Influence of microwave on structure of supersonic combustion flame [微波对超声速燃烧火焰结构的影响]

作者：Meng Y.; Gu H.^*; Zhang X.

来源：Acta Aeronautica et Astronautica Sinica, 2019, 40(12): 123224.

DOI：10.7527/S1000-6893.2019.23224

• Flame boundary
• Flame structure
• Fractal geometry
• Microwave
• Scramjet
• Supersonic combustion

Plasma assisted combustion in supersonic flow is a promising method. The effect of microwave on the flame structure is studied by feeding low-power microwave into the combustor of the scramjet. The combustor inlet flow Mach number is 2.5. Room temperature ethylene is injected perpendicular to the combustor wall. Single stage cavity is used as flame stabilizer, and 500 W and 700 W continuous 2.45 GHz microwave are added into the combustor. A high-speed camera is used to capture flame CH* illuminating images. After the addition of microwave, the stable position of the flame changes from cavity shear layer flame to jet flame, which indicates that the microwave has an effect on the flame propagation speed or the combustion reaction rate. Using the method of flame boundary extraction and fractal geometry, this paper finds that microwave can increase the fractal dimension of flame boundary, indicating that the propagation rate of flame increases due to the addition of microwave. The paper concludes that a low power of microwave can assist supersonic combustion.

• 单位
  高温气体动力学国家重点实验室; 中国科学院大学