超声速燃烧室中煤油分布对燃烧性能的影响

Effect of Kerosene Distribution on Combustion Performance in Supersonic Combustor

关键词:  超声速燃烧室  煤油  支杆  燃烧性能

Key words:  Supersonic combustor  Kerosene  Struts  Combustion performance

摘要:

为研究煤油分布对燃烧性能的影响,在来流马赫数6,总温1650K的条件下,通过改变喷孔数量、喷射方向(单向对喷、双向喷)、喷孔排布方式(单列3孔、4孔)等,实现煤油在燃烧室截面上的不同均匀程度,获得了壁面压力及推力收益等数据。实验表明,单列4孔更易于煤油进入附面层和凹槽内的回流区等低速高温区域,有利于对点火和火焰稳定；对喷时燃烧主要集中在燃烧室核心区,虽可避免壁面承受太大的热载荷,但中部极度富油的状态对总燃烧效果有负面影响；双向喷能够充分利用两个侧壁附近的角落区,在整个燃烧室截面上的分布更均匀,燃烧效果更好,推力收益更大。

Abstract:

In order to study the effect of kerosene distribution uniformity on combustion performance, experiments were carried out by changing the number of injector holes, the direction of injection (one-row and two-row on a strut) and the distribution of kerosene injector holes (3 holes or 4 holes in one-row) in one strut, with the free stream Mach 6 and total temperature 1650K. Some conclusions can be drawn from the analysis of the experimental data in different conditions such as the integrated balance data and the wall pressure distributions:compared to the other two struts, the top holes of the 1×4 strut are nearer to the wall and its bottom holes are closer to the cavity, so the kerosene enters the low-speed and high-temperature zones such as the boundary layer and the circumfluence zone of the cavity more easily, which is helpful for the ignition and steady combustion of the kerosene; for the opposite injection scheme, most kerosene and its combustion are in the core area of the combustor, so the wall heat load is reduced, but too rich fuel has bad influence on the total combustion performance; for the both-side injection scheme, some kerosene is injected into the corner of the combustor wall, which results in more well-proportioned distribution in the cross section of the combustor, so ignition becomes much easier, and better combustion effect and greater net thrust are obtained. 