【作者】 李明；

【导师】 吴晋湘；

【作者基本信息】 河北工业大学 ， 热能工程， 2007， 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。而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。本文提出了一种新型的凹槽结构,在稳焰的基础上增强混合效果。通过数值模拟对超燃冲压发动机燃烧室内混合增强机理进行了研究。通过采用SSTκ-ω湍流模型对凹槽流场数值模拟结果表明:在采用做了压缩性修正和跨音速修正的SSTκ-ω湍流模型计算凹槽流场精度较高,能够捕捉到凹槽内的漩涡、剪切层的分离和重新附着等现象,计算的凹槽壁面压力和试验结果吻合较好。为了使凹槽有更好的增强混合效果,本文设计了一种人字形凹槽,并对这种凹槽与平凹槽进行了对比研究。研究结果显示在人字形凹槽内部产生了流向涡,而流向涡的产生增强了气体掺混。最后在凹槽前喷入氢气模拟结果表明:人字形凹槽比平凹槽在混合效果更好。这是因为与平凹槽相比,人自形凹槽产生了流向涡,把大量空气卷入氢气团内,增强了空气-氢气混合效果,达到了我们的数值模拟目的。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. Cavities have gained the attention of this ramjet community as a promising flame holding device; computations are done on the increasing mixture of scramjet.Through the use of SSTκ-ωturbulence model of cavity flow numerical simulation results show that: use the SSTκ-ωturbulence model of compression amendments and transonic amendment has a high precision, can get the whirlpool, the shear layer separation and re-attachment, and other phenomena, the calculated pressure of cavity wall in good agreement with experimental results. In order to have a better enhance of the cavity mixed results, in this paper, design a herringbone head cavity, and do lots of comparative study between herringbone head cavity and flat head cavity. The results showed that there is a vortex flow follow flow direction in herringbone head cavity, and increasing air mixture.Finally calculated results of injected hydrogen in front of cavity show that: compare with flat head cavity, herringbone head cavity have a better mixture result. This is because there is a vortex flow follows flow direction in herringbone head cavity, and Large quantities of air involved in hydrogen group. Enhanced air - hydrogen mixed results, we reached the numerical simulation purposes.更多还原