Flow kinematics of granular materials considering realistic morphology

• Published in: Powder technology 2023-06, Vol.424, p.118516, Article 118516
• Main Authors: Kalyan, NSSP, Kandasami, Ramesh Kannan
• Format: Article
• Language: English
• Subjects: Coarse graining; Flow kinematics; Granular flow; K-means clustering; Non-convex morphology
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2023.118516

The study focuses on understanding the influence of particle morphology, interparticle friction and hopper exit width on spatial and temporal variations in velocity during dry granular flow. Using non-convex morphologies (sand, chickpea and rice), the flow characteristics and velocity fluctuations are explored. Funnel flow pattern was evident in angular shapes even in hoppers designed for mass flow discharge. K-means clustering, an unsupervised algorithm, is used to group the spatial variation of velocity inside the hopper. Three flow clusters were identified which indicate the flow transition from funnel to mass flow. The Free Flow Cluster (FFC) height was observed to be least for bulky-shaped particles because of their high sphericity and roundness values. Angular particles were observed to exhibit rapid temporal velocity fluctuations when compared to elongated and bulky shapes. Finally, the pseudo-shape approximations typically used in DEM fail to capture the true interlocking nature in the flow behaviour observed within realistic particle morphologies. [Display omitted] •Realistic non-convex polygons are used in hopper flow simulations.•Funnel flow pattern is dominant in angular particles compared to elongated and bulky.•Particle orientation influences the spatial variation of velocity.•K-means clustering reveals semi-circular flow zone near the hopper exit.•Temporal velocity fluctuations are rapid in angular particle morphologies.