Bamboo grove

The fact that a liquid rises in a capillary tube is well-known. This experiment attempts to take a fresh look at the phenomenon. For their laboratory bamboo grove, the scientists created a foam in a glass by bubbling air through a soap solution. Since the bubbles are at a higher pressure than the atmosphere, they readily rise up the glass tubes one by one, each forming a lamella. However, the more the bubbles accumulate, the slower each new one entering the tube goes up. The aim is to investigate how foam confinement affects its flow, and more specifically the dissipation mechanism, located in the liquid channels connecting the soap films and the tube wall. Understanding this may be of help in applications using foams such as cleaning, especially of porous materials. This image was awarded the Jury's Favourite Award in the 2022 La preuve par l’image (LPPI) photography competition.