喷油杆和凹腔支板稳定器近距匹配的液雾分布可视化

液雾分布与稳定器的燃油布置方式、油气分配、火焰稳定及火焰传播密切相关。以RP-3为雾化介质，在来流马赫数为0.2及来流温度为10~400℃的条件下，采用高速摄影法和激光片光/照相法，对喷油杆与凹腔支板稳定器间隔31.5 mm且顺喷时的液雾分布特点进行了可视化研究，并探讨了来流温度及油气动量比对其液雾分布轨迹的影响。结果表明:顺喷喷油杆与凹腔支板稳定器近距匹配方式有利于燃油在支板前缘形成挡溅雾化；挡溅雾化后的一部分燃油在支板表面形成油膜，并在凹腔前缘与尾缘进行二次雾化，来流温度较高时高温支板表面也有利于燃油的蒸发雾化；另一部分燃油则以类似横向射流的形式进行雾化。当来流温度一定时，油气动量比增大，液雾轴向分布距离和横向穿透深度均增大；来流温度升高，液雾穿透深度增加，油气动量比对液雾分布的影响更明显。 

Visualization on spray distribution of close-coupled fuel injector and strut with cavity flameholder system

Spray distribution is closely related to the fuel supply methods, fuel-air distribution ratio, flame stability and flame propagation properties of flameholders. Taking RP-3 as atomization medium, the spray distribution characteristics of close-coupled fuel injector and strut with cavity flameholder system were visualized by high-speed photography and laser sheet/photography, under the condition of incoming flow Mach number 0.2, incoming flow temperature varying from 10℃ to 400℃, the distance of fuel injector and stabilizer kept as 31.5mm and the downstream injection direction. Meanwhile, the effects of incoming flow temperature and fuel-to-air momentum flux ratio on spray distribution trajectory were studied as well. The result showed that, downstream injection close-coupled fuel injector and strut with cavity folder system was benificial to the fuel atomization by splashing fuel jet at the leading edge of strut. After the splashing, a part of fuel was distributed on the surface of strut as fuel film and atomized further at the leading edge and trailing edge of cavity, during which higher incoming flow temperature led to faster evaporation. And another part of fuel spray was atomized as cross-flow. Under the same incoming flow temperature, the axial-direction distribution distance and cross-direction penetration depth of spray increased with the fuel-to-air momentum flux ratio. With the increase of air incoming flow temperature, penetration depth increased and fuel-to-air momentum flux ratios effect to spray distribution became more obvious.