Deposition of particles to canopies in the wind tunnel

Wind tunnels provide a partial solution to the study of deposition of particles in the natural environment. The main advantage is that conditions are reproducible. Also, if radioactive aerosols are used, much less activity is needed than in field experiments. The disadvantages are the limitations on the height of the canopy and on the fetch 

2i2pb 10 3 Generation by decay of 220Rn in dust-free air 212Pb 

Aitken nuclei -0.08 Accumulation of nuclei in laboratory air 212Pb 

Polystyrene spheres 5 Solution of polystyrene in xylene atomised from spinning top 51Cr 

9 refers to a friction velocity of 0.35 m s , corresponding to a wind speed of about 2 m s 1 in the tunnel. Measurements by Moller Schumann (1970) of deposition of radioactive particles in a water/wind tunnel (w = 0.4 m s-1) are also shown. 

---