Experimental Study On Point Source Infiltration And Interfacial Area In Porous Media By X-ray Computed Microtomography

Theoretical and applied research in micro geometrical characteristic in porous media hasreceived increased attention in many engineering applications, which is due to this reaearch areaplay a key role in multiphase flows, heat, and mass transfer. In this study based on Micro-CTexperiment platform, point source infiltration, interfacial areas examination between water andair phase, and fractal dimensions are quantified investigated under micro-scale, which shed lighton deeper recognition of dynamics and morphology in porous media. Main results are listed asfollows:Physical and micro mechnical properties are determined by drying temperature in colloidporous media of which solid phase is characterized by hydrophilic expansion. Hence, particularmoisture transport path and mechanism are present, including diffrences comparison withinwetting front, infiltration depth, and change of porosity for samples under different dryingtemperature. Compared with cake samples dried in temperature of100℃and120℃, that of80℃are revealed in obvious physical and micro mechnical properties.2D and3D water distributions in unsaturated glass beads pack porous media under differentsaturations are studied. The microscale distributions of water are also verified by Euler numberwhich is an indicator of connectedness of complex water flow morphology. Further, the resultssignificantly show that the maximum value of water-air interfacial area occurs at saturation rangefrom20%to35%by contrasting variation relationship between water-air interfacial area andsaturation within different solid partical sizes.Fractal dimension is comprehensively determined by phase volume fraction (solid phasevolume fraction or porosity) and the inherent complexity of phase morphology. Additionally, thefractal dimension of solid phase is greater than that of pore phase in both types of porous media.However, variation between fractal dimension of pore phase and porosity is revealed to bedifferent, which is due to alternative domination of the two influence factors mentioned above.