Effectiveness of plasma torches for ignition and flameholding in scramjet

Yukinori Sato, Masami Sayama, Katsura Ohwaki, Goro Masuya, Tomoyuki Komuro, Kenji Kudou, Atsuo Murakami, Kouichiro Tani, Yoshio Wakamatsu, Takeshi Kanda, Nobuo Chinzei, Itsuro Kimura

Research output: Contribution to journalArticlepeer-review

60 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)883-889
Number of pages7
JournalJournal of Propulsion and Power
Issue number4
Publication statusPublished - 1992 Jan 1
Externally publishedYes

ASJC Scopus subject areas

  • Aerospace Engineering
  • Fuel Technology
  • Mechanical Engineering
  • Space and Planetary Science


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