Experimental investigation on spray characteristics from superheated liquid jets under low pressure

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.