Numerical study for the impact of liquid droplets on solid surfaces

Abstract

The impinging behaviour of liquid droplets on solid surfaces is studied using a computational approach. The analysis comprises the unsteady three-dimensional conservation equations of mass and momentum, with the surface tension effect treated by the continuous surface force model. Gas-liquid interfacial motions are simulated by the volume-of-fluid method in conjunction with the piecewise linear interface construction technique. In the computer code validation for a water droplet impacting on a polished stainless steel surface, computer-generated images of the time evolution of the droplet impingement dispersal shape are compared with magnified photographs by Pasandideh-Fard et al. The flow and transport phenomena in the impingement flowfield are further examined in detail. In order to respond to the need for its use in practical applications, the study is extended to explore the spreading progression to achieve a better understanding of the interaction of a 30 μm diameter polyethylenedioxy thiophene liquid droplet with a 50 × 50 μm indium tin oxide-coating square cavity at an impact velocity of 6 m/s.

Droplet Misalignment Limit for Inkjet Printing into Cavities on Textured Surfaces

“…Experiments with droplets of different Weber numbers were investigated for rectangular slots by Subramani et al 12 , where two splashing regimes were identified: one internal splash similar to impacts on planar surfaces and the other where the cavity structure causes a splash to extend outside of the cavity. Deposition into square cavities was investigated using a volume of fluid method by Yang et al 13 , including off-centre deposition, and it was found that the cavity did not fully fill for an off-centre deviation of 10 . Experiments and computational fluid dynamics (CFD) simulations of droplet deposition into cavities were performed by Liou et al 14 , where Weber number and cavity wall wettabilities were studied to find optimum wetting conditions.…”

Droplets Atop a Wrinkled Substrate

“…It leads to numerous applications in industry, such as printing and soldering [1][2][3]. Usually, it is studied by taking a liquid droplet atop a solid surface as an object [4], and the variables are related by Young equation (1) (Fig. 1).…”