Simulation of particle mixing in turbulent channel flow due to intrinsic fluid velocity fluctuation

We combine a DEM simulation with a stochastic process to model the movement of spherical particles in a turbulent channel flow. With this model we investigate the mixing properties of two species of particles flowing through the channel. We find a linear increase of the mixing zone with the length of the pipe. Flows at different Reynolds number are studied. Below a critical Reynolds number at the Taylor microscale of around $R_{c} \approx 300$ the mixing rate is strongly dependent on the Reynolds number. Above $R_{c}$ the mixing rate stays nearly constant.