Flame-Vortex Interaction in Laminar Gaseous and Spray Diffusion Flames

GOMEZCTS-9904296是层流逆流气体和喷雾扩散火焰与层流涡相互作用的实验和计算研究。应用了几种激光诊断技术，包括测量气体和液滴速度以及液滴尺寸分布的双组分相位多普勒干涉法；测量气相温度的斯托克斯/反斯托克斯拉曼散射；测量主要组分浓度和确定混合物分数的线拉曼散射；以及监测火焰对涡激扰动的响应的平面激光诱导的甲醛(CH2O)、羟基(OH)和甲烷(CH)的荧光。在可行的情况下，这些技术被锁相以等待漩涡的到来。在计算上，气相使用欧拉公式建模，液滴相使用拉格朗日公式建模；该模型包括详细的传输和化学动力学以及尺寸分布的影响。重点是甲醇和庚烷火焰，燃料以喷雾或蒸汽形式提供。该方法旨在提供对火焰-涡旋相互作用的理解，包括时间依赖性和曲率对火焰结构、消光和重燃行为以及污染物形成的影响。

ABSTRACTALESSANDRO GOMEZCTS-9904296This is an experimental and computational investigation of the interaction of laminar counterflow gaseous and spray diffusion flames with laminar vortices. Several laser diagnostic techniques are applied, including two-component phase Doppler interferometriy to measure gas and droplet velocities and the droplet size distribution; Stokes/antiStokes Raman scattering to obtain gas-phase temperature; line Raman scattering to measure the concentrations of major species and to determine the mixture fractions; and planar laser-induced fluorescence of formaldehyde (CH2O), hydroxyl (OH), and methyne (CH) to monitor flame response to the vortex-induced perturbation. When feasible, these techniques are phase-locked to the arrival of the vortex. Computationally, the gas phase is modeled using an Eulerian formulation and the droplet phase is modeled using a Lagrangian formulation; the model includes detailed transport and chemical kinetics and size distribution effects. The emphasis is on methanol and heptane flames with the fuel supplied either as a spray or in vapor form. The approach is intended to provide an understanding of the flame-vortex interaction, including the effects of time dependence and curvature on flame structure , extinction and re-ignition behavior, and pollutant formation.