Bare galvanized steel and internally insulated bends
Orientation
Horizontal to downwards vertical
NRd
Horizontal to horizontal and horizontal to vertical
Upwards vertical to horizontal and horizontal to downwards vertical
Construction technique
NRd
NRd
Smooth, gored, and segmented
NRd
Hydraulic diameter, (cm)
0.501 and 0.851
1.6
15.2 and 20.3
15.2
Curvature ratio, (–)
5.7
1–20
1.7–12
3.01
Bend angle, (deg)
90
45–135
45, 90, 180
90
Air flow
Reynolds numberb1, (×103)
6 and 10
3.2–19.8
203 and 368
21.6–88.3
Bulk velocity, (m·s−1)
18 and 31
7.7 and 18.6
20 and 27.1
2.2, 5.3, and 9.0 (8.8)
Particles
Aerosol type and material (density) (g/cm3)
Monodisperse liquid oleic acid (0.89)
Monodisperse liquid oleic acid (0.89)
Polydisperse glass spheres (2.45)
Monodisperse fluorescent particles (1.15)
Diameter, (μm)
1.1–6.6
10
5–150
1–16
Stokes number, (–)
0.03–1.35
0.07–0.7
0.08–16
0.00013–0.081
Reynolds numberb2, (–)
1.3–12.7
0.05–1.5
10–200
NRd
Dimensionless relaxation time, (–)
0.4–27
0.4–23
NRd
0.0046–12
Comments
Assumption of no particle rebounding
Assumption of no particle rebounding
No particle rebounding using petroleum jelly
System method to reduce the effect of particle rebounding
aOnly experimental data [15]; b1Reynolds number: ;b2particle Reynolds number: ;cbend 6 in [20] is not included, and bend 5 is the downstream half of a 180° quasi-bend; dNR: not reported.