Eulerian-Eulerian-Lagrangian Simulation of Fuel Mixing in Fluidized beds

In this paper, we combine Eulerian-Lagrangian and Eulerian-Eulerian frameworks to track a limited number of fuel particles in a bulk of inert particles in a gas-solid fluidized bed. The gas and the inert phase are treated as interpenetrating continua and resolved within the Eulerian-Eulerian framework, whereas the fuel particles are regarded as a discrete phase. In the method, the forces acting on a fuel particle are calculated by using the velocity and pressure fields of the mixture of the inert solid particles and gas.. To validate the numerical method, the results are compared with experimental data in the form of preferential positions, velocity vectors and dispersion coefficient of the fuel particles. The effects of a number of operating parameters (e.g. the fluidization velocity and the amount of bed material) on the mentioned properties of the fuel particles are studied. In addition, to accurately formulate the inlet boundary condition the air supply system is included in the computational domain. It is observed that the proposed numerical technique is able to correctly capture the behaviour of fuel particles in fluidized beds.