Near-wall liquid film outflow of water-ethanol mixture from cylindrical channel into vacuum

The problem of joint near-wall liquid film ejection with gas flow from a cylindrical channel into vacuum is studied experimentally. A new technique for measuring thickness and velocity of the liquid film inside the channel with the help of capacity-type probes is presented. It is shown that co-current gas flow has strong impact on the near-wall film, leading to intense wave formation, detachment of droplets from the film surface, and formation of dry spots

Influence of the developing region of the thermal boundary layer on heat transfer during vapor condensation on horizontal tube bundles

The purpose of this publication is to describe a phenomenon that is fundamentally important and, at the same time, hardly elucidated in the literature. In the process of film condensation of vapor on the bundles of horizontal tubes, a developing region of the thermal boundary layer is formed on each tube of the bundle; the role of this region in heat transfer is important, and in some cases decisive. The paper presents experimental results on the influence of various contributions of the developing region on heat transfer during film vapor condensation on tube bundles. Based on the data obtained, an algorithm for calculating a condenser during condensation of a stationary vapor without non-condensable impurities is proposed