Hydrazine (N2H4) and NTO (dinitrogen tetroxide: N2O4) mixtures are used in spacecraft bipropellant systems,having the advantage, for sampling missions, of having no carbon composition. However, no reasonable hydrazine and NTO combustion model has been developed. To construct a hydrazine and NTO combustion model that is useful for bipropellant thruster CFD simulation, we extracted efficient elementary reactions from detailed kinetic reaction model proposed by Ohminami and Ogawa in 2007. The reduced hydrazine and NTO combustion model was composed of 61 extracted reactions with 23 chemical species and was coincident with the original detailed kinetic reaction model in terms of combustion gas temperatures and ignition delay times over O / F (oxidizer and fuel mass ration) = 0.82-1.84. Also the simulated combustion gas temperatures were good agreed with the adiabatic flame temperatures, and the simulated ignition delay time at O / F = 1.2 was consistent with the literature value.
宇宙機の二液式推進薬として用いられるヒドラジンと四酸化二窒素について，気相の燃焼反応機構を縮小し新たな反応機構を構築した。大南と小川による30化学種245素反応式から構成される詳細反応モデルに対し，感度解析を用いて23化学種61素反応式まで反応規模の低減を行った。二液式スラスタの動作の範囲である酸化剤・燃料比（O / F）が0.82から1.84の間で，縮小された反応機構の解析値は，燃焼ガス温度と組成について詳細反応機構における解析値および断熱火炎温度と平衡計算による値によく一致する結果となった。また着火おくれ時間はO / F = 1.2で0.96 msecと文献値と合致する結果を得た。温度，組成，着火おくれに対して，縮小しても有用な反応モデルを構築できたことから，スラスタCFD解析への適用性を示したと考える。
Hydrazine, di-Nitrogen tetroxide, NTO, Reaction mechanism.