When liquid is added to a foam at sufficiently large flow rates, convective bubble motion will occur. Experiments are described in which the foam is confined in a tube which is tilted from the vertical. The theory of foam drainage is applied to this problem to show that the critical angle of tilt theta(c) at which convection occurs is related to the liquid flow-rate Q by theta(c) proportional t...

Recently, there have been many studies on dehumidifiers with a low flow rate of liquid desiccant, in which a plate-type heat exchanger with internal cooling is adopted. If the low flow rate of a liquid desiccant maintains a thin liquid film on the heat exchanger surface, heat and mass transfer performance would improve, the stability of the liquid film would increase, and there would be no entr...

The most prominent aspect of multiphase flow is the variation in the physical distribution of the phases in the flow conduit known as the flow pattern. Several different flow patterns can exist under different flow conditions which have significant effects on liquid holdup, pressure gradient and heat transfer. Gas-liquid two-phase flow in an annulus can be found in a variety of practical situat...

The Coulomb force applied by an electric field on any charge present in a dielectric liquid may cause fluid motion. At high applied electric fields in an insulating liquid, electric charge carriers are created at metallic/liquid interfaces, a process referred to as ion injection, and result from electrochemical reactions. In this article we deals with the problem of electro thermal convection i...

Experimental observations are reported for the laminar flow of a viscoelastic liquid through a symmetrical plane sudden expansion preceded by a gradual contraction from a square duct. As is well known, for Newtonian fluid flow above a critical Reynolds number the flowfield downstream of an expansion becomes asymmetric. For the viscoelastic liquid investigated here the asymmetry is greatly reduc...

The pleural space separating the lung and chest wall of mammals contains a small amount of liquid that lubricates the pleural surfaces during breathing. Recent studies have pointed to a conceptual understanding of the pleural space that is different from the one advocated some 30 years ago in this journal. The fundamental concept is that pleural surface pressure, the result of the opposing reco...

In this tutorial the fundamentals of non-boiling heat transfer in two-phase twocomponent gas-liquid flow in pipes are presented. The techniques used for the determination of the different gas-liquid flow patterns (flow regimes) in vertical, horizontal, and inclined pipes are reviewed. The validity and limitations of the numerous heat transfer correlations that have been published in the literat...