| Investigators | Wilson et al. [21] | Ghaffarpasand et al. [24] | Sun et al. [22, 23] | Lin et al. [10] |
| Duct bends | | | | | Bend type | Small tube | Small tube | Indoor rectangular ventilation duct | Small tube | Deposition surface material | Standard stainless steel (grade 304) | Stainless steel, hydraulically smooth | Galvanized steel and acrylic glass | Plexiglass | Orientation | Downwards vertical to horizontal | NRd | Horizontal to horizontal | NRd | Construction technique | Made by a standard tube bender | NRd | Made by university industrial center | NRd | Hydraulic diameter, (cm) | 1.02 | 0.48 | 10 | 1.2 | Curvature ratio, (–) | 7.4 | 13.25–54 | 3.4 | NRd | Bend angle, (deg) | 90 | 90 | 90 | NRd |
| Airflow | | | | | Reynolds number, (×103) | 10.25, 20.5, and 30.75 | 4.5–10.5 De = 1426–2885e | 17.9, 35.6 | De = 370–950e | Bulk velocity, (m·s−1) | 15.4, 30.8, and 46.2 | NRd | 2.58, 5.14 | NRd |
| Particles | | | | | Aerosol type and material (density) (g/cm3) | Vitamin E, that is, alpha-tocopheryl acetate (0.91) | Tungsten oxide (10.8) and ammonium nitrate (1.725) | Arizona standard test particle, basically SiO2, and Al2O3 (2.65) | Polydisperse particles with vegetable oil | Diameter, (μm) | 2.2–11 | 0.001–0.02 (monodisperse) | 0.7–100 (polydisperse) | 0.008–0.55 | Stokes number, (–) | 0.12–1.08 | 0.001–0.03 | 5.2 × 10−4–0.55 | NRd | Reynolds numberb2, (–) | NRd | NRd | NRd | NRd | Dimensionless relaxation time, (-) | NRd | Sc = 15–820f | 0.34–27.6 | Sc = 186–268,819f |
| Comments | Assumption of no particle rebounding | Nanoparticle, neglected coagulation | With particle-wall collision | Nanoparticle mechanism considered |
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