Flow field and spray of a high shear air-blast nozzle
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摘要: 采用数值和实验方法对一种强剪切空气雾化喷嘴的流场和喷雾特性进行研究.采用粒子动态分析仪(PDA)实验研究了不同气液比下强剪切空气雾化喷嘴的速度场和喷雾场,并对该喷嘴的流场进行了数值计算,所得的计算结果与实验数据比较吻合.研究结果表明:强剪切空气雾化喷嘴的设计合理,两股旋流空气在喷嘴内部完成强烈的动量交换,并对燃油进行了强剪切.强剪切空气雾化喷嘴在宽调节比范围内能够完成良好的雾化,当气液比变化10倍,液雾的索太尔平均直径分布均处于20~60μm之间.随着气液比的增大,线平均索太尔平均直径逐渐减小,推导了适用于该喷嘴的索太尔平均直径计算模型,可为强剪切空气雾化喷嘴设计提供参考.Abstract: The flow field and spray characteristics of a high shear air-blast nozzle were investigated numerically and experimentally. Particle dynamics analyzer (PDA) was employed to experimentally study on the velocity field and spray field of the high shear air-blast nozzle under different air-liquid ratios. And through numerical calculation of the flow field of the nozzle, the calculated results agreed with the experimental data. The results show that the design of high shear air-blast nozzle is reasonable. Two swirl air flows could finish strong momentum exchange inside the nozzle, and fuel is highly sheared. The high shear air-blast nozzle can achieve good atomization under wide regulation ratios. When the air-liquid ratio is of 10 times, the Sauter mean diameter distribution of spray is between 20-60μm. With the increase of air-liquid ratio, line averaging Sauter mean diameter decreases. The calculation model of Sauter mean diameter is derived for the nozzle. The results can provide references for high shear air-blast nozzle design.
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Key words:
- high shear air-blast nozzle /
- PDA /
- flow field /
- spray characteristics /
- wide regulation ratio
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