Local laminarization in turbulent diffusion flames
Local laminarization in turbulent diffusion flames
复制标题
湍流扩散火焰中的局部层化
DOI：
10.1016/0010-2180(80)90083-8
复制
发表时间：
1980
期刊：
影响因子：
--
通讯作者：
Akira Ishio
中科院分区：
文献类型：
--
作者：
T. Takagi;H. Shin;Akira Ishio
实验研究了有火焰和无火焰的圆形燃料射流中的湍流行为，注意到由于火焰的存在和不存在而导致的湍流特性的差异。通过对火焰的流速、湍流强度、气体温度和组分浓度的测量，定量验证了火焰的存在对湍流的抑制或层化作用。这一点在喷嘴出口附近的射流外层尤其明显，尽管射流的中心部分完全湍流;但相反，火焰的存在会促进下游的湍流。通过纹影摄影的直观研究清楚地表明，在较低的喷嘴流动雷诺数（如4，200）下，由于火焰的存在，在喷嘴出口附近的外层中存在明显的层化现象，即使在较高的雷诺数（如18，000）下，这种现象也顽固地存在。在无火焰射流中几乎没有观察到有火焰射流中的局部层流现象。
The behavior of turbulence in round fuel jets with and without flame is examined experimentally paying attention to the characteristic difference of turbulence due to the existence and nonexistence of flame. Measurements of flow velocity, turbulence intensity, gas temperature and species concentration are carried out and quantitative verification is presented for the facts that the existence of flame suppresses or laminarizes the turbulence. This is noted especially in the outer layer of the jet near the nozzle exit even though the central part of the jet is fully turbulent; but, on the contrary, the existence of flame promotes turbulence in the downstream. Visual study by schlieren photography shows clearly the local laminarization phenomena due to the existence of flame at lower nozzle flow Reynolds number (say, 4,200) and the apparent laminarization exists pertinaciously even at higher Reynolds number (say, 18,000) in the outer layer just near the nozzle exit. The local laminarization as in the jets with flame is scarcely observed in the jets without flame.