The Study of Two-Phase Flow Model for Infiltration

Abstract

Infiltration is an important component in hydrogeological research Most of the existing infiltration theories are constructed based on single-phase model for water movement and those models do not account for the movement of gas phase This study investigated the infiltration process using two-phase model The liquid expels air in the soil void to generate the two-phase flow The air extrudes the initial moisture content in the soil ahead of the wetting front such that the water content decreases With the wetting front arrived the water content rapidly increases to reach equilibrium Therefore the water content falls at first and rises later in the infiltration process This study explores the application of two-phase model to the experimental data In the theoretical part the fluids are assumed incompressible The travel distance of fluid migration for given saturation were calculated by Buckley and Leverett [1942] model The results are used to describe the movement of water front and air front and also the water content changes of the soil profile In the sand box experiments the ponded water head is remained constant Variation of water content with time at three different depths are recorded Three experiment sets were design Each set is performed for three times The model was applied to the experimental data The results show that the two-phase infiltration model is applicable to describe the infiltration process However the quantitative assessment can be improved by relaxing the assumptions

Date of Award	2015 Feb 24
Original language	English
Supervisor	Kuo-Chin Hsu (Supervisor)