Diffusion from a fixed source at a height of a few hundred feet in the atmosphere
- 1 January 1957
- journal article
- research article
- Published by Cambridge University Press (CUP) in Journal of Fluid Mechanics
- Vol. 2 (3), 299-310
- https://doi.org/10.1017/s0022112057000142
Abstract
The results of measurements of the vertical distribution of airborne particles, released usually at a height of 500 ft., and sampled for periods of about 30 minutes at downwind distances of 100, 300 and 500 metres, are presented and discussed.At all distances the frequency distributions of the particle elevation with respect to the site of release are closely similar in shape and size to the frequency distribution of wind inclination at the site of release. This is interpreted as showing that, despite the uncorrelated effects of small eddies, high correlation was maintained in the motion of a particle, for periods of 1 minute or more, by the dominant action of persistent eddies which contributed heavily to the turbulent energy. In contrast to this result, the wind observations showed that the Eulerian auto-correlation coefficient (Rr) fell to about 0.2 in 10 seconds.Keywords
This publication has 3 references indexed in Scilit:
- DEPOSITION OF AIR‐BORNE LYCOPODIUM SPORES ON CYLINDERSAnnals of Applied Biology, 1951
- Wind structure and evaporation in a turbulent atmosphereProceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, 1934
- A theory of eddy diffusion in the atmosphereProceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, 1932