Critical regimes of upward film flows in vertical annular channels

Abstract

Systematic experimental studies of upward film flows in vertical annular channels were conducted that were based on measuring liquid film thickness by an acoustic method. The method arose from the dependence between resonance characteristics of a piezoceramic transducer and the mass of liquid on its surface. The experimental data obtained on the limits of stability for upward film flows were generalized, and a flow regime diagram was constructed. Finally, some correlations were developed for calculation of critical regimes of flow and heat transfer in annular evaporating channels.