Propagation of fluids in porous media / Propagação de fluidos em meios porosos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The growth of rough interfaces has become an intense field of research in the last years. Particulary, imbibition experiments, in which a suspension (for example ink) is imbibed into a disordered medium, have being performed in ordes to characterize the roughness of the surface produced. The objective of this work is to investigate experimentally the interfaces generated by the movement of ink in newspaper samples in order to verify the behavior of the interface roughness with time and orientations of the paper. A sample of newspaper is kept vertically with the lower extremity immersed in an ink reservoir. The ink is absorbed into the paper, creating a rough interface that moves upward. At determined time intervals the sample is photographed with a digital camera. After some days the interface roughness reaches a stationary (pinned) state. The photographs are processed in order to produce a two color picture (black for the ink part and white for the dry part). A computer program is used to extract the height of each pixel of the interface and another one calculates the roughness of the interface. These parameters are used in the determination of the growth, β, Hurst, H, and Washburn, δ, exponents. This is done for two orientations (perpendicular to each other) of the samples. The results indicate a possible dependence of the exponents δ and H with sample orientation.

ASSUNTO(S)

crescimento de superfícies imbibition functions of scale fisica da materia condensada roughness growth of surfaces funções de escala rugosidade embebição

ACESSO AO ARTIGO

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