DIRECT SIMULATION OF CHARGED-PARTICLE DEPOSITION IN A TURBULENT-FLOW

Wall deposition of charged particles in a turbulent duct flow in the p resence of electrostatic charges is studied. The turbulent flow veloci ty field is generated by a direct numerical simulation of the Navier-S tokes equation via a pseudospectral method. It is assumed that the par ticles are sufficiently small and widely separated that they do not in teract and have no influence on the fluid motion. The equation of moti on of particles including the Brownian and electrostatic forces is use d in the analysis. Ensembles of 8192 charged particle trajectories are evaluated and statistically analyzed. Uniform and Boltzmann charge di stributions on the particles are considered. Effects of size and elect ric field intensity on particle dispersion and wall deposition rate ar e studied. The results are compared with those obtained from empirical equations. (C) 1997 Elsevier Science Ltd.