New concepts on the mechanisms of flooding and flow reversal phenomena

Abstract

A film model for flooding and flow reversal has been explored for two cases of coupling (circulation) or decoupling (split) between the upflow and downflow. It is shown that for a given interfacial shear (parameter) there exists multiple solutions and oscillation between the possible states takes place. Thus, it would appear that large waves are formed, but in fact the flow is controlled by film equations. The multiple states of the film and the switching mechanism between the slates are supported exceptionally well by experimental findings of mean and fluctuating film thickness and pressure drop.