基于Hartmann哨超声喷嘴的雾化特性研究

Atomization Characteristics of Ultrasonic Nozzle with Hartmann Whistle Structure

介绍了一种基于Hartmann哨的超声雾化喷嘴。通过激光粒度分析仪对喷嘴的雾化特性进行了实验研究,分析了不同气压对雾滴索特平均直径(SMD)、雾化角和用水量的影响。对喷嘴加装了中心杆,对比了有无中心杆对于雾滴SMD的影响。研究表明:随着气压的增大,雾滴SMD显著减小,雾化角增大,而气压在0.5 MPa时两者达到极值并趋于稳定;喷嘴加入中心杆,并在气压达到一定值后,雾滴SMD有了明显的减小,最小雾滴SMD可以达到12μm;在气压为0.5 MPa,用水量最少,雾化效果最佳。

Here,we experimentally addressed the atomization characteristics of the ultrasonic nozzle,modified with a thin rod inserted through the axis of its Hartmann whistle. The impact of the inserted rod and compressed airpressure on the key variables,including Sauter mean diameter（ SMD）,atomization angle and water consumption,was investigated with laser particle size analyzer. The results show that the inserted rod and pressure have a major impact on the spraying characteristics. To be specific,as the pressure increased in a range below 0. 5 MPa,SMD dramatically decreased and the atomization angle rapidly increased; and a pressure of 0. 5 MPa optimized and stabilized the atomization,maximized the atomization angle,and minimized SMD and water consumption. The central rod significantly reduced the droplet size. For example,at a pressure higher than 0. 4 MPa,the rod decreased SMD by 3μm,with the smallest droplet being 12 μm.