Scaling effect of breakthrough character in porous media

Breakthrough phenomenon during fluids percolating through wet saturated por ous layer is widely met in the study of heat and mass transfer in porous me dia. Breakthrough pressure (BP) is a characteristic pressure that indicates the intrinsic properties of seepage within porous media. Measuring results of BP for saturated narrow-sieved sand are reported here. The curve of BP varying with the height of porous layer was obtained. Experiment and analys is indicate that BP is independent of the height of particle packed layer i f thick enough; however, when the height is less than a certain critical va lue, BP diminishes with the decrease of the height according to a universal scaling law.