Flame dynamics under various backpressures in a model scramjet with and without a cavity flameholder

Nozomu Kato, Seong Kyun Im

Research output: Contribution to journalConference articlepeer-review

12 Citations (Scopus)


Flame dynamics under various backpressure conditions were experimentally investigated using direct flame visualization, high-speed CH∗chemiluminescence imaging, and wall pressure measurements. The stagnation pressure and temperature used in the present study were 100 kPa and 2500 K, respectively, with a freestream Mach number of 4.5. Rectangular scramjet models with and without a cavity were used to explore the effects of the cavity on flame dynamics when operating in scramjet mode, ramjet mode, and unstart. The flow rate of the ethylene jet was varied to impose backpressures corresponding to each operation mode. For both models, reverse flame propagation was observed for ramjet mode and unstart. For ramjet mode, flame fluctuation occurred within the isolator due to the coupling of fluid dynamics and combustion. The presence of a cavity enhanced combustion and reduced flame fluctuation in both scram and ramjet mode. The cavity promoted unstart because of the greater heat release from combustion. Further research using spatially resolved diagnostic techniques is needed to identify the flame locations for ramjet mode and unstart.

Original languageEnglish
Pages (from-to)3861-3868
Number of pages8
JournalProceedings of the Combustion Institute
Issue number3
Publication statusPublished - 2021
Event38th International Symposium on Combustion, 2021 - Adelaide, Australia
Duration: 2021 Jan 242021 Jan 29

Bibliographical note

Publisher Copyright:
© 2020 The Combustion Institute.


  • Cavity flameholder
  • Scramjet engine
  • Supersonic combustion

ASJC Scopus subject areas

  • General Chemical Engineering
  • Mechanical Engineering
  • Physical and Theoretical Chemistry


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