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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

湍流可以提高预混混合气的燃烧速度，也可以熄灭火焰。湍流对内燃机湍流燃烧过程的影响依赖于湍流混合与化学反应的复杂相互作用。因此，为了弄清局部火焰熄灭与细小火焰结构的关系，有必要研究湍流混合和化学反应对它们的影响。本研究从实验和理论两个方面进行了研究。实验研究中，采用纹影摄影和激光薄片层析成像技术对火焰的细微结构进行可视化，利用被动静电探头探测火焰区的细小火焰。通过实验工作，直观地显示了小火焰曲率及其在独立控制燃烧过程中的变化，火焰区的小火焰数从1到6，随着Turn-…比例的增加而增加层流燃烧速度越大，气泡强度越大。火焰面纹影照片和被动静电探针法揭示的多火焰片事实支持了火焰带的岛状特征，但激光薄片层析成像尚未观察到，可能是由于层析图像的对比度不足所致。在理论研究中，建立了从层流到湍流火焰的预混燃烧模型，并为火焰结构和湍流燃烧速度提供了参数。为了弄清火焰结构与湍流燃烧速度之间的关系，迄今用于火焰结构相图的三个坐标系(Re-Da，eta_K/eta_0-u‘/S_&lt；L0&gt；L/eta_0-u’/S_&lt；L0&gt；)相互关联，并用图表的形式表示模型预测的燃烧速度和火焰结构参数。较少