The study reported here has been the modelling of diffusion and convective flow in homogeneous media in which mainly impermeable obstacles have been imbedded randomly. In addition, the dipole flows in interconnected fissures have been investigated as a model for migrations in fissured rock. The results are compared with calculations for pure homogeneous media. Only a few quantitative estimates of uncertainties have been obtained but the visualization of the flow patterns obtained gives an insight into the complexity of the problem. It is demonstrated that pure convective flows around obstacles give rise to dispersion effects as pronounced tailing. The tailing looks similar to that expected in flows in media with dead-pores, matrix diffusion and slow adsorption kinetics and it will no doubt not be possible to identify which of these processes is responsible for a concentration distribution in the outflow from a field experiment. The experimental data obtained by taking samples in the field may not a priori correspond to those modelled, therefore a direct comparison between experiment and theory should be made with some hesitation. It has been shown that in principle only three-dimensional modelling will be able to predict the complicated non-symmetric flows around obstacles.
Bibliographic Reference: EUR 16765 EN (1996) 49pp., FS, ECU 7.00
Availability: Available from the (2)
ISBN: ISBN 92-827-6187-8
Record Number: 199610361 / Last updated on: 1996-04-15
Original language: en
Available languages: en