Numerical simulations of ultrafine powder coating systems

In numerical simulations, the air flow field is obtained by solving three-dimensional Navier-Stokes equations with standard κ-ɛ turbulence model and non-equilibrium wall function. The second phase, the coating powder, consists of spherical particles and is dispersed in the continuous phase, the air. In addition to solving transport equations for the air, the trajectories of the particles are calculated by solving the particle motion equations using Lagrangian method. It is assumed that the particle-particle interaction can be neglected due to low particle volume fraction in coating systems. The electrostatic field is predicted by solving the Laplace equation.