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传输模型，以准确和高效地预测用于加热、陆地和空气推进的燃烧。蜂窝状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。火焰单元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。利用先进的激光方法，可以在实验室中快速测量对称的火焰单元图案，以评估使用简化燃烧模型进行的预测。经过验证的简化化学动力学和分子传输模型随后可以用于计算机代码，以准确预测实际汽车发动机、家庭炉子和飞机喷气发动机的燃烧和污染排放。这项研究的成功将在美国带来更清洁和更高效的燃烧，以帮助经济和环境。该项目将通过定量测量和建模来研究蜂窝状管状火焰，以评估分子传输和化学动力学的简化模型。详细的二维(2D)模拟将通过激光成像和通过拉曼散射测量主要组分浓度以及通过激光诱导荧光(LIF)测量预混、非预混和部分预混蜂窝火焰中的径向物种(OH，H，O)浓度来验证。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，而激光光解曾困扰着早期的努力。利用经过验证的计算高效的2D管状火焰模型，可以建立简化的分子传输模型(例如，混合物平均传输和近似Soret效应模型)和简化的物种化学动力学机理，以便建立更准确的燃烧氢、甲烷和丙烷的湍流燃烧模型。一旦详细的2D模型被验证，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模拟。通过对蜂窝结构的多标量测量验证的定量2D模型将为开发用于实际燃烧室的加热、能量产生和推进的氢和碳氢火焰的简化模型提供数据。利用飞秒激光进行氢原子和氧原子定量测量的发展将导致世界上其他研究小组采用飞秒激光诱导荧光方法。研究生和本科生将参与研究，重点是招收代表性不足的少数族裔。学生们将在研究会议上展示他们的成果。学生们将与俄亥俄州代顿市的空军研究实验室/光谱能源公司合作进行飞秒激光测量，使他们能够广泛接触到最新的计算机模拟和激光诊断设备。

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.