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Relationship between the Fine Flame Structure and the Local Flame Quenching Mechanism in the High Intensity Turbulent Propagating Flame

高强度湍流传播火焰中精细火焰结构与局部火焰淬灭机制的关系

基本信息

批准号：
02650159
负责人：
KIDO Hiroyuki
金额：
$ 1.22万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

项目摘要

Turbulence can increase the burning velocity of premixed mixture, it can extinguish the flame, either. The effects of turbulence on the turbulent combustion process in internal combustion engines depend on the complicated interaction of the turbulent mixing with the chemical reaction therein. Therefore, to clarify the relation of the local flame quenching with the fine flame structure, it is necessary to investigate how they are affected by the turbulent mixing and chemical reaction. This has been done experimentally and theoretically in this study.In the experimental study, the schlieren photography and laser-sheet tomography were used to visualize the fine structure of the flame, and passive electrostatic probes to detect the flamelets from the flame zone. By the experimental work, the curvature of the flamelets and its variation with independently controlled combustion was visualized and the flamelet number in the flame zone measured from 1 to 6, increasing with the ratio of the tur … More bulence intensity to the laminar burning velocity. The islandlike feature of the flamelets in the zone was suggested by schlieren photographs of the flame and supported by the multi-flamelet fact revealed by the passive electrostatric probe method, but has not yet observed by the laser-sheet tomography probably owing to the deficient contrast of the tomograms. The conditions for flame quenching have also been determined experimentally for several mixtures with relatively low laminar burning velocities.In the theoretical study, such a model has been developed which describes the premixed combustion from laminar to turbulent flames, and provides parameters for the flame structure as well as the turbulent burning velocity. In order to clarify the relationship between the flame structure and turbulent burning velocity, three coordinate systems (Re-Da, eta_K/eta_0-u'/S_<L0>, L/eta_0-u'/S_<L0>) SO far used for the flame structure phase-dia, , rams individually, were shown to be related to one another and used to present the model-predicted burning velocities and flame structure parameters in the form of diagrams. Less

湍流可以增加预混料的燃烧速度，也可以熄灭火焰。紊流对内燃机湍流燃烧过程的影响取决于其中的湍流混合与化学反应的复杂相互作用。因此，为了弄清局部火焰淬火与精细火焰结构的关系，有必要研究它们如何受到湍流混合和化学反应的影响。本研究已在实验和理论上做到了这一点。在实验研究中，采用纹影摄影和激光层析成像技术可视化火焰的精细结构，并采用被动静电探针检测火焰区域的小火焰。通过实验工作，可视化了独立控制燃烧时小火焰的曲率及其变化，火焰区的小火焰数在1 ~ 6之间，随着旋转强度与层流燃烧速度的比值增加而增加。火焰的纹影照片和被动静电探针法揭示的多火焰事实支持了该区域内小火焰的岛状特征，但由于层析成像的对比度不足，尚未通过激光层析成像观察到。实验还确定了几种具有较低层流燃烧速度的混合物的火焰淬火条件。在理论研究中，建立了描述层流火焰到湍流火焰的预混合燃烧模型，并提供了火焰结构参数和湍流燃烧速度参数。为了澄清火焰结构和湍流燃烧速度之间的关系,三坐标系统(Re-Da eta_K / eta_0-u”/ S_ L0 < >, L / eta_0-u / S_ L0 < >)到目前为止用于火焰结构phase-dia,公羊,被证明是彼此相关的,并用于呈现模型预测燃烧速度和火焰的形式结构参数图。少