Experimental and computational study of liquid drop over flat and spherical surfaces

Abstract

Flow of a liquid droplet over a flat plate and a spherical pellet was studied to improve understanding of wetting in trickle bed reactors. High speed imaging system and computational fluid dynamics (CFD) was used for this purpose. Experimental data is reported on dynamics of drop rest on a flat and a spherical surface. Micro-scale motion of liquid droplet on these surfaces was captured with a high-speed CCD camera. Images were analyzed to provide quantitative data of drop dynamics. Drop spread and recoiling velocities were reconstructed from the experimental data. CFD model based on the volume of fluid (VOF) method was used to simulate drop dynamics on flat and spherical surfaces. Surface tension and wall adhesion phenomenon were included in the computational model. Simulated drop dynamics was found to capture key qualitative features observed in the experiments. Numerical simulations with three-dimensional domains are essential for quantitative comparison with experimental data. The experimental results and computational model discussed in this paper would be useful for better understanding of wetting in trickle bed reactors.