主燃孔对某小型发动机燃烧室流动及燃烧特性影响

Influence of Primary Combustion Holes on the Flow and Combustion Characteristics of a Small Engine Combustor

以头部涡流片加主燃孔形式的小型发动机环形回流燃烧室为研究对象,采用Fluent软件进行了数值研究,对比分析了有无主燃孔、主燃孔相对位置以及主燃孔轴向位置对该类型燃烧室主燃区流场、温度场以及出口温度分布的影响。结果表明:该类型燃烧室主要通过火焰筒头部圆形结构、涡流片形成回流区,而内外环主燃孔的射流主要起到截断主流、促进回流区形成以及改变回流区形态的作用;主燃孔相互交错,有利于促进内外环主燃孔的射流相互对冲剪切,形成较为饱满的回流区;主燃孔轴向位置向燃烧室出口方向移动,主燃孔射流截断主流和挤压主流的效果减弱,出口温度分布系数急剧变大。

Taking the small engine annular reverse-flow combustor in the form of head vortex plates and primary combustion holes as the research object,the numerical research was carried out by using Fluent software.And the influences of the presence or absence of primary combustion holes,the relative position and the axial position of primary combustion holes on the flow field,temperature field and outlet temperature distribution in the primary combustion zone of this type of combustor were compared and analyzed.The results show that this type of combustor mainly forms the reverse-flow zone through the circular structure of the flame barrel head and the vortex plates,while the jet flow from the primary combustion holes of the inner and outer rings mainly plays the role of cutting off the primary flow,promoting the formation of the reverse-flow zone and changing the shape of the reverse-flow zone.The primary combustion holes are staggered with each other,which is conducive to promoting the mutual jet impingement and shearing of the primary combustion holes in the inner and outer rings,forming a relatively full reverse-flow zone.The axial position of the primary combustion hole moves towards the outlet of the combustor,the influence of the primary combustion hole jet cutting off and squeezing the primary flow is weakened,and the outlet temperature distribution factor becomes larger sharply.