Mathematical Modeling of Combustion Phenomena at the Microscale

微尺度燃烧现象的数学模型

• 批准号: 0708588
• 负责人: Moshe Matalon
• 金额: $ 14.63万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-15 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0708588&HistoricalAwards=false
• 关键词: Mathematical; Modeling; Combustion; Phenomena; Microscale

Matalon0708588 The objective of the project is to enhance physicalunderstanding of the intricate processes occurring in combustionat the microscale, in order to support and guide ongoingexperimental efforts in this area. Mathematically, the problemsrequire finding solutions to coupled, highly nonlinear partialdifferential equations, further complicated by inevitabletemporal variations, multi-scale processes, and nontrivialboundaries. Tractable problems require judicious modelingefforts in order to capture the main features of the phenomenaunder consideration. The simplified models are addressed usingappropriate analytical or numerical strategies in order toprovide solutions that enable comparing the theoreticalpredictions with experimental observations. The investigatorexamines two sets of problems. The first set is associated withpremixed combustion in an excess-enthalpy combustor where the hotcombustion products are recirculated to heat up the freshreactants, thus enhancing the burning rate and heat output. Thesecond set of problems is associated with nonpremixed combustionin a confined slot, where the mixing zone and the resultingdiffusion flame spread over the entire length of the reactorchannel. The goal is to study the structure, properties anddynamics of flames in such configurations and identify conditionsfor steady burning, onset of instabilities, flashback or blowoff,and flame extinguishment. Combustion is a subject of great economical and societalconcern. Despite the continuing search for alternative energysources, combustion still provides the majority of the energyconsumed today. It is therefore important to ensure thatcombustion processes are utilized in the most efficient way, andin such a way as to minimize undesirable effects on theenvironment. Recent development in the field of microscalecombustion has been motivated by the increased need for smallerscale and high density power sources and by the fact thathydrocarbon fuels have enormous advantages over batteries interms of energy storage per unit mass. There are, however,important issues that need to be addressed in order to renderthis technology practical and efficient. Beyond the difficultiesassociated with fabrication, fundamental questions concerned withthe underlying combustion physics need to be overcome. Thedevelopment of combustion systems at the microscale requiresdeeper understanding at the fundamental level of fluid flow inmicrochannels, heat and mass transport at the small scale,combustion in small volumes and complex geometries, thermal andchemical properties of the wall materials, and fluid-wallinteractions. Mathematical modeling plays an important roletowards this goal; it provides means to explain experimentalobservations and identify the physical mechanisms responsible forthese observations. The investigator, building on his earliercontributions to fluid mechanics and chemically reacting flows,studies the peculiarities of combustion at the microscale inorder to improve physical understanding of these phenomena. Byguiding and supporting the ongoing experimental efforts theproject has an immediate effect on advancements of this newtechnology.

MATALON0708588该项目的目的是增强对微观燃烧中发生的复杂过程的物理知识，以支持和指导该领域正在进行的经验性努力。 从数学上讲，问题的问题找到解决方案以耦合，高度非线性的partiandifferendendifferendections方程，这使得异常变化，多尺度过程和非散热器的解决方案更加复杂。 可处理的问题需要明智的建模效果，以捕获现象考虑的主要特征。 使用适当的分析或数值策略来解决简化的模型，以便将理论预测与实验观察结果进行比较。 调查甲胺两组问题。 第一组与过量的植物燃烧器中的燃烧相关，在该燃烧器中，将热量产物再循环以加热新鲜反应剂，从而提高了燃烧速率和热量输出。 第三个问题与非构造燃烧素有关的狭窄插槽有关，其中混合区域和所得延伸火焰分布在反应渠道的整个长度上。 目的是研究此类配置中火焰的结构，特性和dymanics，并确定稳定燃烧，不稳定性的发作，回落或打击以及火焰灭绝的条件。 燃烧是一个伟大的经济和社会界面的主题。 尽管持续寻找替代的能源，但燃烧仍然提供了当今大部分的能源。 因此，重要的是要以最有效的方式确保使用该过程，并以最小化对环境的不良影响的方式。 微观燃烧领域的最新发展是出于对小规模和高密度功率来源的需求的增加，以及氢碳燃料在每单位质量的能量存储中具有巨大的优势。 但是，为了使这项技术实用有效，需要解决重要的问题。 除了与制造相关的困难之外，还需要克服与基本燃烧物理学有关的基本问题。 燃烧系统在显微镜上的开发需要在流体流动通道的基本水平上进行干燥的理解，小规模的热和质量传输，小体积和复杂的几何形状，壁的热和化学性质，壁材料的热和化学性质，以及流体 - 瓦尔瓦尔瓦尔瓦尔瓦尔（Floid Wallictractions）。 数学建模扮演着重要的roletowards。它提供了解释实验性守护并确定负责人的物理机制的手段。 研究者基于他对流体力学和化学反应流的早期贡献，研究了微观阶段燃烧的特殊性，以提高对这些现象的物理理解。 逃避和支持正在进行的实验努力对项目的进步有直接的影响。