Aerosol deposition in bifurcating ducts with curved inlet

Abstract

The quantitative knowledge gained from the assessment of particle deposition in ducts is important to study, for example, the elimination of air leakage from duct systems with aerosolized sealant particles or to implement strategies of cleanliness of air ventilation systems. The study of particle deposition on the components of ventilation systems contributes also significantly to a better understanding of human exposure to particulate pollution. In this work we investigate deposition of aerosol particles in bifurcating ducts with a curved inlet segment. An experimental set-up was designed for the study of the influence of the inlet segment characteristics (curvature ratio, bend angles) and bifurcation characteristics on aerosol deposition. These experiments cover aerosol particles with sizes ranging from 2 to 12 micron and airflow rates of 0.41 mm3/s (Re=1950) and 1.7 mm3/s (Re=8050). The results obtained show that the deposition of particles in the duct is significantly enhanced with increasing particle size. In contrast, the effect of Reynolds number upon particle deposition is less important. Accumulation of particles in the bifurcating segment of the duct seems not to be affected by the inlet segment characteristics.