Modeling Reacting Interfaces for Biomass Combustion using Flame Generated Manifolds

这个项目将回答当固体或液体燃烧时会发生什么的基本问题。任何材料的燃烧都涉及燃料表面附近复杂的传热传质过程。这些反应界面通常存在于化学能转化为热能的工程问题中。例子包括生物质加热，固体火箭发动机和内燃机。然而，描述这些界面的数学模型仍然是预测燃烧性能的主要挑战之一。这项研究的重点是发展新的数学理论和进行基于激光的测量，以了解反应界面的性质。这一努力对社会的影响是提供科学的见解，在燃料转化为有用的能源，用于发电和供暖。开发精确的模型来描述反应界面仍然是燃烧科学的艰巨任务。根本的困难是耦合的热量和质量传输与化学反应的长度和时间尺度远远小于系统规模的利益。使这些挑战复杂化的是液体或固体燃料表面的响应，其在燃烧过程中回归并且取决于局部火焰结构。为了减少问题的自由度，火焰产生的反应界面的流形将在本研究中进行探索。新建模方法的吸引力在于，它将重要的质量和热传输过程与化学动力学的详细描述相结合，从而可以准确预测能量转换率和有害污染物。所提出的方法将被用来预测向上的火焰蔓延的合成和天然材料。为了验证模型的预测，直接数值模拟和实验计划。实验将采用可调谐二极管激光吸收光谱探测反应燃料表面附近的物质组成和温度。该研究的预期短期影响是为燃烧和火灾建模社区提供小火焰生成的歧管库。这项研究的长期影响是提供一个高保真，基础广泛的计算工具和实验技术，以了解和预测生物质材料的燃烧。

This project will answer the fundamental question of what happens when solids or liquids burn. The burning of any material involves complex heat and mass transfer processes near the fuel surface. These reacting interfaces are commonly found in engineering problems where chemical energy is converted to thermal energy. Examples include biomass heating, solid rocket motors, and internal combustion engines. Mathematical models to describe these interfaces, however, continue to be one of the main challenges in predicting combustion performance. This study focuses on developing new mathematical theories and conducting laser-based measurements to understand the nature of reacting interfaces. The impact of this effort to society is to offer scientific insight in the conversion of fuels to useful energy for power production and heating.Developing accurate models to describe reacting interfaces remain a daunting task in combustion science. The fundamental difficulty is the coupling of thermal and mass transport with chemical reactions at length and time scales that are far smaller than system scales of interest. Compounding these challenges is the response of liquid or solid fuel surfaces, which regress during the burning process and are dependent on local flame structure. To reduce the degree of freedom of the problem, flamelet generated manifolds of the reacting interfaces will be explored in this research. The appeal of the new modeling approach is that it couples important mass and thermal transport processes with detailed descriptions of chemical kinetics, thus allowing for accurate predictions of energy conversion rates and harmful pollutants. The proposed method will be used to predict upward flame spread over both synthetic and natural materials. To validate model predictions, both direct numerical simulation and experiments are planned. The experiments will employ tunable diode laser absorption spectroscopy to probe species composition and temperature near at the reacting fuel surface. The expected short-term impact of the research is to provide a flamelet generated manifold library to the combustion and fire modeling community. The long-term impact of this research is to provide a high-fidelity, broad-based computational tool and experimental techniques to understand and predict the burning of biomass materials.