Measured deposition of aerosol particles on a two-dimensional ribbed surface in a turbulent duct flow

Neutron activatable tracer-labelled particles were used to study the aerosol deposition for both smooth and ribbed surfaces of a duct under turbulent flow conditions. Spatial distribution of aerosol deposition along the horizontal upward-facing ribbed surface was experimentally determined. For four particle sizes in the range 0.7–7.1 μm, pronounced aerosol deposition was observed on the frontal and top surfaces of the ribs, and particle deposition enhancement, on the ribbed surfaces relative to a smooth surface, as high as seven times was observed. The presence of repeated square ribs on the duct surface caused a pressure increment of 3.2, relative to a smooth duct. Efficiency ratios (pressure drop-weighted aerosol deposition enhancement) greater than unity were evaluated for the four particle sizes studied.