Dynamics of Radiative Low-Stretch Diffusion Flames

辐射低拉伸扩散火焰的动力学

• 批准号: 0119073
• 负责人: Chih-Jen Sung
• 金额: $ 24.8万
• 依托单位: Case Western Reserve University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0119073&HistoricalAwards=false
• 关键词: Dynamics; Radiative; Low; Stretch; Diffusion

This is an experimental and theoretical investigation of the structure and extinction behavior of gaseous diffusion flames at low stretch rates. The low-stretch condition is created by bottom-burning of a fuel mixture discharged from a porous axisymmetric burner of very large radius. Fuels studied include methane, hydrogen, carbon monoxide/hydrogen, and carbon monoxide/methane. Spatially resolved species, temperature, and velocity profiles are measured with laser diagnostics. Flame radiation and burner-surface radiation are also examined. Corresponding theoretical models are developed incorporating a narrowband radiation model. The study consists of five elements: (1) experimental determination of the flammability limit boundaries as functions of stretch rate and the amount of fuel dilution with emphasis on the radiation- induced extinction; (2) experimental exploration for the existence of "flamelets"; (3) experimental mapping of flame structure including hydrodynamic, thermal, and species profiles and radiation intensities from the flame and burner surface; (4) detailed modeling of low-stretch diffusion with detailed chemistry, transport properties, and flame/surface radiation; and (5) development of detailed radiation models including flame-surface interaction in a spectral manner and reevaluation of mean band parameters.

本文对气体扩散火焰在低拉伸速率下的结构和消光行为进行了实验和理论研究。低拉伸条件是由大半径多孔轴对称燃烧器排出的混合燃料底燃产生的。研究的燃料包括甲烷、氢、一氧化碳/氢和一氧化碳/甲烷。空间分辨物种，温度，和速度分布测量激光诊断。火焰辐射和燃烧器表面辐射也进行了检测。结合窄带辐射模型，建立了相应的理论模型。研究包括五个方面的内容：(1)实验确定可燃性极限边界作为拉伸率和燃料稀释量的函数，重点研究辐射致灭；(2)对“小火苗”存在的实验探索；(3)火焰结构的实验测绘，包括流体力学、热学和物质剖面以及火焰和燃烧器表面的辐射强度；(4)低拉伸扩散的详细建模，包括详细的化学、输运性质和火焰/表面辐射；(5)建立了包括火焰-表面光谱相互作用在内的详细辐射模型，并重新评估了平均波段参数。