担当区分：筆頭著者,　責任著者   記述言語：英語   出版者・発行元：Elsevier BV  

Opposed two-stage ramps lower the total-pressure loss of a hydrogen oblique detonation combustor, but ethylene ignites more slowly, and whether the gain survives the weaker shocks of two stages, and how far the operating limit depends on the mechanism, is not known. A single 19° ramp and opposed 10° + 10° ramps in a 200 × 40 mm duct with stoichiometric ethylene–air are compared at flight Mach 9.5 to 11 in two-dimensional inviscid simulations with a 34-species San Diego subset and USC Mech II. With the subset both ramps are stationary at Mach 10 to 11 and the two-stage ramp recovers 1.56 to 1.60 times the total pressure of the single ramp, more than for hydrogen, consistent with burning downstream of the contraction. At Mach 9.5 the two-stage ramp recovers 0.153, whereas the single-ramp reaction zone travels upstream at 190 m/s as the subsonic region grows. With USC Mech II the two-stage ramp does not ignite at Mach 9.5 and consumes 27% of the fuel at Mach 10. A zero-dimensional sequential-shock model reproduces the reaction position on the single-ramp wall path and two-stage centre-plane path to within about 2 mm with the subset at Mach 10 to 11, but near the limit places it 30 to 45 mm upstream with either mechanism; the computed pressure history removes most of this deviation on the centre plane only. The gain carries over to ethylene, but its lower Mach limit is constrained by second-stage ignition and fuel consumption, which depend on the mechanism.

DOI： 10.2139/ssrn.7648545

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：（MISC）研究発表要旨（全国大会，その他学術会議）  

担当区分：筆頭著者   記述言語：日本語   掲載種別：（MISC）研究発表要旨（全国大会，その他学術会議）  

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japan Society for Aeronautical and Space Sciences  

DOI： 10.2322/tastj.22.aj19

担当区分：筆頭著者   記述言語：英語   掲載種別：（MISC）研究発表要旨（全国大会，その他学術会議）  

開催年月日： 2026年10月

記述言語：英語   会議種別：口頭（一般）  

開催年月日： 2026年4月

記述言語：日本語   会議種別：ポスター発表  

記述言語：日本語   会議種別：口頭（一般）  

記述言語：英語   会議種別：口頭（一般）  

記述言語：英語   会議種別：口頭（一般）