固体燃料冲压发动机旋流燃烧特性数值研究

Numerical study on the swirl flow combustion characteristicsof solid fuel ramjet

关键词:  固体燃料冲压发动机  旋流  计算流体动力学  燃烧性能

Key words:  Solid fuel ramjet  Swirl flow  Computational fluid dynamics  Combustion performance

摘要:

为了研究固体燃料冲压发动机旋流燃烧特性,使用数值模拟方法计算了不同旋流数下的燃速、燃烧效率、推力与比冲。固体燃料为丁羟,燃烧采用总包反应与涡团耗散模型。当旋流数小于临界旋流数时,无需将旋流器出口伸入燃烧室,突扩台阶回流区即可稳定火焰；当旋流数大于临界旋流数后,须将旋流器出口伸入燃烧室一段距离,使火焰稳定在这一段区域内。旋流状态燃烧效率低于直流状态,在考虑了旋流产生的总压损失后,发动机推力与比冲也低于直流状态。

Abstract:

In order to study the swirl flow combustion characteristics in the solid fuel ramjet, the swirl flow field in the solid fuel ramjet combustion chamber was numerically simulated under different swirl numbers. HTPB was applied as solid fuel, the overall reaction process and Eddy-Dissipation Model were adapted. The results showed that if the swirl number is smaller than a critical value, the dump step can hold the swirl flow flame; otherwise, the outlet of the swirl must insert into the combustion chamber in order to hold the swirl flow flame. The swirl flow combustion efficiency was lower than the straight flow, the thrust and specific thrust were also lower than the straight flow, taking account of the total pressure loss.