An artificial smoke particle increases rapidly with particle size. The settling velocity is proportional to the square of the particles diameter.
Particle diameter (µm)
Setting Velocity(m/s)
Setting Velocity(mm/hr)
0.05
3.85E-07
1.39
0.06
4.75E-07
1.71
0.08
6.69E-07
2.41
0.1
8.82E-07
3.18
0.15
1.50E-06
5.40
0.2
2.26E-06
8.14
Typical Concept particle
0.3
4.21E-06
15.16
0.4
6.76E-06
24.34
0.5
9.91E-06
35.68
0.6
1.37E-05
49.32
0.8
2.30E-05
82.80
1
3.48E-05
125.28
1.5
7.47E-05
268.92
2
1.30E-04
468.00
3
2.85E-04
1026.00
Typical cast h/e
4
5.00E-04
1800.00
distribution
5
7.76E-04
2793.60
6
1.11E-03
3996.00
8
1.96E-03
7056.00
10
3.06E-03
11016.00
15
6.84E-03
24624.00
20
1.21E-02
43560.00
30
2.72E-02
97920.00
The terminal settling velocity of an aerosol or "artificial smoke" particle increases rapidly with particle size. The settling velocity is proportional to the square of the particle diameter, although sub micron particles, such as those produced by Concept systems require the use of slip correction factors.
Calculated for standard density spheres at 293 K [20° C] and 101 kPa (1 atm).
"Aerosol Technology", William C. Hinds, Wiley-Interscience, 1999