Maximum spreading of liquid droplets impact on concentric ring-textured surfaces: Theoretical analysis and numerical simulation

Abstract

It is fundamentally significant to predict the maximum spreading of liquid droplets impact on textured surfaces. However, relevant work is very limited. Considering the effects of contact line pinning and liquid penetration into textures, a theoretical model to predict the maximum spreading factor on concentric ring-textured surfaces is developed. Validated with numerical simulations conducted by an effective, sharp-interface, continuum level modeling method, this model has shown a good predicting performance. It is demonstrated that in the viscous regime, the viscous dissipation arising from liquid penetration into textures has a considerable effect on the maximum spreading factor, whereas the effects of the contact line pinning and surface energy are negligible. Meanwhile, as viscous dissipation becomes more dominant, the effect of texture gap on maximum spreading is less visible. The phase diagram of the wetting state at maximum spreading is also provided. We indicate that the intermediate wetting state is favorable under small Reynolds number and narrow texture gap, while the partial wetting state is supported under the opposite conditions.