Experimental validation and applications of a fluid infiltration model

Horizontal infiltration experiments were performed to validate a plug flow model that minimizes the number of parameters that must be measured. Water and silicone oil at three different viscosities were infiltrated into glass beads, desert alluvium, and silica powder. Experiments were also performed with negative inlet heads on air-dried silica powder, and with water and o il infiltrating into initially water moist silica powder. Comparisons betwe en the data and model were favorable in most cases, with predictions usuall y within 40% of the measured data. The model is extended to a line source a nd small areal source at the ground surface to analytically predict the sha pe of two-dimensional wetting fronts. Furthermore, a plug how model for con stant flux infiltration agrees well with field data and suggests that the p roposed model for a constant-head boundary condition can be effectively use d to predict wetting front movement at heterogeneous field sites if average d parameter values are used.