【作者】 余勇；

【导师】 王振国；

【作者基本信息】 国防科学技术大学 ， 航空宇航科学与技术， 2004， 博士

【摘要】 本文综合运用理论分析、试验研究和数值模拟等多种手段,对煤油燃料超燃冲压发动机燃烧室的性能分析评价方法、方案设计及其优化、点火燃烧性能及其影响因素、内流场结构及其特点进行了系统深入的研究,取得了很多有意义的成果。 提出了超燃冲压发动机燃烧室的性能分析评价方法。开发了燃烧室两相多组分一元反应流分析程序,为超声速燃烧室方案设计阶段的快速性能评估与设计优化提供了一种有效的手段。 在燃料射流穿透度概念的基础上,提出了燃料射流相对穿透度的概念,并将其成功应用于发动机点火燃烧性能的分析。 进行了338次相同模拟条件、不同发动机点火方式、结构和工作参数下的超燃冲压模型发动机试验,对煤油燃料超燃冲压发动机燃烧室的点火燃烧性能及其影响因素进行了系统的研究。结果发现,利用全高度支板前缘产生的斜激波可以实现煤油的自燃着火和稳定燃烧,但支板太厚可能致使燃烧室壅塞。利用半高度后掠支板和氢气引导火焰相结合的点火方式,也可以实现煤油的可靠点火和稳定燃烧。由于受射流相对穿透度影响,氢气引导火焰的点火特性和燃烧室尺度有关,表现出明显的尺度效应。当利用点火器强制点火时,存在一个能够点火的能量阈值。煤油能够维持稳定燃烧且不出现热壅塞的当量比范围与点火方式和燃烧室构型等因素密切相关。燃料喷注压降和当量比、燃料喷嘴位置、燃料射流相对穿透度、点火方式、燃烧室结构、凹腔火焰稳定器结构等因素影响发动机燃烧室燃烧性能。更多还原

【Abstract】 The performance analysis and evaluation method, schematic design and optimization, ignition and combustion performance and their relative conditions, internal flow field and its characteristics of kerosene fueled scramjet combustor are studied detailedly and comprehensively by means of theoretical analysis, experimental investigation and numerical simulation. Many results are obtained.The methodology for scramjet combustor performance analysis and evaluation is build up. A computer program for two phases, multi species, chemical reacting flow analysis and computation in scramjet combustor is worked out. This provides an effective means for rapid performance analysis and design optimization of scramjet combustor.Based on the concept of penetration depth of fuel jet, the concept of relative penetration depth of fuel jet is presented. This concept is applied successfully in the ignition and combustion performance analysis of the scramjet model.Three hundred and thirty eight scramjet model experiments in same simulation flying conditions were conducted in the conditions of different ignition method, different structural and working parameters. The ignition and combustion performance of kerosene fueled scramjet combustor are studied detailedly and comprehensively. The kerosene was ignited by the oblique shockwave induced by the leading edge of the full height strut and stable combustion was sustained. But too thick strut can make the combustor choke. Combination use of the oblique Shockwave induced by the leading edge of the half height strut and hydrogen pilot flame can also ignite the kerosene and hold the combustion stably. Because of the relative penetration depth of the fuel jet, the ignition performance of hydrogen pilot flame has relations with the combustor scale. There is an energy threshold value beyond which kerosene can be ignited by the igniters. The equivalent fuel/air ratio range in which the kerosene can combust stably without choking has close relations with the ignition method, the structural parameters of the combustor, etc. Many parameters, such as the fuel jet pressure drop, the equivalent fuel/air ratio, the position of the fuel injectors, the relative penetration depth of the fuel jet, the ignition method, the structural parameters of the combustor, the structural parameters of the cavity, and so on, do have influences on the combustion performance of the scramjet combustor.更多还原