How does an emulsion drop's viscosity influence its impact on various meshes?

Abstract

The impact of emulsion drops on a mesh is studied. These drops find applications in various fields, e.g., agricultural sprays, where the drop passes through a mesh for atomization. Both penetration (full or partial) and lateral spreading are observed in most cases. The maximum spread's variation with Weber number (We) shows liquid independence for drops impacting a given mesh. The variations can be concluded into one. However, when both lateral spread and penetration are concerned, the emulsion drop with the highest water content tested stands out as different. It shows dissimilar characteristics due to its higher viscosity. The drop's lateral spread Reynolds number is lower than the others, indicating a significant dependence on the liquid viscosity. Rising viscosity resists the lateral inertia. Surface tension (ST) and density do not have much influence. The balance between the downward and after-impact lateral inertia and their resistance makes the lateral spread on a given mesh independent of liquid. Three regimes, full, partial, and no penetration, can be defined. A dissimilarity in the after-penetration jet length is detected. The length is inversely proportional to the emulsion's rising water content. The drop with the highest viscosity, together with ST, provides the highest resistance to penetration. Thus, the length reduces abruptly. When the after-impact penetration cone angle is studied, the average angle reduces with We for the highest viscosity emulsions. An abrupt rise in resistance is detected. The study's novelty lies in bringing out the viscosity's influence on the emulsion drop's impact on a mesh.