The exponential probability density function and concentration fluctuations in smoke plumes
β Scribed by Steven R. Hanna
- Publisher
- Springer
- Year
- 1984
- Tongue
- English
- Weight
- 719 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0006-8314
No coin nor oath required. For personal study only.
β¦ Synopsis
Observations of l-s average concentration fluctuations during two trials of a U.S. Army diffusion experiment are presented and compared with model predictions based on an exponential probability density function (pdf). The source is near the surface and concentration monitors are on lines about 30 to 100 m downwind of the source. The observed ratio of the standard deviation to the mean of the concentration fluctuations is about 1.3 on the mean plume axis and 4 to 5 on the mean plume edges. Plume intermittency (fraction of non-zero readings) is about 50% on the mean plume axis and 10% on the mean plume edges. A meandering plume model is combined with an exponential pdf assumption to produce predictions of the intermittency and the standard deviation of the concentration fluctuations that are within 20% of the observations.
π SIMILAR VOLUMES
The time evolution of dynamical systems with random initial conditions is considered, by deriving the n th order probability density of the stochastic process which describes the response of the system, and the entropy function related to the said distibution. A constructive theorem is proved, which