【作者】 肖隐利；

【导师】 乐嘉陵；

【作者基本信息】 西北工业大学 ， 航空宇航推进理论与工程， 2005， 硕士

【摘要】 超声速燃烧冲压发动机是一种新型的吸气式动力装置,因其良好的性能和巨大的潜在优势,在未来的军事和民用的航空、航天领域中具有广阔的应用前景。在过去的几十年中,人们对超燃冲压发动机技术进行了大量的试验、理论及数值计算研究。 燃料喷射、增强混合和火焰稳定是超音速燃烧的最基本的难题,也是碳氢燃料超燃冲压发动机设计的重大挑战。为了在尽可能短的燃烧室内实现高效率燃烧,需要采用优化的喷射方案使燃料和空气快速混合、点火可靠并实现稳定燃烧,同时保证总压损失足够小。 在过去几年里,由于在地面试验中的可行性验证和飞行试验中的成功应用,凹槽作为一种有潜力的火焰稳定器引起了超燃冲压发动机研究领域的广泛关注。 本文总结了过去研究者对高速和低速气流中所使用凹槽的流场特征研究成果,讨论了影响用于超音速燃烧室的凹槽火焰稳定器性能的问题,探讨了凹槽流场的计算方法,对各种构型的凹槽流场进行了数值模拟,最后对有凹槽的超燃燃烧室流场进行了数值模拟。研究表明:在燃烧室合适的位置设置凹槽,可以增强燃料的穿透深度,提高燃料的扩散效果,有助于碳氢燃料的点火和火焰稳定。研究成果对定量认识凹槽超燃流场、设计高效率的火焰稳定器、优化凹槽构型具有一定的借鉴作用。更多还原

【Abstract】 The scramjet is a new type of air-breathing propulsion device, which has remarkable performance and great potential superiority, and has a good prospect in the field of military aviation in the future. A number of experimental, theoretical and computational studies have been conducted to explore the Scramjet techniques in the past decades.Fuel injection, mixing enhancement, and flame holding are fundamental aspects of supersonic combustion, and critical to the development of a hypersonic air breathing propulsion engine. To achieve efficient combustion within a manageable length, a successful fuel injection scheme must provide rapid mixing and stable combustion between the fuel and airstreams. At the same time, the introduction of fuel into the combustor must be carried out in such a way that the air stream suffers acceptable total pressure losses.During the last few years, cavities have gained the attention of the scramjet community as a promising flame holding device, owing to the results obtained in flight tests and feasibility demonstrations in laboratory scale supersonic combustors.In this paper, the flow field characteristics of cavities and research efforts related to cavities employed in low and high speed flows are summarized. Open questions impacting the effectiveness of the cavities as flame holders in supersonic combustors are discussed.Firstly, the methods of supersonic flow field numerical simulation about cavity are discussed in this paper. Secondly, the flow field properties of various cavity geometric features are computationally evaluated under Mach 3 flow conditions. Thirdly, the computational study of ethylene fueled scramjet combustor employing cavity flame holder has been performed. The results of calculation show that the flame holding range of supersonic combustor can be enlarged and the combustion efficiency is improved by using cavities. Such information contributes to further understanding the flow field of hydrogen and hydrocarbon supersonic combustion, and is valuable for designing a high performance cavity flame holder in scramjet.更多还原