小流量旋流喷嘴喷雾性能影响因素的试验研究

在超高压燃油喷雾试验台上测试分析了不同环境背压及喷射流量对适用于斯特林发动机的小流量压力旋流喷嘴燃料喷射性能的影响。结果表明:喷嘴的喷雾形态受燃烧室背压的影响最明显,背压升高,喷雾锥角减小;喷射流量的影响受背压的限制,中高背压下,流量增大到一定程度后锥角开始变小,流量继续增大,雾化效果变差。喷嘴设计流量的影响为:增大设计流量,相同工况下的喷雾锥角有增大的趋势,但有效雾化的最小临界流量值变大;设计锥角的影响和设计流量类似:较大喷射流量工况下,大设计锥角喷嘴对高背压的适应性较好。研究认为:小流量工况只能采用小设计流量的喷嘴,且对高背压的适应性较差;在大流量工况下,设计流量和设计锥角均较大的喷嘴对高背压工况具有更好的适应性。

Experimental Study on the Influencing Factors of Spray Performance ofSmall Flow Centrifugal Swirl Nozzle

The effect of ambient pressure and spray flow on fuel injection performance of small flow centrifugal swirl nozzle was investigated on an ultra-high pressure fuel spray test bench. The results show that the shape of spray is mostly affected by ambient pressure, the increase of ambient pressure leads to the decrease of spray cone angle; the effect of spray flow is restricted by ambient pressure, when under medium or high ambient pressure, increase of spray flow leads to a drop in spray angle, as the spray flow keep increasing, the atomization effect would get worse. The effect of nominal spray flow is:larger nominal spray flow may lead to the increase of cone angle under the same working condition, while its critical spray flow also grows larger; the effect of nominal cone angle is similar with that of nominal spray flow, and a larger nominal cone angle leads to a better adaptation to high ambient pressure with large spray flow. The research shows that with small spray flow, nozzles with small nominal spray flow are recommended; at large spray flow working conditions, nozzles with large nominal spray flow and cone angle are recommended, with a better adaptation to high ambient pressure.