Experimental analysis of internal flow and spray characteristics of flow focusing/blurring nozzle

This study utilizes a visualization nozzle and spray experimental platform to experimentally investigate the flow focusing/blurring nozzle. It is found that the working mode of the nozzle transitions from flow focusing to flow transition and eventually to flow blurring as the gas flow rate increases or the tube hole distance decreases. Conversely, an increase in liquid flow rate only facilitates the transition from flow focusing to flow transition. Changes in the gas/liquid flow rate or tube hole distance influence the gas shear effect and the gas inertial impact effect inside the nozzle, which in turn alters the working mode. An increase in gas flow rate results in a shift of the droplet size distribution towards smaller particle sizes in the flow blurring mode, whereas an increase in liquid flow rate produces the opposite effect. Notably, the impact of the gas flow rate on these changes is more pronounced than that of the liquid flow rate.