Transition from periodic to non-periodic motion of a bunsen-type premixed flame tip with burner rotation
Transition from periodic to non-periodic motion of a bunsen-type premixed flame tip with burner rotation
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随着燃烧器旋转，本生型预混火焰尖端从周期运动过渡到非周期运动
DOI：
10.1016/s1540-7489(02)80184-5
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
T. Ueda
中科院分区：
文献类型：
--
作者：
H. Gotoda;T. Ueda
本文从非线性动力学的观点对燃烧器旋转时本生型预混火焰的非定常运动进行了实验研究。来自燃烧管U的平均速度从0.6到1.2 m/s变化，并且燃烧管N的旋转速度从0到2800 rpm变化。使用当量比=1.43的富甲烷/空气混合物。当刘易斯数Le大于1时，在U=0.6m/s，旋流数S=1.14时，在非锥形火焰和平台火焰之间形成轴对称振荡火焰。这种变化的火焰尖端运动定性地表示通过绘制一个吸引子和定量评估通过估计的关联维数。当U≤0.8 m/s时，吸引子是一个极限环，关联维数Dcis估计约为1，表明吸引子是周期性运动。当U达到1.0 m/s时，吸引子的轨迹略微卷起，Dcap接近2，表明准周期火焰尖端运动。随着U的进一步增加，吸引子变得更加复杂，并且Dc被估计为非整数值，指示确定性混沌。这些结果表明，在Le>1的条件下，随着燃烧器的旋转，火焰尖端的运动从周期性变化到非周期性（即，混沌）。目前的研究结果还表明，基于确定性混沌理论的分析，如关联维数，是有效的量化的非定常火焰的运动。
Unsteady motions of a Bunsen-type premixed flame tip with burner rotation are experimentally investigatedfrom the viewpoint of nonlinear dynamics. The mean velocity from burner tube U is varied from 0.6 to 1.2 m/s, and the rotational speed of the burner tube N is varied from 0 to 2800 rpm. A rich methane/air mixture with the equivalence ratio of =1.43 is used. With the Lewis number Le larger than unity, an axisymmetric oscillating flame is formed between aconical flame and a plateau flame at U=0.6m/s and swirl number S=1.14, As U and N increase, but with S constant, the oscillating flame tip motion becomes unstable. This variation in the flame tip motion is shown qualitatively by drawing an attractor and evaluated quantitatively by estimating the correlation dimension. For U≤0.8 m/s, the attractor is a limit cycle and the correlation dimension Dcis estimated at about unity, indicating periodic motion. When U reaches 1.0 m/s, the trajectories of the attractor become rolled up slightly and Dcapproaches about 2, indicating quasi-periodic flame tip motion. With a further increase in U, the attractor becomes much more complicated and Dc, is estimated as a non-integer value, indicating a deterministic chaos. These results indicate that the flame tip motion with the burner rotation under the condition of Le>1 varies from periodic to non-periodic (i.e., to chaotic). The present results also show that an analysis based on deterministic chaos theory, such as the correlation dimension, is valid for quantifying the motion of unsteady flames.