NTO/UDMH燃烧机理构建与着火特性分析  

Construction of NTO/UDMH combustion mechanism and analysis of ignition characteristics

作　　者：杨丹奇 卓丹晨 吴润生 金平[1,3] 蔡国飙 YANG Danqi;ZHUO Danchen;WU Runsheng;JIN Ping;CAI Guobiao(School of Astronautics,Beihang University,Beijing 102206,China;China Manned Space Agency,Beijing 100094,China;National Key Laboratory of Aerospace Liquid Propulsion,Beijing 102206,China)

机构地区：[1]北京航空航天大学宇航学院,北京102206 [2]中国载人航天工程办公室,北京100094 [3]航天液体动力全国重点实验室,北京102206

出　　处：《火箭推进》2024年第5期82-95,共14页Journal of Rocket Propulsion

基　　金：国家重点项目;载人航天工程科技创新团队课题。

摘　　要：为提高自燃推进剂液体火箭发动机燃烧流场的CFD数值计算精度,基于分级法思想构建了63组分357基元反应的四氧化二氮(NTO)/偏二甲肼(UDMH)详细燃烧机理。分别采用单一简化方法与综合多种简化方法对详细机理进行简化,得到与详细机理吻合较好的35组分149基元反应和23组分19基元反应。在此基础上,研究了不同压力、温度与氧燃比对详细机理与简化机理着火特性的影响规律:增大初始压力整体会增加系统平衡温度与着火延迟时间,初始压力越大,系统平衡温度增加越慢,从1035~1320 K/MPa减小至170~320 K/MPa;初始温度的升高会增加系统平衡温度但缩短了着火延迟时间,初始温度增加1 K,系统平衡温度约增大3 K;增大氧燃比会降低系统平衡温度、增大着火延迟时间,氧燃比越大,着火延迟时间增加越多。获得的规律为NTO/UDMH反应动力学研究提供了重要的参考依据与理论基础,构建得到的详细及简化机理有助于建立更加准确的发动机燃烧流场仿真模型。To improve the CFD numerical calculation accuracy of the combustion of hypergolic propellant liquid rocket engines,a detailed combustion mechanism of nitrogen tetroxide(NTO)/unsymmetrical dimethylhydrazine(UDMH)with 63 components 357 elementary reactions was constructed based on the hierarchical method.The detailed mechanism was simplified using a single simplification method and a combination of multiple simplification methods,resulting in 35 components 149 elementary reactions and 23 components 19 elementary reactions that were in good agreement with the detailed mechanism.Based on this,the influence of different pressures,temperatures,and the ratios of oxygen and fuel on the ignition characteristics of the detailed mechanism and simplified mechanism was studied.Increasing the initial pressure will integrally increase equilibrium temperature and ignition delay time of the system.And the higher initial pressure leads to the slower the system equilibrium temperature increment:decreasing from 1035-1320 K/MPa to 170-320 K/MPa.Meanwhile,the increase in initial temperature will increase the equilibrium temperature of the system but shorten the ignition delay time.When the initial temperature increases by 1 K,the equilibrium temperature of the system will increase by about 3 K.The growth of the oxygen fuel ratio will lower the system equilibrium temperature and raise the ignition delay time.Larger oxygen fuel ratio results in a rapid increase in ignition delay time.The law provides an important reference and theoretical basis for the study of NTO/UDMH reaction kinetics.The detailed and simplified mechanism constructed helps to establish a more accurate simulation model of engine combustion flow field.

关 键 词：偏二甲肼 四氧化二氮 反应机理构建 机理简化 

分 类 号：V511.4[航空宇航科学与技术—航空宇航推进理论与工程]