FEATURES OF THE FILM FLOW OF A LIQUID OVER A VERTICAL SURFACE IN A TRANSVERSE MAGNETIC FIELD

Abstract

One of the actual problems of magnetohydrodynamics is the problem of the flow of electrically conductive liquids in thin liquid layers in the presence of a transverse magnetic field. Unfortunately, studies of these problems have not been sufficient so far. The influence of a transverse magnetic field can affect a number of factors: the change in the viscosity of the flow due to the magnetic field on the physico-chemical characteristics of the medium; manifestation of the effect of flow deceleration, which can have a significant effect on the hydrodynamic characteristics of the film flow in the processes of heat and mass transfer. In this regard, in this work was made an attempt to consider the influence of a constant magnetic field on the formation of a thin liquid layer on a vertical surface under the action of ponderomotive forces. As known, ponderomotive forces in the case under consideration can lead to a number of effects associated with a change in viscosity and flow deceleration. To a greater extent, this can manifest itself in thin liquid layers, depending on the ratio of gravitational forces, inertia forces and forces of a magnetic nature. An analysis of the influence of this phenomenon in the considered case of thin liquid layers, as shown in the work, significantly affects the length of the hydrodynamic initial section, the thickness of the liquid layer, and the damping of wave motion in the zone of stabilized flow. Recommendations for calculating these characteristics are presented in this article, in which much attention is paid to the definition of the liquid layer, depending on the ratio between the forces of inertia and the forces of a magnetic nature. An expression was also obtained for determining the distribution of velocities in the zone of a stabilized film flow in a transverse magnetic field. Thus, by comparing the expression for determining the distribution of velocities in a film without the influence of a magnetic field with the expression in the presence of a magnetic field, one can estimate the effect of ponderomotive forces on the flow of a liquid film.