【作者】 肖锋；

【导师】 沈赤兵；

【作者基本信息】 国防科学技术大学 ， 航空宇航科学与技术， 2005， 硕士

【摘要】 本文研究的过氧化氢自燃点火器,采用分段式结构,燃料喷入过氧化氢的高温分解产物中,蒸发并自燃。介绍了有关自燃的燃烧动力学理论、Semenov自燃理论以及应用Semenov方程对自燃范围进行预测的方法。介绍了过氧化氢的催化分解过程、催化分解方式、催化评估以及一维情况下的催化分解模型。对过氧化氢的催化分解进行了一维数值仿真。对过氧化氢催化床的催化性能进行了试验研究,分析了催化床床载、催化床初始温度对过氧化氢催化分解的影响,与一维情况下的数值仿真结果进行了对比。对喷注器类型、喷管等结构进行了试验研究。研究结果表明,采用带后向台阶的横向喷注器比气液同轴剪切喷注器更易于自燃,后向台阶的高度对燃烧室火焰稳定有影响,燃烧室的特征长度越长,越利于自燃。对燃料喷入时的燃烧室温度、压力及推进剂余氧系数等工作参数进行了试验研究。研究结果表明,当推进剂处于余氧系数小于1或略大于1时,在燃烧室压力相同的情况下喷入燃料,燃烧室温度越高,可自燃的余氧系数越小;在燃烧室温度大致相同的情况下喷入燃料,燃烧室压力越高,可自燃的余氧系数越小;在燃烧室温度、压力大致相同的情况下喷入燃料,余氧系数越高,自燃发生的可能性越大。通过本文的工作,验证了过氧化氢自燃点火器的可行性,积累了相关的设计与试验经验,为深入研究该点火器奠定了基础。更多还原

【Abstract】 In the auto-ignition igniter with knock-down subsections that uses decomposed hydrogen peroxide as the oxidizer, the liquid fuel is vaporized and autoignites when injected into the hot decomposition products.Theory of combustion dynamics, Semenov auto-ignition and method of prediction of auto-ignition by the Semenov Equation were introduced in the dissertation. The decomposition process, proven decomposition methods, decomposition evaluation and decomposition model of hydrogen peroxide were discussed. The decomposition process of hydrogen peroxide in a catalyst bed was numerically simulated with a 1-D model.The performance of catalyst beds was experimentally studied. The influence on decomposition was investigated with changing the mass flux through the cross of the catalyst bed and the initial temperature of the catalyst bed. The experimental results were compared with those of the numerical simulation.The influence on auto-ignition of different injectors and nozzles was experimentally researched. The results indicate that auto-ignition occurs more easily when the igniter uses the cross injector with rearward facing step, the height of the rearward facing step influences the stability of the combustion flame, the longer the combustor characteristic length is, the more easily auto-ignition occurs.The effect of the combustor temperature, pressure and coefficient of residual oxygen was experimentally investigated when the fuel was injected into the combustor. The results indicate that with the coefficient of residual oxygen being less than 1 or around 1, when the fuel is injected into the combustor at the same combustor pressure, the higher the combustor temperature is, the less the coefficient of residual oxygen is when auto-ignition occurs; when the fuel is injected into the combustor at the same combustor temperature, the larger the combustor pressure is, the less the coefficient of residual oxygen is when auto-ignition occurs; when the fuel is injected into the combustor at the same combustor temperature and pressure, the bigger the coefficient of residual oxygen is, the more easily auto-ignition occurs.The research shows the feasibility of the hydrogen peroxide auto-ignition igniter. Knowledge and experience of auto-ignition igniter design and test have been acquired, which is a good foundation of further study.更多还原