Towards quantitative prediction of aerosol deposition from turbulent flows

摘要

Predictions of aerosol deposition rates from turbulent flow using computational fluid dynamics simulations have been compared with experimental data. The influence of turbulence model choice has been assessed. The use of isotropic turbulence models resulted in over-prediction of V_+ by more than 3 orders of magnitude for τ_+ ～ 0.2, whilst the anisotropic RSM gave results in good agreement with experiment. For τ_+ > 10 (d_p ～ 10 μm for Re = 9894) there was little difference between the turbulence models. Simulations for both Re = 9894 and 50,000 were carried out and good performance was seen for both. The effect of drag model was assessed and resulted in little difference in predicted deposition velocity. The influence of grid resolution was also investigated and it was seen that the cell centre of the wall-adjacent cell should be at a distance of y_+ = 2 or less for quantitative prediction of deposition. Coarser grids resulted in over-prediction for low τ_+.