喷射压力对喷雾的影响

Effects of injecting pressure on a spray

采用闪光摄影技术,在射流试验台上进行了较低喷射压力范围内瑞利模式液膜射流碎裂过程试验,在喷雾特性试验台上进行了较高喷射压力范围内柴油雾化质量的试验,对2种试验结果进行了比较分析。结果表明:由小宽厚比喷嘴喷射出的瑞利模式低速液膜射流碎裂长度随喷射流速的增大几乎呈直线增加,与喷射压力没有直接关系,喷射压力只有通过喷射流速才对射流碎裂长度产生影响,喷射流速是射流碎裂过程中的稳定因素;雾化模式的喷雾质量随喷射压力的增大显著改善,喷射压力和喷射流速转变成为液体碎裂的不稳定因素。

A Rayleigh mode experiment of liquid film breakup process in lower injecting pressure region on liquid jet injecting test device, and an atomization mode experiment of diesel spray quality in higher pressure region on spray characteristics test device were conducted by photograph technique. A comparison analysis was made between above two experiments. The results indicate that the breakup lengths of a liquid film injected from a smaller aspect ratio nozzle with lower velocities almost linear prolong with injecting velocities increase, and no direct concern with injecting pressures in Rayleigh region. Injecting pressures effects on the liquid jet breakup lengths are only produced by injecting velocities. Injecting velocity is a stable factor on liquid jet breakup process. The spray quality is significantly improved with injecting pressure increase in atomization region, and injecting pressure and velocity become an unstable factor in liquid jet breakup process. 4 tabs, 9 figs, 19 refs.