Model of Particle-Particle Interaction for Saltating Grains in Water

A model of particle-particle interaction for bed sediment-laden flows, based on impulse equations, is presented. The model is applicable to dense flows in which particle motion is dominated by collisions. The model takes into account the possibility of sliding during the collision process. However, particle rotation is not considered in this model. The governing equations do not incorporate dimension of angular momentum. To verify this model, calculation of post-collision velocities was performed for several different collision simulations. The term of particle-particle interaction is implemented into a general Lagrangian model of trajectory of a sediment grain in a fluid flow. This general Lagrangian model is written according to Newton's second law; the rate of change of momentum of a particle is balanced against the surface and body forces.