权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Dynamical motion of Bunsen flame tip with flow rotation

本生火焰尖端随流动旋转的动态运动

基本信息

批准号：
14550195
负责人：
UEDA Toshihisa
金额：
$ 2.37万
依托单位：
Keio University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14550195/
关键词：
Premixed flame rotating flow chaos Lewis number effect Buoyancy force ブンゼン火炎層流火炎回転 LIF 振動火炎非周期火炎

项目摘要

The dynamic motion of Bunsen flame tip with flow rotation has been investigated experimentally. The premixed mixture (methane/air mixture or propane/air mixture) is injected upwards from a tube burner with inner diameter 12 mm. The burner is rotated with arbitrary rotation speed. Since the honeycomb is installed in the burner, the flow rotation obtained can be assumed as a rigid body rotation. When the burner is not rotated (the Swirl number S=0), well known conical Bunsen flame is formed. When the Lewis number of the premixed mixture is more than unity, the cone shape flame shifts to the oscillating flame at around S=1.04 with increasing S. With further increase in S, the flame shifts to the plateau flame. The frequency of the flame tip motion decreases with increasing S. This is due to a decrease in the axial velocity with increasing the effect of centrifugal force by a flow rotation. The amplitude of the flame tip motion of the conical flame and plateau flame is as small as that of the conical flame without flame rotation, while that of the oscillating flame increases by a factor of five compared to the conical flame without flow rotation. This significant increase in the amplitude of the flame tip oscillation is due to the combined effect of the buoyancy force and the variation in flame intensity under the influence of the Lewis number. When the injection velocity from the burner and the rotating speed of the burner are increased, keeping S=1.04, the oscillating flame shifts to a quesi-oscillating flame. The quesi-oscillating flame shifts to a complex oscillating flame with further increase in the injection velocity and the burner rotating speed. The complex oscillating flame shows chaotic characteristics. These results elucidated that the time series chaotic analysis is useful to quantify characteristics of complex flame motion.

实验研究了本生灯火焰尖在流动旋转条件下的动态运动。预混混合物（甲烷/空气混合物或丙烷/空气混合物）从内径12mm的管式燃烧器向上喷射。燃烧器以任意转速旋转。由于蜂窝安装在燃烧器内，得到的流动旋转可以假设为刚体旋转。当燃烧器不旋转时（旋流数S=0），形成众所周知的锥形本生灯火焰。当预混料的Lewis数大于1时，随着S的增加，圆锥形火焰在S=1.04附近向振荡火焰转移，随着S的进一步增加，火焰向平台火焰转移。火焰尖端运动的频率随着s的增加而降低，这是由于流动旋转离心力的作用增加，轴向速度降低。锥形火焰和平台火焰的火焰尖端运动幅度与没有火焰旋转的锥形火焰相同，而振荡火焰的火焰尖端运动幅度比没有流动旋转的锥形火焰增加了5倍。火焰尖端振荡幅度的显著增加是由于浮力和刘易斯数影响下火焰强度变化的共同作用。当燃烧器喷射速度增大，燃烧器转速保持S=1.04时，振荡火焰转变为准振荡火焰。随着喷射速度和燃烧器转速的进一步增大，准振荡火焰转变为复杂振荡火焰。复杂振荡火焰表现出混沌特性。这些结果表明，时间序列混沌分析是量化复杂火焰运动特性的有效方法。