Experimental Investigation on Liquid Breakup and Injection Characteristics of a Rotary Slinger Atomizer

An experimental study was conducted to investigate the liquid breakup characteristics of rotary slinger atomizers. The experimental test rig equipped with a high-speed spindle motor was constructed to observe the external flow of the rotary slinger atomizer. The behavior of water injected from the orifices was visualized using a high-speed camera. The breakup characteristics for different rotational speeds and mass flow rates were compared between two different atomizers with four and eight orifices. To evaluate the atomization performance quantitatively, the aerodynamic Weber number, the liquid-gas momentum flux ratio and the Coriolis bond number were selected as dimensionless numbers. The regime maps of the breakup characteristics consisting of dimensionless numbers were obtained by applying two different classifications: the liquid primary breakup mode and the liquid injection mode. The liquid column trajectories and the liquid breakup lengths were obtained by an image processing sequence and were formulated as empirical correlations.