An Experimental Approach to Vortex-Flame Interaction in Practical Turbulent Fields

实际湍流场中涡旋火焰相互作用的实验方法

基本信息

批准号：
12650201
负责人：
OHIWA Norio
金额：
$ 2.3万
依托单位：
Nagoya Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650201/
关键词：
Turbulent Premixed Flame Turbulent Burning Velocity Vortex-Flame Interaction Plane Shear Flow Coherent Structure Karman Vortex Street Wake behind Cylindrical Rod Array Unsteady Propagating Flame 乱流予混合火炎円柱格子乱流火炎と渦の相互干渉火炎伸長トモグラフィ

项目摘要

In this investigation the processes of vortex-flame interaction of a spark-ignited flame with either coherent structure in the plane premixed shear flow or Karman vortex street in the wake behind a fine cylindrical rod array are experimentally examined, in order to clarify effects of adjacent eddies on the vortex bursting. Propane-air mixture is used in this investigation with an equivalence ratio varied. The results obtained are summarized as follows.(1) In case of the spark ignition at the center of a large scale organized eddy, a flame propagates faster in the axial direction than in the radial one, indicating that the vortex motion enhances the propagation velocity. After completing combustion within an eddy, a pair of flames protrude to adjacent boundary regions on upstream and downstream sides and propagate in the flow direction. The propagation velocity is promoted by the rolling-up motion inherent in the shear flow. In case of the spark ignition at the boundary between adjacent eddies, a flame extends along the contact surface between two mixture streams and becomes S-shaped. It is found that the flame velocity in the flow direction is almost equal to that in the axial direction. When the tips of S-shaped flame reach adjacent eddies, the vortex bursting again enhances the axial flame propagation. It is concluded that there exist two kinds of vortex-flame interactions; one is the vortex bursting, the other is the vortex boosting, and that combination of these two enhancement mechanisms constitutes one of the key factors to the turbulent combustion.(2) A spark-ignited young flame generated in the mixture wake behind a fine cylindrical rod array suffers from the intense cooling and stretching by multiple attacks of Karman vortex. The vortex-flame interaction, therefore, can not always augment flame propagation, but lead to flame extinction in the weak mixture.

在这项调查中，经过实验检查，在平面预混合的剪切流中与平面预混合剪切流或Karman Vortex街中的涡旋 - 弗拉米相互作用的过程在实验中进行了细胞圆柱杆阵列后面的尾巴，以阐明相邻涡流对涡旋爆发的影响。丙烷 - 空气混合物用于此研究，等效比各种。所获得的结果总结如下。（1）如果在大规模组织的涡流中心的火花点火中，火焰在轴向方向上的传播速度要比径向的传播更快，这表明涡流运动增强了传播速度。在涡流内完成燃烧后，一对火焰向上和下游侧面的相邻边界区域突出，并在流动方向上传播。剪切流中固有的滚动运动促进了传播速度。如果在相邻涡流之间的边界处发生火花点火，则火焰沿两个混合物流之间的接触表面延伸并变为S形。发现在流动方向上的火焰速度几乎等于轴向方向的速度。当S形火焰的尖端到达相邻的涡流时，涡流爆发再次增强了轴向火焰传播。得出的结论是，存在两种涡旋式相互作用。一个是涡旋破裂，另一个是涡旋的提升，这两种增强机制的组合构成了动荡的燃烧的关键因素之一。（2）在混合物中产生的火花燃烧的年轻火焰产生的一个关键因素之一，唤醒了精美的圆柱形杆阵列，受到了kertysense scooting and take take take of kentry the the oftsents vortsex的高级圆柱形杆阵列。因此，涡旋形式的相互作用不能总是增强火焰传播，而是导致弱混合物中的火焰灭绝。