Flow characteristics and discharge rate of ellipsoidal particles in a flat bottom hopper

•Particle shape affects flow patterns and wall stresses significantly.•Ellipsoids flow slower than spheres.•The Beverloo equation is modified based on DEM simulated results.

Hopper flow characteristics are significantly affected by particle shape. In this work, ellipsoidal particles which can represent a large number of shapes are used to investigate the shape effect on granular flow in a cylindrical hopper. Numerical experiments are conducted by use of the discrete element method, with its validity verified by comparison with the results from physical experiments. The results indicate that particle shape can make a significant effect on the flow pattern. In particular, the increase of deviation from spheres can decrease the mixed region adjacent to the side wall, and increase the stagnant zone at the bottom corner. It may also lead to decreased wall stress. Furthermore, particle shape has a significant effect on the discharge rate. Spheres of unity aspect ratio have the highest flow rate, and the lower or higher aspect ratio, the smaller the flow rate. Based on the numerical results, the Beverloo equation is modified, where parameters C and k in the equation are respectively formulated as a function of aspect ratio.

Graphical abstractDEM is used to investigate hopper flow behavior with ellipsoidal particles. Particle shape affects flow patterns and stresses significantly. The Beverloo equation is then modified based on simulated results by formulating parameters C and k as a function of aspect ratio.Figure optionsDownload full-size imageDownload as PowerPoint slide