An extension of hard-particle model for three-dimensional non-spherical particles: Mathematical formulation and validation

Particle collision model plays an important role in Eulerian-Lagrangian simulation of particle-fluid flows. A new theoretical three-dimensional collision model for generalized non-spherical rigid particles is proposed by using an improved and generalized definition of the coefficient of restitution for general shape particles and following the fundamental laws of momentum, energy and friction. Moreover, the consistence between the present model and the existing hard sphere model under simplified conditions has been demonstrated by reducing the general solution to the special solution for spheres. This model is also validated by a numerical test of collision process between cubic particles using conservation laws and an experiment of collision between a brick particle and a flat surface. The validation work indicates the feasibility of this model to be used for general non-spherical particle-fluid flows. In addition, a particle discharging flow in a lifting hopper is simulated with satisfactory agreement with experimental results, which shows the successful demonstrative application of current model for complex particle flow simulation.