Hydrodynamic properties of bubbles of different scales in a gas–liquid–solid system

Understanding the properties of bubbles and their impact on flow dynamics is essential in systems involving gas, liquid, and solid phases. This research introduces a groundbreaking theoretical analysis of the hydrodynamic behaviors and interactions of bubbles across different scales. By combining hydrodynamic experiments with computational fluid dynamics modeling, we thoroughly examined the characteristics of bubbles and their interactions with flow fields for three specific bubble sizes (20 μm, 200 μm, and 2 mm) utilizing advanced techniques, such as a high-resolution microscopic imaging, particle image velocimetry, and a coupled volume of fluid and discrete phase model approach. The outcomes of the simulations were found to align closely with the experimental observations. The results indicate that as the bubble rise velocity increases from 0.000 57 m/s for 20 μm bubbles to 0.22 m/s for 2 mm bubbles, the bubble residence time decreases from 219.109 s for 20 μm bubbles to 0.376 s for 2 mm bubbles. Concurrently, the internal bubble pressure decreases from 13 380 Pa for 20 μm bubbles to 986.3 Pa for 2 mm bubbles, and the specific surface area reduces from 92 662.79 m2/kg for 20 μm bubbles to 1183.74 m2/kg for 2 mm bubbles. Moreover, larger bubbles exert a broader influence on the adjacent flow field. The generated vortices transition from small, scattered eddies to larger, symmetrically structured vortices. Additionally, there is an increase in the number of particles being entrained, along with a broader impact of the flow field on particle behavior. These insights offer valuable theoretical support for the design and enhancement of gas–liquid–solid systems in various industrial contexts.