双路离心式喷嘴液膜形态的实验研究

Experimental Study on Liquid Film Morphology of the Dual-orifice Swirl Nozzle

借助高速运动分析系统对不同工况条件下双路离心式喷嘴液膜形态进行深入研究,重点分析了主、副油路单独供油与同时供油时液膜的形成与破碎机理.结果表明,副油路液膜形成过程分为射流、成膜、展开3个阶段,主油路液膜形成过程为聚集、成膜、展开3个阶段.副油路介质流动会提升主油路开启时主油路介质的雾化效果.主、副油路液膜的破碎分为初级破碎与二级破碎2个过程,其中主油路的液膜的初级破碎可按是否有孔洞形成分为2类.副油路液膜存在周期性摆动现象,摆动过程会使得液膜破碎长度减小,雾化效果提升.随着背压差的增加,液膜摆动时长占振动周期的百分比增加,雾化效果提升.研究结果有助于揭示双路离心式喷嘴的流动机理并提供设计指导.

In this paper, a high speed fluid motion analysis system was used to investigate the liquid film morphology of the dual-orifice swirl nozzle deeply, especially on the formation and breakup mechanism of the liquid film. It was found that the liquid film formation of pilot line was divided into three stages, including jetting, forming and unfolding, while the liquid film formation of main line was divided into three stages, including clustering, forming and unfolding. The spray medium flow of the pilot line increased the atomization characteristic of the main line when the main line was open. The liquid film breakup process of main and pilot line liquid is divided into two stages, including primary breakup and secondary breakup. The liquid film primary breakup of the main line can be divided into two types according to holes on the liquid film. The liquid film of pilot line was disclosed to swing periodically. The swinging process reduced the breakup length of the liquid film and improved the atomization characteristic. With the increase of the pressure, the ratio of swinging duration of liquid film to vibration period increased. The results benefit to provide guidance for the disclosure of the flow mechanism and the basic design of the dual-orifice swirl nozzle.