Study On The Characteristics Of The Secondary Atomization Of The Fire Jet

The fire safety cause is an important part related to people's livelihood.Most firefighting facilities use water as a fire extinguishing medium.In the process of extinguishing fire,the performance of water atomization directly affects the effect of fire extinguishing.The atomization process of high-speed water jet includes primary atomization process and secondary atomization process,and the state of droplets after secondary atomization determines the final atomization quality.Improving atomization quality and finding better atomization conditions have a very constructive effect on the improvement of fire extinguishing efficiency.However,the problems of droplet breakage and atomization of high-speed jets are very complicated,and their breaking characteristics still require in-depth study.Therefore,it is important to study the crushing characteristics of secondary atomization and explain the split phenomenon of secondary atomization.In this paper,the VOF method is used to numerically simulate the secondary atomization of droplets,and the volume change after secondary atomization of droplets is simulated.An experiment platform was set up to conduct the second atomization experiment.According to the experimental results,the droplet breakage law during the second atomization process of the droplets was analyzed in order to better study the mechanism of droplet secondary atomization.The mixture of water and glycerin was used as the medium,and a uniform airflow was used in the glass tube for the experiment.Then based on the breaking process of the secondary atomization of the droplets photographed in the experiment,the characteristics of several breaking modes of the secondary atomization of the droplets were studied.And analyze the various characteristics of droplets secondary atomization law:including the analysis of the crushing angle of droplets after secondary atomization and the crushing characteristics of droplets with the critical We number during the secondary atomization of water;maximum The relationship between the deformation rate and the We number and the law of the change of the deformation rate with the dimensionless time.In the bag mode,the deformation characteristics of the relationship between the bag length and the We number;The relationship,and the characteristics of the time of the change law of the droplet peeling rate in the shear mode are studied.