Spray characteristics of a compound rotary pressure atomization nozzle

Abstract This study investigates the effects of compound rotary pressure swirl atomization on spray characteristics. Experiments utilized high‐speed videography and laser particle size analysis to characterize the spray mechanism and elucidate how operational parameters influence the Sauter mean diameter ( d 32 ) and droplet size distribution (DSD), respectively. Based on the experimental findings, predictive models for d 32 and DSD were subsequently developed. When the pressure‐swirl nozzle rotates, the liquid becomes simultaneously subjected to Coriolis forces, centrifugal acceleration, and aerodynamic forces. This accelerates liquid film breakup—first into sheets, then into droplets. Higher rotation speeds were found to reduce the d 32 and narrow the DSD. Prediction models for d 32 and DSD were developed using distinct methodologies. The d 32 model, derived through dimensionless analysis, achieves high accuracy with errors consistently below 10%. The DSD model, based on the modified Rosin–Rammler (R–R) distribution, demonstrates improved precision with errors under 15%. These findings offer valuable insights for the rational design and optimization of spray‐related processes.