Influence of breakup regimes on the droplet size produced by splash-plate nozzles

An experimental study was conducted to identify the influence of the breakup regime on the droplet sizes produced by a splash-plate nozzle. Sprays formed by splash-plate atomizers were categorized according to the different types of breakup regimes of a spreading liquid sheet. Mean droplet sizes of various splash-plate nozzles were determined and they were correlated to liquid viscosity, nozzle diameter, and flow velocity. Various mixtures of corn syrup and water were used to obtain viscosities in the range of 1-140 mPa x s. Three different splash-plate nozzles of 0.5, 1, and 2 mm with a constant plate angle of 55 deg were tested. A phase Doppler particle analyzer was used to determine the droplet sizes generated at various operating conditions. The results indicated that the droplet-size correlations for a splash. plate atomizer depend on the liquid-sheet breakup regime. The effect of viscosity based on power-law correlation was changed by about 2 orders of magnitudes in the exponent when the breakup regime changed from the Rayleigh-Taylor instability regime with stable rim to the sheet perforation regime.