Gas–Liquid Transport in a Stirred Non-Newtonian Slurry with Co-Rotating and Counter-Rotating Dual-Layer Inclined-Blade Impellers Under Bottom Vibration

Non-Newtonian yield-stress slurries in the presence of entrained gas is a core operation in chemical, mineral-processing, pharmaceutical, and functional-material manufacturing. In such systems, non-Newtonian rheology, gas–liquid interface deformation, vortex evolution, and turbulent dissipation jointly determine the macroscopic flow uniformity. To investigate the effects of impeller configuration and bottom vibration, this study establishes a gas–liquid computational framework that combines the generalized multi-relaxation-time lattice Boltzmann method, a phase-field interface-capturing model, the immersed-boundary method, and the wall-adapting local eddy-viscosity model. The slurry is represented as an effective Herschel–Bulkley continuum; no separate Lagrangian particle phase is included. Co-rotating and counter-rotating dual-layer inclined-blade impellers are compared, and high-frequency bottom vibration is examined as a supplementary momentum-control mechanism. The co-rotating configuration primarily induces circumferential follow-flow and central vortex formation, while low-shear regions persist near the shaft and vessel bottom. Counter-rotation strengthens the interlayer velocity gradient, promotes vortex breakdown, disrupts high-viscosity regions, and opens low-viscosity transport channels; the 45° configuration provides the best balance between radial shear continuity and axial transport. Bottom vibration increases near-bottom shear stress and turbulence intensity, with the 30° configuration showing the strongest coupling. These results establish a quantitative relationship between interlayer momentum exchange and near-bottom momentum compensation and provide a numerical basis for reducing stagnant regions during the mixing of concentrated non-Newtonian slurries.