MMH/NTO双组元自燃推进剂反应机理简化

采用反应流分析结合灵敏度分析的简化方法,对MMH/NTO详细燃烧化学反应机理进行了简化,获得包含25个组分和43个基元反应的MMH/NTO简化反应动力学模型。并从着火延迟时间和燃烧火焰温度两方面,通过对比理论结果、详细机理和简化机理预测结果,在较宽范围参数内对简化机理进行了验证。验证结果表明简化机理和详细机理预测的MMH/NTO体系的着火延迟时间和燃烧火焰温度具有非常高的一致性,说明了简化反应机理的合理性。进而分析了初始温度、燃烧室压力、氧燃比对MMH/NTO体系的着火延迟时间和燃烧火焰温度的影响规律,MMH/NTO体系的着火特性对初温和燃烧室压力较为敏感,燃烧火焰温度则对氧燃比和燃烧室压力较为敏感。为后续发动机燃烧的CFD数值计算提供了准确的反应动力学模型。

Investigation of reduced chemical kinetic model of MMH/NTO hypergolic propellants

In this paper,reacting flow analysis combined with sensitivity analysis was used to simplify the detailed chemical mechanism of MMH/NTO hypergolic propellants developed in our previous research.And the reduced kinetic model consisting of 25 species and 43 elementary reactions was obtained.From ignition delay time and combustion flame temperature,the reduced model has been validated against the theoretical results and detailed model at wider conditions.The validation shows that the ignition delay times and combustion flame temperatures predicted by the reduced model are highly consistent with that of the detailed model.Furthermore,the influence of initial temperature,chamber pressure and oxygen/fuel mass ratio on the ignition delay time and combustion flame temperature was analyzed.The results show that the ignition characteristics of MMH/NTO bipropellant systems are more sensitive to initial temperature and chamber pressure,while the combustion characteristics are more sensitive to O/F and chamber pressure.The present research provides are duced and accurate kinetic model for multi-dimensional CFD(Computational Fluid Dynamics)combustion simulation in engine combustor.