The effect of fingering phenomenon, occurring when one immiscible fluid displaces another having different viscosity within a porous medium, is studied. Fingering phenomena are encountered in the underground storage of natural gas in aquifers, in the recovery of petroleum, and in the subsurface movements of non-aqueous liquid pollutants. For example, an important problem in the storage process is the penetration of the gas into the water and its subsequent loss, which is exacerbated by the fingering effect. As the pressure of a displacing fluid increases, the fluid starts to penetrate into the displaced fluid. When this pressure exceeds the bubble pressure, the natural gas begins to be lost into the water. The magnitude of the loss depends on the pressure of the fluid which is penetrating, the porosity of the medium, and on the microscopic conductivity of the medium. Flow visualization of such flow in a simulated porous medium can assist in verifying analytical or numerical models.
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