External characteristics of spray atomisation from a nasal spray device

Atomisation of liquids is a complicated process. It is common in many industries such as automotive, manufacturing (spray drying) and mineral processing. These industries often use high-pressure spray devices and its studies are common in the literature. However, in the pharmaceutical industry atomisation occurs under low pressure and studies in the literature are not as common. Spray formation was simulated in Ansys CFX under a Lagrangian model. The primary breakup Blob model is used to handle atomisation of the liquid while the secondary breakup TAB and ETAB models are evaluated for the subsequent breakup of the atomised droplets.Two-way coupling was applied in order to simulate the interaction between initial ambient gas and the liquid droplets. It was found that the spray half cone angle was unexpectedly large at early spray development in the simulation, but the calculated results matched better with the experimental results in the later stages of spray development. The study also demonstrated that the ETAB model had a better prediction of axial penetration and radial range in the 6 bar high pressure injection case over the TAB model. However the TAB model did perform better under a lower injection pressure case