固体燃料超燃冲压发动机燃烧室初步实验研究

Preliminary Experimental Investigation of Solid Fuel Scramjet Combustor

设计并搭建了一个小型直连式试车台,开展了固体燃料超燃冲压发动机燃烧室工作过程的初步实验研究。加热器提供的燃烧室入口总压与总温分别为2.2MPa与1600K,试验证明了固体燃料超燃冲压发动机燃烧室在没有外部辅助条件下能够实现自点火和稳定燃烧。实验结果表明,燃面退移速率沿轴线先增大后减小,在凹腔和等直段交界处达到最大值,其峰值超过2 mm/s。随着燃烧进行,燃烧室通道扩大,凹腔与等直段压强下降较快。由于扩张比逐渐减小,扩张段内压强变化比较平稳。实验研究了采用突扩台阶进行火焰稳定的燃烧室构型,结果表明突扩台阶不适合作为固体燃料超燃冲压发动机的火焰稳定器。

A direct-connect static test-firing facility has been designed and built to carry out a preliminary experimental study on work process of solid fuel scramjet combustor. The stagnation pressure of 2.2MPa and stag- nation temperature of 1600K were provided at combustor inlet by a air heater. With this test facility, the self-ig- nition and sustained combustion were demonstrated under supersonic crossflow conditions in a scramjet configura- tion with no external aid. The results show that the regression rate increases first then decreases along the axial di- rection, and the maximum rate is located at the joint of cavity and cylindrical section, which is greater than 2 mm/s. As the combustion goes on, the fuel port diameter increases and static pressure drops fast in cavity and cy- lindrical section. Because the expansion ratio of diverging section decreases, the variation of static pressure in di- verging section is smooth. Another combustor configuration with a sudden expansion step for flame-holding was investigated experimentally. The results show that the sudden expansion step is not suitable for flame-holding in solid fuel scramjet.