Analysis of Initial Flame Structure and Pressure Evolution in a Pre-Detonator under Varying Equivalence Ratios

Myeung Hwan Choi; Yuchang Gil; Sungwoo Park; Jungtae Cho; Taeha Kwon

doi:10.15231/jksc.2026.31.1.045

All Issue

2026 Vol.31, Issue 1 Preview Page

Research Article

Analysis of Initial Flame Structure and Pressure Evolution in a Pre-Detonator under Varying Equivalence Ratios 당량비에 따른 Pre-detonator 초기 화염 구조 및 압력 거동 특성 분석

31 March 2026. pp. 45-51

PDF XML

Abstract

This study experimentally investigates the ignition characteristics of a methane–air pre-detonator under varying equivalence ratios using ultra-high-speed visualization and dynamic pressure measurements. The ignition process was divided into initial ignition, secondary ignition induced by reflected shock waves, and exhaust stages. High-speed imaging showed that flame wrinkling increased with equivalence ratio, which is attributed to enhanced burning velocity, higher heat release rate, and intensified pressure rise under confined conditions. After passing through the DDT (deflagration-to-detonation transition) device, distinct Von-Neumann spikes were observed at downstream pressure sensors, indicating successful detonation transition. Although reflected shock waves induced secondary combustion within the chamber, their influence on transition behavior became limited once a sufficiently strong detonation wave was established. Quantitative analysis revealed that flame residence time decreased significantly with increasing equivalence ratio and approached a minimum threshold beyond unity. These results demonstrate that ignition behavior in a confined pre-detonator is governed by coupled effects of pressure rise, shock–flame interaction, and fuel–air ratio.

Keywords

Detonation

Pre-detonator

DDT

References

P. Wolański, Detonative propulsion, Proc. Combust. Inst. 34 (2013) 125–158.

10.1016/j.proci.2012.10.005

M.C. Kawalec, W. Perkowski, B. Łukasik, A. Bilar, P. Wolański, Applications of the continuously rotating detonation to combustion engines at the Łukasiewicz-Institute of Aviation, Combust. Engines, 61 (2022) 51-57.

10.19206/CE-145409

F.K. Lu, E.M. Braun, Rotating detonation wave propulsion: Experimental challenges, modeling, and engine concepts, J. Propul. Power, 30 (2014) 1125-1142.

10.2514/1.B34802

M.H. Choi, Y. Oh, S. Park, Investigation of spray characteristics for detonability: A study on liquid fuel injector and nozzle design, Aerospace, 11(6) (2024) 421.

10.3390/aerospace11060421

Y. Oh, M.H. Choi, S. Park, Experimental investigation of pulse detonation combustion characteristics via atomizer geometry, Aerospace, 11(9) (2024) 776.

10.3390/aerospace11090776

S.M. Frolov, V. Aksenov, V. Ivanov, I.O. Shamshin, S.A. Nabatnikov, Catapult launching tests of an unmanned aerial vehicle with a ramjet pulsed detonation engine, Proc. Eur. Conf. Aeronaut. Space Sci., (2018) 9-12.

R. Zhou, D. Wu, J. Wang, Progress of continuously rotating detonation engines, Chin. J. Aeronaut., 29 (2016) 15-29.

10.1016/j.cja.2015.12.006

Y.C. Gil, et al., Detonation wave combustion characteristic by fuel of pre-detonator, J. Korean Soc. Propul. Eng., 29(3) (2025) 37-44.

10.6108/KSPE.2025.29.3.037

Y. Gil, S. Lee, S. Han, S. Park, Impact of a variable blockage ratio on the detonation transition in a pre-detonator, Fire, 8(7) (2025) 263.

10.3390/fire8070263

Information

Publisher :The Korean Society of Combustion
Publisher(Ko) :한국연소학회
Journal Title :Journal of the Korean Society of Combustion
Journal Title(Ko) :한국연소학회지
Volume : 31
No :1
Pages :45-51
Received Date : 2026-03-04
Revised Date : 2026-03-13
Accepted Date : 2026-03-13
DOI :https://doi.org/10.15231/jksc.2026.31.1.045

Journal of the Korean Society of Combustion ISSN:1226-0959(Print) 2466-2089(Online) 한국연소학회지

All Issue