摘要
基于超声雾化和载气输运技术,设计了速度、全局当量比可独立控制的碳氢燃料多液滴流制备系统。所生成的多液滴流能够更加真实地模拟内燃机喷雾外围液滴群的流动与混合状态。采用高亮度LED光源,并从90°角度拍摄多液滴流散射光,获得了不同空气流量(10、20、30、40L/min)和正庚烷供给速度(150、200、250、300mL/h)下的多液滴流高速摄影图片。发现多液滴流离开喷嘴管出口后可保持一段时间的单向稳定流动。空气卷吸和液滴挥发的共同作用导致稳定段长度随出口速度升高而先增大后减小。当喷嘴管出口液滴流速度低于5.2m/s时,在稳定段之后将出现明显的空气卷吸漩涡,而且出口速度越低,漩涡越多且形状更加规则。离喷嘴管出口较远时,液滴扩散范围增大和燃料挥发可能导致采用散射光法已逐渐无法观测到多液滴流。
An experimental fuel based on the ultrasoni equivalence ratio of the s mixing conditions of the d multi-droplet stream creating system was developed for the hydrocarbon c atomization tream could roplets at the and the carrier-gas transport techniques. The speed and global be controlled independently to simulate really the flow and spray fringes. The stream scattering light was photographed by a high-speed camera at 90~ angle using a high intensity LED light source under different air flow rates（10,20,30 and 40 L/min） and different n-heptane supply rates（150,200,250 and 300 mL/h）. The pictures showed that there was a stable flow near the nozzle exit and its length increases firstly and then decreases with air flow increasing because of the combined effect of air entrainment and droplet vaporization. When the stream speed at nozzle exit was lower than 5. 2 m/s, appeared the obvious air entrainment eddies after the stable sector, and the lower the speed, the more eddy numberand the more regular the eddy form. droplet stream might not be shot by vaporization. When the stream its scattering at was far away from the n 90°angle because of the ozzle exit, the multi droplet diffusion and
出处
《吉林大学学报（工学版）》
EI
CAS
CSCD
北大核心
2012年第4期871-876,共6页
Journal of Jilin University:Engineering and Technology Edition
基金
国家自然科学基金项目(51106113,51006075,51076118)
关键词
动力机械工程
超声雾化
多液滴流
正庚烷
散射
power machinery and engineering
ultrasonic atomization
multi-droplet stream
n-heptane
scattering
