Combustion noise: Effects of the velocity turbulence of unburned mixture
Combustion noise: Effects of the velocity turbulence of unburned mixture
复制标题
燃烧噪声：未燃烧混合物的速度湍流的影响
DOI：
10.1016/0022-460x(90)90771-q
复制
发表时间：
1990
影响因子：
4.7
通讯作者：
K. Takamoto
中科院分区：
文献类型：
--
作者：
S. Kotake;K. Takamoto
通过插入丝网和延长燃烧器喷嘴长度，通过测量化学自由基光发射与声压之间的相关性，实验研究了未燃烧混合物的速度湍流对声学特性和燃烧噪声源强度分布的影响。随着湍流速度的增加，贫燃料火焰（φ < 1·6）的声功率增加，但富燃料火焰（φ > 1·6）变化不大。贫燃料火焰的声功率随湍流水平的增加归因于声压的高频分量的增加。自由基发射强度的时间导数与声压之间的相关性测量表明，对于贫燃料火焰，燃烧噪声源主要分布在燃烧区域的后部，对于富燃料火焰，燃烧噪声源主要分布在该区域的前部。随着湍流水平的提高，贫燃料火焰中的源强度在整个火焰区域上都会增加，而在富燃料火焰中，源强度仅转移到喷嘴出口，幅度变化很小。
By inserting wire screens and elongating the burner-nozzle length, effects of the velocity turbulence of the unburned mixture on the acoustic characteristics and the source strength distribution of combustion noise were studied experimentally by measuring the correlation between the optical emission of chemical radicals and the acoustic pressure. With increasing velocity turbulence, the acoustic power is increased for fuel-lean flames (φ < 1·6) but is little changed for fuel-rich flames (φ > 1·6). The increase in the acoustic power for fuel-lean flames with the turbulence level is attributed to the increase in higher-frequency components of the acoustic pressure. Measurement of the correlation between the time derivative of the radical emission intensity and the acoustic pressure indicates that the combustion noise source is distributed mainly in the rear part of the combustion region for fuel-lean flames and in the fore-part of this region for fuel-rich flames. With higher turbulence levels, the source strength in fuel-lean flames is increased over the whole region of the flame, and in fuel-rich flames it is only shifted to the nozzle exit, with little change in magnitude.