Experimental study of internal and external field characteristics of spiral nozzle
The hollow nozzle with a spiral flow guide structure on the top of the swirl chamber was studied experimentally.A spray test bench capable of accommodating 1-4 nozzles is set up,and a visual spiral nozzle is manufactured for spray characteristic experiments.High-speed cameras are employed for visualizing the internal flow field characteristics,and the distribution of external flow field spray density is collected through measurement devices.The variations of internal flow field air columns and turbulent flow under different operating conditions,as well as the characteristics of external flow field spray density,are analyzed.The results show that under the influence of internal and external pressure differences,an air column forms inside the nozzle,and due to the effects of the single-side tangential inlet and the spiral guiding structure,the centerline of the air column is offset from the centerline of the swirl chamber.The circumferential effective spray density of the external flow field presents a double-peak distribution,with the peak areas located near 120° and 280° respectively.