Particle deposition from turbulent duct flow.

Particle deposition from turbulent duct flow is modelled and related to particle penetration of a ventilation system for a commercial office building. Three published turbulent deposition models capable of accommodating surface roughness are compared to experimental data and used to determine the penetration of 0.1 - 10 (m spherical particles through a sample duct run. Depending on the model employed, penetration fractions varied from 0.40-0.94 for 0.1 (m particles and 0.28-0.73 for 10 (m particles. Penetration is predicted to be independent of particle size for particle diameters less than 2 (m. Almost all the deposition is predicted to occur in short sessions of the duct runs where the wall roughness is larger than in other duct sections because of the duct construction material.