Granular flow provides a Lagrangian description of a problem by solving ordinary differential equations using Newton’s law of motion. Granular flow implements the discrete element method (DEM), which is a particle-based method that takes into account the translational and rotational degrees of freedom of the particles, which are referred to as grains in granular flow. DEM tracks the motion of individual grains by taking into account the forces on the grains due to external fields such as gravity and contact with other grains and walls to predict the bulk motion.