析和数值方法进行分析。建议识别包含真实的燃烧系统的足够细节的数学模型，并分析这些模型，以获得关于物理和化学过程如何在较简单的情况下相互作用的基本理解。将与实验记录进行比较，以检验模型及其预测。数学问题涉及非线性发展方程和火焰不稳定性的非线性方面，所提出的工作的目标是获得在燃烧问题中发生的复杂过程的基本理解，在各种工程应用中遇到的问题。提高我们对燃烧现象的基本理解可以为应用研究提出新的方向，并导致更好的燃烧系统设计。将要研究的问题与在实验室中观察到但尚未完全理解的现象有关。拟议的工作将解决三类问题：第一类是关注的预混火焰在开放空间和密闭环境中，火焰和流体动力场之间的耦合效应的演变是主要的兴趣。预混火焰的研究具有重要的技术意义，并直接适用于内燃机过程。第二类问题涉及非预混燃烧或扩散火焰中的不稳定性，对此的理论研究现在才出现。出于安全原因，非预混条件在炉中是有利的，并且在柴油发动机中，液体燃料在燃烧室中蒸发，提供与空气一起燃烧的必要的燃料蒸气。第三类问题涉及可燃液体上的火焰传播，其中液相和气相的组合行为决定了火焰动力学。易燃液体的意外泄漏或石化工业中遇到的“流动液体火灾”上的火焰蔓延可能成为火灾危险。