Turbulence/Premixed-Flame Interactions in Isotropic Turbulence

各向同性湍流中的湍流/预混火焰相互作用

• 批准号: 9019813
• 负责人: Gerard Faeth
• 金额: $ 14.86万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-02-01 至 1994-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9019813&HistoricalAwards=false
• 关键词: Turbulence; Premixed; Flame; Interactions; Isotropic

The influence of preferential diffusion of reactant species on the propagation of a flame through a turbulent gaseous fuel/oxidizer mixture is to be studied by a series of experiments in a constant volume, fan-stirred combustion chamber. The velocity field and turbulence quantities will be measured using two-point laser velocimetry and particle-image velocimetry, and laser flame tomography will be used to determine the instantaneous flame surface. Hydrogen/oxygen/nitrogen mixtures producing preferential diffusion with a stabilizing influence on the flame structure will be chosen to cover a wide range of laminar flame speeds, and the turbulence intensity and integral scale of the reactants will be controlled independently. The test range will involve the thin laminar flamelet regime for turbulent Reynolds numbers up to 10,000. The flame propagation process will be simulated theoretically using statistical time-series techniques as a way to interpret the measurements, and as a way to initiate the development of a computationally tractable predictive tool which includes a rational treatment of the flow physics. Understanding the interaction between turbulence and the speed with which a flame propagates into a combustible mixture is a fundamental issue in combustion science. The results of this research will provide insight into one aspect of this complex phenomena, with applications possible to internal combustion engines and turbulent premixed combustion processes in general.

在定容的风扇搅拌燃烧室中，通过一系列实验研究了反应物的优先扩散对火焰在湍流的气体燃料/氧化剂混合物中传播的影响。使用两点激光测速仪和粒子图像测速仪测量速度场和湍流量，并使用激光火焰层析成像技术确定瞬时火焰表面。将选择对火焰结构具有稳定影响的优先扩散的氢/氧/氮混合物来覆盖大范围的层流火焰速度，并且将独立地控制反应物的湍流强度和积分尺度。试验范围将涉及雷诺数高达10,000的薄层流火焰区。火焰传播过程将使用统计时间序列技术进行理论模拟，作为解释测量结果的一种方式，并作为一种开始开发一种计算上易于处理的预测工具的方式，其中包括对流动物理的合理处理。了解湍流与火焰传播到可燃混合物中的速度之间的相互作用是燃烧科学中的一个基本问题。这项研究的结果将提供对这一复杂现象的一个方面的洞察，并可能应用于内燃机和湍流预混燃烧过程。