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拟议工作的目标是得出描述火焰动力学的数学模型。这些模型将通过渐近方法系统地从质量，动量和能量的保护定律中得出，并使用分析和数值方法进行分析。建议确定包含真实燃烧系统细节的足够细节的数学模型，并分析这些模型，以便在简单的情况下对物理和化学过程如何相互作用获得基本的了解。将与实验记录进行比较，以测试模型及其预测。数学问题涉及非线性进化方程和火焰不稳定性的非线性方面。拟议工作的目的是在燃烧问题中发生的复杂过程中获得基本的理解，这些问题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提出应用研究的新方向，并导致更好的燃烧系统设计。将要研究的问题与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：第一类与开放空间和狭窄环境中预混合火的演变有关，在火焰和流体动力场之间的耦合效应引起了主要兴趣。预混合火焰的研究具有重要的技术重要性，并且直接适用于内燃机工艺。第二类问题涉及非燃烧或扩散火焰中的不稳定性，而理论研究仅出现了。出于安全原因，在炉子和柴油发动机中，液体燃料在燃烧室中蒸发，从而在燃烧室中受到青睐。第三类问题与火焰散布在易燃液体上有关，在易燃液体上，液体和气相中的联合行为决定了火焰动力学。火焰散布在易燃液体的意外溢出或石化工业中遇到的“运行液体火”中可能会成为火灾危害。