Wetting effects on the dynamics of droplets and bubbles at surfaces

Abstract

Dynamic wetting plays a fundamental role in the dynamics of droplets and bubbles at solid surfaces by influencing contact line motion and interfacial evolution. In this work, three representative wetting-controlled benchmarks, namely droplet splashing, bubble coalescence at solid surfaces, and bubble dynamics under shear flow, are investigated using a three-dimensional volume-of-fluid framework coupled with a recently developed dynamic wetting model based on contact line velocity reconstruction method [19]. The model is first validated against experimental observations and literature data for droplet splashing and bubble coalescence. It accurately reproduces the transient contact line evolution, splashing morphology, and coalescence dynamics. In particular, dynamic wetting suppresses the premature bubble detachment predicted by static wetting models and yields substantially improved agreement with experimental observations. In shear flow, contact angle hysteresis and contact line dissipation strongly influence bubble deformation, sliding, and detachment. These results demonstrate that accurate treatment of dynamic wetting is essential for predicting wetting-controlled droplets and bubbles involving rapid contact line motion, strong interfacial deformation, and topology changes.