The entry of a falling film into a pool and the air-entrainment problem

Publisher Website
Google Scholar
Abstract
When a film of liquid runs down a vertical wall and enters a large pool a number of stationary horizontal ripples are observed on the film just above the point of entry. These ripples are explained and analysed by the method of matched expansions and the results have a bearing on more-complicated problems. Next the case when the wall itself is moving vertically downwards is analysed. This is of interest in roll-coating technology, where it is normally desired to achieve smooth entry of the descending film, without air entrainment. The paper gives sufficient conditions for smooth entry, and these are consistent with known experimental results.

This publication has 8 references indexed in Scilit: