Prediction of particle deposition in turbulent indoor flows with a 3D Lagrangian model

This study describes the development of a three dimensional (3D) Lagrangian code of particle transport in indoor turbulent flows. This approach consists of integrating transport equations for each particle at each time step to determine successive positions of the particle. The first challenge was to calculate instantaneous velocities of the airflow. The mean component of these velocities was calculated by a classic CFD code. A stochastic process based on the Gosman and Ioannides method generated the fluctuating component. Corrections were applied to better fit experimental results. The second challenge was the determination of the wall-particle interactions. These interactions were evaluated through the simulation of small-scale experiments to measure particles deposition on real textures encountered in building surfaces. Two kinds of boundary conditions were tested: a particle rebound probability and a critical velocity of rebound. The latter seems more appropriate for simulating the interaction between textures and 5.0 mm particles.