Numerical modelling of two-phase flow in a geocentrifuge

In this paper, results of DNAPL spreading experiments carried out in a geocentrifuge are analysed. The experiments are performed in the GeoDelft geocentrifuge. The experiments investigate the intrusion of a known amount of PCE into a water-saturated soil sample. They are carried out under 12, 15, and 30g conditions. The objectives of these experiments were to assess the potential of geocentrifuge tests for the study of environmental problems, to investigate the effect of acceleration on the spreading of DNAPL, and to determine whether capillary pressure-saturation (P-c-S) curves of soils measured in a geocentrifuge are applicable under 1g conditions. In the present paper, numerical simulation is used in the interpretation of the experimental data and for checking, the suitability of the designed set-up. Based on these simulations, problems and difficulties regarding the current set-up are explored and suggestions for improvement in the experimental set-up for use in the study of multiphase flow in porous media are presented. We have demonstrated the importance of numerical simulations in the understanding of measured data through scenario analysis and matching numerical and experimental results. Numerical modeling is also shown to be important as an aid in the design of a complex experiment on multiphase flow. Also based on the experimental results and with the use of numerical simulation, we have concluded that the measured P-c-S curve in geocentrifuge is applicable for any practical application at 1g. (C) 2003 Elsevier Science Ltd. All rights reserved.