Fundamental Study on Scram Jet Engines

超燃喷气发动机基础研究

• 批准号: 02302037
• 负责人: KAJI Shojiro
• 金额: $ 13.95万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Co-operative Research (A)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02302037/
• 关键词: Aerospace propulsion; SCRAM jet engine; Supersonic air intake; Turbulent diffusion; Supersonic combustion; Heat pipe; Ceramics

In order to realize the SCRAM jet engine which is the most promising propulsion system for space planes and hypersonic transports, this research project aims at fundamental study in the four important fields :(1) Air intake, (2) Fuel injection and mixing, (3) Supersonic combustion, and (4) Thermal protection structure and materials.(1) In the air intake research the focus was put on the stable operation of inlets, and compound choking phenomena due to sucking of airframe boundary layer flows into engine and transient unstart and restart phenomena were investigated. Results show that the airframe boundary layer flow easily leads engines unstart, but that the swept side cowl inlet easily recovers from unstart to restart.(2) The study on fuel injection and mixing progressed understandings on flow mechanics and turbulent mixing process of fuels injected into a supersonic stream. Two-dimensional as well as three-dimensioanl injection experiments were conducted, and the correlation between mixing efficiency and total pressure loss were clarified. Numerical simulation technique for a two-dimensional injection model was established.(3) The purpose of supersonic combustion is first to realize combustion of hydrogen in the supersonic stream, and secondly to study importance of factors which control supersonic combustion processes. In the experiments parallel-to-flow injection as well as normal-to-flow injection were adopted, and the effect of combustion on flow mechanics were made clear via optical observation on the structure of shock waves and flames.(4) In the field of thermal protection structure and materials, a high performance cooling structure was constructed applying the heat pipe concept to a two-dimensional panel, and its basic characteristics were studied. In the research for high temperature materials, the fracture mechanics of ceramics were investigated especially on the relation between the strength of grain boundaries and temperature.

为了实现SCRAM喷气发动机，这是空间平面和高音运输的最有前途的推进系统，该研究项目旨在在四个重要领域的基本研究中进行基本研究：（1）空气摄入量，（2）燃料注入和混合，（3）超音速燃烧，（3）超级保护和（4）在空气中进行的焦点。研究了机身边界层流入发动机，并研究了瞬态解开和重新启动现象。结果表明，机身边界层流动很容易导致发动机脱离，但是扫描的侧围围入口很容易从UNSTART恢复到重新启动。（2）关于燃料注入的研究和对流动力学和注射到超音速流的燃料的湍流混合过程的混合理解。进行了二维以及三二剂注射实验，并阐明了混合效率与总压力损失之间的相关性。 （3）超音速燃烧的目的是首先实现氢在超音速流中的燃烧，其次是研究控制超音速燃烧过程的因素的重要性。在实验中，采用了平行至流量注射以及正常向流向注入的实验，通过光学观察对冲击波和火焰的结构进行了清晰的燃烧对流动力学的影响。（4）在热保护结构和材料领域中，将高性能冷却结构构建到两二维的Panel和Panel and It Contentials and It Contentials and It Contentials and It Contentials and It Contuctiation and It and ITS PANELECTIOS。在高温材料的研究中，研究了陶瓷的断裂力学，尤其是关于晶界强度与温度之间的关系。