Quantitative Measurements and Modeling in Partially-Premixed Cellular Tubular Flames

1606005 -Pitz为了设计高效和清洁的燃烧室，需要简化的化学动力学和分子输运模型，以准确和有效地预测用于加热，陆地和空气推进的燃烧。蜂窝管状火焰模拟实际火焰，是预测和实验验证简化燃烧模型的有效平台。 火焰细胞排列成圆柱对称的几何形状，可以在台式计算机上进行数学简化和预测。在实验室中，可以用先进的激光方法快速测量对称的火焰单元图案，以评估使用简化的燃烧模型的预测。经过验证的简化化学动力学和分子输运模型可用于计算机代码，以准确预测实际汽车发动机、家用炉和飞机喷气发动机的燃烧和污染物排放。这项研究的成功将导致更清洁和更有效的燃烧在美国，以帮助经济和环境。该项目将研究细胞管状火焰与定量测量和建模，以评估简化模型的分子传输和化学动力学。 详细的二维（2D）模拟将验证与激光成像和测量的主要物种浓度的拉曼散射和径向物种（OH，H，O）的激光诱导荧光（LIF）在细胞火焰是预混，非预混和部分预混。H和O原子浓度是用飞秒（fs）激光测量的，以避免激光光解的干扰。利用经验证的计算有效的2D管状火焰模型，简化了分子传输模型（例如，混合物平均传输和近似Soret效应模型）和减少种类的化学动力学机制，可以开发用于燃烧氢气、甲烷和丙烷的更精确的湍流燃烧模型。一旦详细的二维模型得到验证，简化的传输和化学动力学机制将被开发和/或评估用于湍流燃烧建模。通过对蜂窝结构的多标量测量验证的定量2D模型将为开发用于加热、能源生产和推进的实际燃烧室的氢和烃火焰的简化模型提供数据。飞秒激光对H和O原子定量测量的发展将导致世界上其他研究小组采用fs-LIF方法。研究生和本科生将参与研究，重点是招募代表性不足的少数民族。学生将在研究会议上展示他们的成果。学生将与空军研究实验室/光谱能量在代顿，俄亥俄州飞秒激光测量合作，让他们广泛接触最新的计算机模拟和激光诊断设施。

1606005 - PitzTo design efficient and clean combustors, simplified chemical kinetic and molecular transport models are needed for accurate and efficient prediction of combustion used for heating, land and air propulsion. Cellular tubular flames mimic practical flames and are an efficient platform to predict and experimentally validate simplified combustion models. The flame cells are arrayed in a cylindrically symmetric geometry that can be mathematically simplified and predicted on a desktop computer. The symmetrical flame cell pattern can be measured quickly in the laboratory with advanced laser methods to assess predictions using the simplified combustion models. Validated simplified chemical kinetic and molecular transport models can then be used in computer codes to accurately predict combustion and pollution emission in practical car engines, house furnaces and aircraft jet engines. Success of this research will lead to cleaner and more efficient combustion in the U.S. to help the economy and the environment.The project will study cellular tubular flames with quantitative measurements and modeling in order to evaluate simplified models of molecular transport and chemical kinetics. The detailed two-dimensional (2D) simulation will be validated with laser imaging and measurements of major species concentration by Raman scattering and radial species (OH, H, O) by laser-induced fluorescence (LIF) in cellular flames that are premixed, non-premixed and partially premixed. The H and O atom concentrations are measured with a femtosecond (fs) laser to avoid interference from laser photolysis that plagued earlier efforts. With the validated computationally efficient 2D tubular flame models, simplified models of molecular transport (e.g., mixture-averaged transport and approximate Soret effect models) and reduced species chemical kinetic mechanisms can be developed for more accurate turbulent combustion models burning hydrogen, methane and propane. Once the detailed 2D model is validated, simplified transport and chemical kinetic mechanisms will be developed and/or evaluated for use in turbulent combustion modeling. Quantitative 2D models verified by multi-scalar measurements of cellular structures will provide data for development of simplified models of hydrogen and hydrocarbon flames used for practical combustors in heating, energy production and propulsion. Development of H and O atom quantitative measurements with femtosecond lasers will lead to adoption of the fs-LIF method by other research groups in the world. Graduate students and undergraduate students will be involved in research with an emphasis in recruiting underrepresented minorities. Students will present their results at research conferences. Students will collaborate with the Air Force Research Laboratory/Spectral Energies in Dayton, Ohio on femto-second laser measurement giving them a broad exposure to the latest computer simulation and laser diagnostic facilities.