入口非均匀流对亚燃燃烧室性能影响数值研究

为研究人口非均匀流对亚燃燃烧室性能的影响，基于进气道出口试验测量数据，构造三种典型非均匀流型，对燃烧室进行三维数值计算，研究非均匀流对马赫数分布、温度场、燃油分布及燃烧效率的影响。结果表明：基于均匀流供油律，非均匀流影响燃烧室性能的机理是受流速主导作用，低速区域当量比偏高，高速区域当量比偏低。导致扩压段边区燃烧，烧蚀外环阻塞结构，而内圈高速区域燃烧组织效果欠佳。匹配供油律后，非均匀流燃烧性能有所改善，但难以达到均匀流水平。所以，提出了改进入口流均匀性及减弱非均匀流对燃烧不良影响的措施。

Numerical Investigation on Performance of a Ramjet Combustion Chamber with Nonuniform Inlet Flows

Based upon analyzing experiment data of air intake outlet, three types of nonuniform mass flux profile are constructed to investigate the impact on the chamber performance. A 3D numerical study of chamber flow is performed with these three profiles. The effects on Mach number distribution, temperature field, fuel distribution and combustion efficiency are studied. The results show that the nonuniform velocity caused by nonuniform mass flux is the essential effecting factor, together with the uniform fuel-feeding rule, the distribution of equivalence ratio is bad. The effecting mechanism is the equivalence ratio is higher in low speed area and lower in high- speed area. Low speed areas with higher equivalence ratio make the boundary zones of diffuser combust earlier and take a risk of burning the outer blockage structure. High-speed areas with relatively lower equivalence ratio lead to worse combustion effect. After adjusting the fuel-feeding rule, performance with nonuniform flow is im- proved, but hard to reach the level of uniform flow. Strategies of improving inlet flow uniformities and combustion quality are presented in the end.