Mass transfer in the case of interfacial turbulence induced by the marangoni effect

A discussion concerning the mechanism of mass transfer is made by means of a physical model. In this model one considers that owing to interfacial turbulence a roll-cell structure is organized near the interface. The elements of liquid have a translatory motion with the average local velocity and a circulatory one in the roll-cell. Two limiting cases are discussed: (1) the elements of liquid keep their individuality without any change during the motion along the inside paths of the roll-cell; (2) the elements of liquid are completely refreshed during their inside motion. In the first limiting case the rate of mass transfer is increased as compared to that predicted by the penetration theory, since the time interval which an element of liquid spends at the interface is reduced. The second limiting case is similar to the renewal model. It is shown that these limiting cases have physical existence. By using a simulation procedure one concludes that the thickness of the roll-cell is of the same order of magnitude as its length. It is stressed that the treatment may be extended to wave motion and turbulent motion.