采用离轴脉冲激光全息诊断技术,在发动机试车台上对某型号涡轮发动机喷嘴在常温常压及高温纯空气来流条件下的燃油雾化参数进行了实验测量,获得了雾化场空间结构特征、雾化粒子空间位置、数量分布以及索太尔平均直径分布等三维量化数据。实验结果表明,常温常压条件下,该型号喷嘴形成的雾化场呈空心圆锥体分布,雾化粒子集中分布在锥体表面,粒子直径多在60~80 μm之间,随距喷嘴距离的增加,粒子直径减小且趋近一致,表现出均匀的雾化效果;喷射压力较低时,近喷嘴区域密集涡流环下游出现一个类似主流环的涡流环,随着喷射压力的增大,喷嘴附近涡流环数量减少,液膜波纹及细丝增多,下游没有观察到主流环;射流两侧的雾化结构呈现不完全对称分布。在800 K、5.5 kPa的高温纯空气来流作用的工况条件下,燃烧室内雾化粒子的平均直径减小至12 μm左右,雾化质量得到明显改善。

For investigating the fuel spray characteristics of the nozzle designed for the aero-engine, the off-axis particle field holographic measuring system is used on an engine test-bed. The spray structure, atomized particles locations, amounts, and sizes distribution in space under different experimental conditions are obtained quantitatively. Experimental results show that under normal temperature and pressure conditions, the atomization field formed by this type of nozzle is distributed in a hollow cone. The atomized particles are concentrated on the surface of the cone. The diameter of the particles is mostly between 60 μm and 80 μm, with the distance from the nozzle increases, the particle diameter decreases and approaches the same, showing a uniform atomization effect. When the injection pressure is low, a vortex ring similar to the mainstream ring appears downstream of the dense vortex ring near the nozzle area. As the injection pressure increases, the number of vortex rings near the nozzle is reduced, the ripples and filaments of the liquid film are increased, and the mainstream ring is not observed downstream. The atomization structure on both sides of the jet is not completely symmetrical. Under the working conditions of 800 K and 5.5 kPa high temperature pure air flow, the average diameter of atomized particles in the combustion chamber is reduced to about 12 μm, and the atomization quality is significantly improved.