Influence of the wettability nature of the nozzle wall on the dynamics of drop formation

Abstract

This paper describes the Volume of Fluid model in which a driving force is applied to stimulate the droplet ejection. Through this model, the wettability of the nozzle’s inner wall will be determined as it plays a vital role in the droplet’s shape and size. The effect of parameters viz. breakup thread length, breakup velocity, breakup/ detachment time on the drop formation are computed in this paper by using volume of fluid method. The results indicate that the increase in contact angle of the nozzle inner wall reduces the drop’s breakup time while increasing the breakup velocity and thread length of the drop. Also, the results indicate the reduction in quality of drop formation with increased hydrophobic nature, which is not suitable for spray painting or in inkjet printing. Similarly, the deterioration in the quality of drop formation is due the more hydrophilic nature of the nozzle.