A dynamic theory of mass transfer at a wavy interface

Abstract

AbstractA new theory to predict mass transfer at an interface undergoing stationary oscillations is presented. The theory describes mass transfer when a slightly soluble gas is dissolving in a dynamic liquid interface. It is shown that mass transfer under these conditions is a function of the square of wave amplitude, and depends, in a complex way, on a characteristic Schmidt and Reynolds number. The latter quantities are defined in terms of the characteristic wave‐length and frequency of the system periodicity. In the limit of large Reynolds and Schmidt numbers, which characterize most real liquid‐gas systems, the theory takes a particularly simple form and shows that the ratio of the mass fluxes for dynamic to stagnant interfaces is independent of Schmidt number and depends only on the square of the amplitude‐wave length ratio and the square root of the Reynolds number. Using the Kapitsa hydrodynamic parameters, the mass transfer theory is compared with data from a wetted‐wall column.