Cohesive particles arch in eccentric silos

This study investigates the flow behavior of non-cohesive and cohesive particles in eccentric silos using the Eulerian finite element method. The numerical model was rigorously validated against established experimental data. The effects of outlet eccentricity—concentric (e = 0), intermediate (e = 0.5), and extreme (e = 0.84)—as well as silo scale-up were systematically analyzed in relation to particle flow behavior and mechanical response. The results show that outlet eccentricity has contrasting effects on the granular flow behavior in silos for both non-cohesive and cohesive particles. While non-cohesive particles achieve the highest discharge rates in silos with extreme eccentricity, cohesive particles exhibit the lowest critical cohesion coefficients under the same condition. Wall effects are more pronounced for cohesive particles than for non-cohesive ones and become attenuated under silo scale-up—particularly with Type B scaling—resulting in higher critical cohesion coefficients. Trends in the critical cohesion coefficient remain consistent across all configurations: the coefficient increases with particle fill height before stabilizing. This behavior reflects the competing effects of increasing fill height, namely, increased bottom loading vs enhanced sidewall support. The influence of silo width (i.e., scale) on the critical cohesion coefficient becomes significant only at fill heights exceeding 75d_s. These findings underscore the coupled impact of outlet eccentricity, scaling strategy, and fill height on governing arching behavior and flow efficiency. The insights provide actionable guidance for industrial silo design aimed at minimizing flow obstructions and optimizing discharge performance.