German Title: Gekoppelte Transportprozesse in natürlichen porösen Medien
Translation of abstract (English)
As the interactions between transport processes are important for a number of interesting systems, a set of partial differential equations and appropriate parameter functions for the study of coupled water, heat, gas and solute transport was formulated and a state of the art computer model for the numerical solution of the equation system was created. A new phase pressure/partial pressure formulation for the coupled transport of liquid and gas phase was developed. The model was used to simulate the water and energy dynamics of a permafrost soil. A good qualitative agreement was achieved. Differences between modeled and measured data could be explained with heterogeneity in combination with the model's sensitivity to a change in hydraulic parameters. Water vapor and solute transport had no effect on the simulation result but transport of liquid water proved to be an important heat transfer process near 0 °C. The impact of the chosen parameterization and model on the simulation of a multistep outflow experiment was analyzed. Differences between a model based on Richards' equation and a twophase model only occurred when the Brooks-Corey parameterization was used. The results of the twophase model showed a retarded drainage and a hysteresis during imbibation which is in good agreement with experimental results.
|Supervisor:||Roth, Prof. Dr. Kurt|
|Date of thesis defense:||19 December 2001|
|Faculties / Institutes:||The Faculty of Physics and Astronomy > Institute of Environmental Physics|
|Controlled Keywords:||Poröser Stoff, Modellierung, Dauerfrostboden, Mehrphasenströmung, Bodenphysik|
|Uncontrolled Keywords:||Permafrostsoil physics , multiphase transport , permafrost , model , porous medium|