How "flat" is the rich premixed flame produced by your McKenna burner?
How "flat" is the rich premixed flame produced by your McKenna burner?
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DOI：
10.1016/j.combustflame.2008.01.007
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发表时间：
2008-05-01
影响因子：
4.4
通讯作者：
Zizak, G.
中科院分区：
文献类型：
--
作者：
Migliorini, F.;De Iuliis, S.;Zizak, G.
麦肯纳燃烧器广泛应用于燃烧领域，用于产生“扁平”预混火焰。这些火焰被认为是光学技术开发和校准的标准。经常研究麦肯纳燃烧器产生的丰富预混火焰，以便通过光学和采样技术了解烟灰形成过程。测量通常沿着火焰轴进行，假设径向上温度和物质浓度分布均匀。这项工作表明，由带有不锈钢多孔塞的麦肯纳燃烧器产生的富预混合乙烯-空气火焰的烟灰径向分布可能远非“平坦”。烟灰主要分布在环形区域，非烟灰荧光物质存在于火焰核心。这一令人惊讶的结果在多种工作条件下得到了验证。此外，火焰不能被认为是轴对称的，而是呈现出倾斜的烟灰分布。另一个带有青铜多孔盘的麦肯纳燃烧器用于产生相同当量比和流量的火焰。这些火焰显示出完全不同的烟灰径向轮廓，更接近所声称的平坦分布。这些结果对使用不锈钢麦肯纳燃烧器进行的烟灰形成的几项研究得出的结论提出了质疑。 (c) 2008 年燃烧研究所。由爱思唯尔公司出版。保留所有权利。
McKenna burners are widely used in the combustion community for producing "flat" premixed flames. These flames are considered as standards for the development and calibration of optical techniques. Rich premixed flames produced by McKenna burners are frequently investigated in order to understand soot formation processes both by optical and by sampling techniques. Measurements are normally performed along the axis of the flames, with a uniform distribution of temperature and species concentration assumed in the radial direction. In this work it is shown that the soot radial profiles of rich premixed ethylene-air flames produced by a McKenna burner with a stainless steel porous plug may be far from being "flat." Soot is mainly distributed in an annular region and nonsoot fluorescing species are present in the core of the flames. This surprising result was verified under several working conditions. Furthermore, flames cannot be considered axial-symmetric but present a skewed soot distribution. Another McKenna burner with a bronze porous disk was used to produce flames of the same equivalence ratio and flows. These flames show a completely different soot radial profile, closer to the claimed flat distribution. These results cast doubts about the conclusions drawn in several studies on soot formation performed with a stainless steel McKenna burner. (c) 2008 The Combustion Institute. Published by Elsevier Inc. All rights reserved.