[Model equations for graviosmotic flows in double-membrane system].

On the basis of Kedem-Katchalsky equations the model equations for graviosmotic flows was elaborated. The validity of this model for aqueous glucose solutions was verified, using a Kargol's double-membrane cell. In the cell, volume flux was measured as a function of time and solution concentrations. These experimental findings are interpreted in terms of a gravitational instability that reduced concentration boundary layers dimensions. A critical values of concentration Rayleigh number for membrane transport is used in a mathematical model for gravitationally sensitive volume flows.