Development and Validation of a Binary Collision Detection Algorithm for a Polydispersed Particle Mixture

A time driven Lagrangian particle detection algorithm for a poly-dispersed mixture of particles is developed and validated. The advantage of this algorithm is the possibility to treat a distribution of particle diameters. We are especially interested in the collision treatment of poly-dispersed particle mixtures and coalescence. Particle pairs are found by applying the overlap criteria and additionally another second criterion, which allows a substantial increase of the time step without limiting the algorithm’s accuracy. The algorithm, which is developed here, is validated with test cases by comparison with predictions of the kinetic theory of rarefied gases. They are applied to dry granular flows. The algorithm accuracy is determined with respect to time step criteria, for both dilute and dense systems.