Multi-Bubble Transient Dynamics under Inclined Carbon Anodes Using an Air–Water Model of the Hall–Héroult Electrolytic Cell

We developed a novel one-fifth-scale, low-temperature air–water model of the Hall–Héroult cell that preserves geometric, kinematic, and dynamic similarity with industrial conditions. High-speed imaging captured key bubble dynamics under varying anode inclinations (0–6°) beneath a scaled prebaked carbon anode, revealing that increased inclination enhances buoyancy, reduces bubble size and thickness, limits coalescence, and accelerates detachment. Streamline analysis shows consistent bubble release from the downstream corner, with the velocity increasing near the release zone. Vorticity fields indicate stronger vortices at anode edges, while shear and strain rates reveal greater velocity gradient variations, promoting longitudinal acceleration. Statistical analysis highlights transitions in bubble growth distributions and confirms buoyancy-driven detachment. Increasing the inclination significantly reduces bubble coverage, resistance, and residence time, with the most pronounced effect at 1°. Finally, transient velocity analysis shows peak velocities at the release area and lowest at the generation site, with inclined anodes enhancing turbulence and horizontal anodes exhibiting random velocity fluctuations.