Numerical simulation of the dynamics of a bubble lying between a free particle and a solid horizontal surface: spreading and detachment

• The spreading and detachment behavior of bubble between particle and wall was simulated. • Bubble detachment is driven by surface wave generated upon contact with particle. • Particle size significantly affects the absolute quantity of bubble energy. • Energy conversion efficiency increases after bubble contact hydrophobic particle. When particles are present in the boiling heat transfer process, they interact with bubbles, thereby influencing the dynamic behavior of the bubbles. This paper presents a 2D planar simulation study of the detachment behavior of a bubble adhering to a solid horizontal surface after contact with a particle using the IBM-VOSET-DEM method. The effects of particle wettability θ p (=30–150°), radius ratio between particle and bubble k r (=0.3–1.4), and the density ratio k ρ (=2.09–9.31) between the particle and the liquid phase on the spreading-retraction behavior and energy conversion during bubble-particle contact were investigated. Results demonstrate that surface waves form upon bubble-particle contact, driving the bubble through a dynamic process of retraction-spreading-retraction-detachment on the surface. The scaling laws were established between dimensionless spreading angle β , bubble height k h , secondary retraction contact length k α , and dimensionless time t for various particle wettabilities and sizes. Particle wettability exerts the most significant influence on bubble dynamics, followed by particle size, while particle density has a lesser effect. Detachment behavior is primarily determined by kinetic energy converted from surface energy during the first stage, with secondary surface energy release having minor effects. As the contact angle θ p of the particle increases, the energy conversion efficiencies η sk (from surface energy E s to kinetic energy E k ) and η kd (from kinetic energy E k to detachment kinetic energy E d ) exhibit an exponential increasing trend. The size ratio k r significantly affects the absolute quantities of energy, but its impact on conversion efficiencies η sk and η kd is comparatively minimal, remaining within ranges of 0.026 % to 0.030 % and 25.16 % to 30.00 %, respectively.