针对斯特林发动机小负荷燃油雾化不良问题,提出了基于鼓泡-引射耦合的雾化方式.基于VOF(Volume of Fluid)仿真研究了鼓泡喷嘴内气液流态,并依据时间线性稳定性分析,对射流液膜失稳和破碎进行数学描述,建立了鼓泡-引射耦合下的初次雾化模型.分析了气液质量比 RGL(gas-liquid mass ratio)、负荷对初次雾化的影响,并与传统雾化方式比较.结果表明:增大 RGL 会促进射流失稳、减小液滴粒径.相较于传统雾化方式,鼓泡-引射耦合下小负荷索特平均直径SMD减小约62%,雾化质量显著提高.
Aiming at poor atomization under a low load in the Stirling engine,an atomization method based on bubble-ejection coupling was proposed.Based on the VOF(Volume of Fluid)model,the air-liquid flow in the bub-bling nozzle was studied numerically.According to temporal stability analysis,the instability and breakup of liquid sheet were mathematically described,and the model of primary atomization under the bubble-ejection coupling was established.The effects of RGL(gas-liquid mass ratio)and load on primary atomization were analyzed and com-pared with those by the traditional atomization method.The results showed that increasing RGL promotes liquid sheet instability and decreases droplet diameter.Compared with the traditional atomization method,SMD(Sauter mean diameter)at bubble-ejection coupling decreases by about 62%,and the atomization quality is significantly improved.