• • Model validation: CFD predictions of particle concentration distribution deviated by only 6.4% from experiments, and mainstream solid-phase velocity errors averaged 3.3%, confirming high fidelity for engineering design.
• • Concentration effect: Ice slurry at 60% initial concentration achieved an effective shear stress ratio of 77.39%, enabling thorough cleaning of both upper and lower pipe walls; at 20% concentration, no effective shear occurred at the pipe bottom, with an overall ratio of 42.18%.
• • Velocity dominance: Flow velocity is the most influential parameter; increasing from 0.2 to 1.0 m/s raised the effective shear stress ratio from negligible to 83.16%, with cumulative shear stress increasing and becoming more uniform.
• • Optimal parameters: The combination of 50% initial concentration, 0.5 mm particle diameter, and 1.0 m/s flow velocity yielded an average cumulative shear stress of 11.59 Pa·s and an effective cumulative shear stress of 9.89 Pa·s, representing the best cleaning performance.