Mesoscopic Analysis of Droplet Spreading Behaviour on Wetted Surface for Low Viscosity Ratio

Abstract

In the present study, the interfacial dynamics of displacement of three dimensional spherical droplet on a rectangular microchannel wall considering wetting effects are studied. The two-phase lattice Boltzmann Shan-Chen model is used to explore the physics. The main focus of this study is to analyse the effect of wettability, low viscosity ratio and capillary number on the displacement of spherical droplet subjected to gravitational force. The hydrophobic and hydrophilic nature of wettabilities on wall surface are considered to study with capillary number, Ca=0.1, 0.35 and 0.66 and viscosity ratio, M ≤ 1. The results are presented in the form of temporal evolution of wetted length and wetted area for combined viscosity ratios and wettability scenario. In the present study, it is observed that in dynamic droplet displacement, the viscosity ratio and capillary number play a significant role. It is found that as viscosity ratio increases, both the wetted area and the wetted length increase and decrease in the case of hydrophilic and hydrophobic wettable wall respectively.