MASS TRANSFER OF A DISSOLVED SUBSTANCE IN A POROUS MEDIUM UNDER OSCILLATORY CONDITIONS
D. A. Polezhaev, A. V. Terekhina
Perm State Humanitarian Pedagogical University, Perm, Russia
Keywords: fluid flow, mass transfer, oscillation, porous medium, secondary flow
Abstract
We present an experimental investigation of the transport of water-dissolved rhodamine B fluorescent dye within a porous medium subjected to oscillatory flow. The porous medium consists of a rectangular cell packed with cylinders oriented perpendicular to the cell plane. The applied measurement technique enables simultaneous determination of the rhodamine B mass transfer rate and acquisition of both the instantaneous and time-averaged secondary flow velocity fields in the inter-cylinder space. The results demonstrate that the effective diffusion coefficient attributable to secondary flow scales linearly with the Peclet number, which is defined using the characteristic velocity of the secondary flow. At low dimensionless oscillation frequencies, a universal relationship is observed between the effective diffusion coefficient and the Peclet number. At moderate dimensionless oscillation frequencies, however, the proportionality constant between these parameters increases with rising oscillation frequency.
|
