单头部燃烧室流场PIV试验测量

航空发动机燃烧室内流场结构直接影响燃油雾化、油气掺混以及燃烧性能,本文采用粒子图像速度仪(Particle image velocimetry,PIV)对某单头部基准燃烧室内的冷态流场和燃烧流场分别进行了试验测量。在冷态流场试验中,研究了进口空气流量变化对燃烧室内的流场结构、回流区尺寸大小变化的影响规律;而燃烧流场试验测量分别研究了进口空气流量和油气比变化对燃烧流场结构的影响。试验结果表明:由于下壁面中间主燃孔进气射流的强烈影响与挤压,导致旋流器出口处横向截面上的旋转气流不是一个完整的旋流气流;燃烧流场与冷态流场相比,其流场结构基本相似,但中心回流区宽度稍变瘦,随着油气比的增大,中心回流区逐渐变瘦,宽度变窄;随着油气比的增加,轴向速度逐渐变大、回流负速度变大;燃烧流场测量中,在燃烧室头部较好地捕捉到喷嘴喷出的油雾锥上油珠的速度大小。

Flow Field Investigation in Single-Dome Combustor Using Particle Image Velocimetry

The fuel atomization, fuel-air mixing and combustion performance can be directly affected by the structure of flow field in aero-engine combustor, therefore, the cold flow field and combustion flow field in a single-dome combustor are investigated by using Particle Image Velocimetry (PIV) in this paper. Influences of different inlet air flow rates on the area and the structure of re-circulation zone for the non-reacting flow fields are investigated experimentally separately. Moreover, influences of different inlet air flow rates and the fuel-air ratios on the structure of the combustion flow field are also studied experimentally. The experimental results show that the swirling flow at the cross section of the swirler''s outlet is not complete due to the strong influence of the air jet from the primary hole on the bottom wall. The flow field structures for the cold flow and the combustion flow are similar, but the width of central recirculation zone for the combustion flow field is thinner compared with that of the cold flow field. With the increase of the fuel-air ratio, the width of central recirculation zone becomes narrower, the axial velocity becomes larger and the negative velocity of recirculation increases. At the same time, the fuel droplet velocity of the atomization cone can be captured in the dome of combustor during the measurement process of combustion flow field.