Extraction of material from a porous body into a moving liquid

The nonstationary process of extracting material from a porous body simulated by a system of semi-infinite capillaries into a moving liquid is studied; the transfer rate of the material in the flow is a linear function of the cross flow coordinate. The case where the liquid velocity at the interface becomes zero is considered. It is assumed that the diffusion in the flow is quasi-stationary. Analytical dependences at the boundary of the porous material and the flow region are found for mass transfer characteristics of practical interest (concentration, diffusion flow, total diffusion flux and the total yield of the target component through the cross section of the porous body).