Theoretical Spray Performance of Swirl-type Nozzles

Theoretical spray performance of swirl-type nozzles was developed by solving boundary flows in the swirl chamber of the nozzle using the integral momentum method. Essential structures of the discharge coefficient, the swath coefficient, and the volume median diameter were derived from the theoretical investigation of fluid motion. The nozzle parameters and average relative velocity at the discharge orifice governed the spray performance and flow regions. Extreme conditions that sensitively influenced the spray performance at high and low flow rates were identified from the theoretical analysis. The theoretical spray performance discussed in this study would be a basic form for the design of a variable flow swirl nozzle, and be subject to calibration for a specific configuration of the swirl nozzle.