COMPUTER-SIMULATION OF DEPOSITION OF AEROSOLS IN A TURBULENT CHANNEL FLOW WITH ROUGH WALLS

Dispersion and deposition of particles in a turbulent channel flow with rough walls are studied. A procedure for simulating the deposition of aerosol particles on a rough surface is developed. The instantaneous turbulent flow field is generated as the sum of a mean and a randomly fluctuating Gaussian field. Particle equation of motion including the effects of Brownian diffusion, Saffman lift force, and gravity is solved numerically. Starting with an initially uniform concentration near the wall, ensembles of particle trajectories are generated and statistically analyzed. Several simulations for deposition of aerosol particles of various sizes are performed and the corresponding deposition velocities are evaluated. The results are compared with those obtained by empirical equations and experimental data.