Research on continuous and instantaneous heavy gas clouds
report
This report describes the contribution of MT-TNO to the joint CEC pro ject 'Research on continuous and instantaneous heavy gas clouds'. The aim of this CEC project is to provide enhanced numerical and/or physical methods to predict the behaviour of heavy gases released in the atmosphere. The dispersion of heavy gases over flat terrain in terms of time-averaged concentration is quite well understood. This project was focussed on the effect of obstacles on the dispersion and on concen tration fluctuations: - In practical situations obstacles in the form of buildings and other installations will be present. These obstacles may significantly influence the dispersion process, but little quantitative guidance can presently be given on the magnitude of the effect on the spatial and temporal distributions of the concentration field. - Until now, models used for predicting atmospheric concentrations of contaminants have been those which produce time or ensemble-averaged values. However, some contaminants are so toxic that harmful effects may occur at short exposure times. For these contaminants, models that provide only expected values of averaged concentrations are inade quate .
Topics
TNO Identifier
252336
Publisher
TNO
Collation
152 p.
Place of publication
Apeldoorn