低压环境下过热流体喷雾特性实验

Experimental Investigation on Spray Characteristics from Superheated Liquid Jets under Low Pressure

关键词:  过热度  长径比  索特尔平均直径  泡点温度  经验关系式

Key words:  Superheat degree  Ratio between nozzle length and diameter  Sauter mean diameter  Bubble point temperature  Empirical correlation

摘要:

为了研究低压环境下燃料的过热度、喷射压力和喷嘴几何结构对喷雾形状和液滴索特尔平均直径等喷雾特性的影响,测量了不同环境压力下的煤油泡点温度,并给出了环境压力和泡点温度的经验关系式。将过热的航空煤油通过直射式喷嘴喷入低压容器中,进行了不同喷射条件下的喷雾实验。使用高速摄影仪和激光粒度仪进行拍摄和测量,得到了一系列的粒子索特尔平均直径数据和喷雾图片。结果表明,过热度的增加、喷射压力的增加和喷嘴长径比的减小都能够改善煤油的喷射雾化效果。

Abstract:

Experiments were carried out to investigate the influences of superheat degree, aviation kerosene injection pressure and spray nozzle geometry on spray form and Sauter Mean diameter(SMD) by the ejection of aviation kerosene into a vacuum chamber through long nozzles using a high-speed camera and laser particle size analyzer. Kerosene bubble point temperature under different ambient pressure was measured and the empirical correlation between kerosene bubble point temperature and ambient pressure was developed by fitting data. And then, a series of SMD and spraying pictures were obtained by spray experiments under different conditions. The results show that atomization could be improved by increasing superheat degree and injection pressure or decreasing the ratio between nozzle length and diameter remarkably. 