Bubble characterizations on hydrophobic surface using lattice Boltzmann simulation with large density ratios

Purpose - The maintenance of the air-water interface is crucial for the drag reduction on hydrophobic surfaces. But the air bubbles become unstable and even washed away under high speed flow, causing the failure of surface hydrophobicity. Thereby, this paper aims to understand the relations between bubble behaviors and surface properties, flow conditions and to discover new methods tomaintain the air-water interface. Design/methodology/approach - Bubble properties on hydrophobic surfaces were characterized using single-component multiphase lattice Boltzmann simulation. Three equations of state (EOSs), including the Peng-Robinson, Carnahan-Starling and modified Kaplun-Meshalkin EOSs, were incorporated to achieve high density ratios. Findings - Both the static and dynamic properties of bubbles on hydrophobic surfaces were investigated and analyzed under different flow conditions, solid-liquid interactions and surface topology. Originality/value - By revealing the properties of bubbles on hydrophobic surfaces, the effects of flow conditions and surface properties were characterized. The maintenance method of air-water interface can be proposed according to the bubble properties in the study.