Effectiveness of plasma torches for ignition and flameholding in scramjet
Effectiveness of plasma torches for ignition and flameholding in scramjet
复制标题
等离子炬在超燃冲压发动机中点火和火焰稳定的有效性
DOI：
10.2514/3.23565
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
I. Kimura
中科院分区：
文献类型：
--
作者：
Yukinori Sato;Masami Sayama;Katsura Ohwaki;G. Masuya;T. Komuro;Kenji Kudou;Atsuo Murakami;K. Tani;Y. Wakamatsu;T. Kanda;N. Chinzei;I. Kimura
为了研究一种新型的以空气或氧气为原料的等离子炬在超燃冲压发动机燃烧室中的点火和保焰效果，对其进行了实验研究。这种设计是从超燃冲压发动机和飞行器整体系统设计的角度出发的，因为采用进气或机载推进剂作为进料是比较理想的。测试了三种喷油模式：1)从一个孔喷射；2)从一个壁面上的四个孔喷射；3)两边墙上的九个孔。通过燃烧室内部和出口火焰的直接照片和壁面温度测量来检查点火和保持火焰的现象。这种特殊设计的等离子炬在没有任何辅助气体（例如氩气）的情况下也能稳定地工作。在空气总温度与燃料当量比的平面上，对三种喷油方式进行了点火极限曲线的比较。在广泛的实验条件下，结果表明，空气或氧气等离子体炬的效率与氮或氩氢等离子体炬相当。对于单壁喷射，观察到等离子炬点燃了位于正下游的燃料射流，由此形成的火焰点燃了相邻的燃料射流。然而，在双壁喷射中，从等离子炬对面的壁上喷射的燃料点火不成功。还发现，在某些条件下，即使在等离子炬关闭后，火焰仍然可以继续保持，特别是在单壁注射的情况下。这种现象的发生或不发生也显示在点火极限曲线图中。
A newly developed plasma torch with a feed stock of air or oxygen was investigated experimentally in order to determine its effectiveness on ignition and flameholding in a scramjet combustor. This design comes from the viewpoint of total system design of scramjet engine and vehicle because it is preferable to utilize incoming air or onboard propellants as a feed stock. Three patterns of fuel injection were tested 1) from one orifice: 2) from four orifices on one wall; and 3) from all nine orifices on both walls. Ignition and flameholding phenomena were examined through direct photographs of internal and exit flames of the combustor and by wall temperature measurements. The specially devised plasma torch with air or oxygen was able to operate stably without any support gas, for example, argon. Ignition limit curves, with and without the plasma torch, were obtained on a plane relating the air total temperature to the fuel equivalence ratio for the three patterns of fuel injection, and then compared to each other. For a wide range of experimental conditions, it was shown that the effectiveness of an air or oxygen plasma torch was comparable to that of a nitrogen or argon-hydrogen plasma torch. For single-wall injection, it was observed that the plasma torch ignited the fuel jet located directly downstream, and the flame thus formed ignited adjacent fuel jets. In double-wall injection, however, ignition of the fuel injected from the wall opposite the plasma torch was unsuccessful. It was also found that, under some conditions, flameholding can be continued even after the plasma torch is turned off, most notably in the case of single-wall injection. The occurrence or nonoccurrence of this phenomenon is also shown in the ignition limit curves diagram.