低压下蒸发式稳定器结构对燃烧效率的影响

在低压条件,对蒸发式稳定器结构进行了优化,对不同方案开展了冷、热态流场三维数值研究,分析了稳定器后方冷态流场、燃油浓度场和热态流场、温度场特点。分析认为,在原蒸发式稳定器基础上,通过增大稳定器一次风进气量和U型蒸发管的长度,可以促进油气的掺混,增大回流区范围,同时采用断续进气,并将蒸发管出气孔与二次风夹角由90°减小到37.5°,可以进一步强化回流效果。最终得到的稳定器模型可以在0.08 MPa的压力条件下,将原稳定器燃烧效率由0.820提高到0.977。

Influence of Vaporizing Flame Holder Structure on Combustion Efficiency at Low Pressure

The design of vaporizing flame holder at low pressure and the three-dimensional numerical studies for both the cold and reacting flow fields in the model chamber of an integrated liquid-fuelled ram- jet have been performed in this thesis. The presented calculation show that increasing the head air quanti- ty of flame holder and the length of the evaporation tube could improve the vaporization and mixing process and enlarge the area of recirculating region. Reducing the angle between exhausting hole and the second wind from 90° to 37.5° could make the effect better. The calculated results show that the combus- tion efficiency of the final model has been improved from 0. 820 to 0. 977 at pressure of 0.08 MPa.