不同比例放大倍数喷嘴内空穴流动的试验研究

Visualization Experiment of Cavitating flow in Nozzle with Different Amplification

在比例放大透明喷嘴内空穴流动可视化试验台上,采用高速数码摄影和长工作距离显微成像技术,重点研究了不同比例放大倍数喷嘴内部空穴流动图像。试验结果表明:放大三倍喷嘴内部空穴形态呈线性,而放大五倍和八倍喷嘴内部空穴形态呈层状;放大三倍喷嘴没有观察到水力柱塞流现象,而放大五倍和八倍喷嘴内都观察到了水力柱塞流现象;此外,试验中观察到了迟滞现象。

A visualization experiment of cavitating flow with a transparent injector nozzle which can be scaled-up was setup. A high speed CCD camera equipped with a long distance microscope device was used to acquire the flow and spray images of differently amplified nozzles. The experimental results show that the string type cavitation bubble is visible in the nozzle scaled-up by three times, while the cloud type cavitation bubble is obtained in the nozzles scaled-up by five times and eight times. There occurs the phenomenon of hy- draulic plunger in the nozzles scaled-up by five times and eight times. But there is no hydraulic plunger phe- nomenon in the nozzle scaled-up by three times. A hysteretic cavitation was observed in the experiment.